Rice Pests and Diseases Around the World: Literature-Based Assessment with Emphasis on Africa and Asia

Round 1

Reviewer 1 Report (New Reviewer)

Comments and Suggestions for Authors

The manuscript is important. However, please address the following suggestion for further improvement-

1. The title is clear and informative. Although some regions are underrepresented, it might be more accurate to specify the focus, such as "A Global Overview with Emphasis on Asia and Africa."
2. The manuscript compiles a comprehensive dataset on rice pests and diseases, which fills gaps in understanding global distribution patterns. However, the study relies solely on literature-based data, which may exclude unpublished or field-based studies.
3. The abstract mentions findings but does not include specific percentages or data points that could strengthen its claims. Additionally, this section lists pests and diseases in Africa and Asia but does not explain why these continents are a focus. This should be stated if these regions were emphasized due to data availability or rice production scale.
4. The last sentence of the abstract suggests that the study contributes to understanding management in the context of climate change, but this aspect is not developed in this section. You can add a sentence on practical applications that would enhance its relevance.
5. Please ensure uniformity in referring to rice species. Sometimes, Oryza sativa and Oryza glaberrima are mentioned in different formats. Please italicize them consistently.
6. The introduction mostly focuses on rice production and geography before briefly mentioning pests and diseases at the end. You can introduce the topic of pests and diseases earlier to align better with the research focus.
7. Lines 60-63 are vague. You can specify whether the study addresses this gap by compiling scattered data.
8. The study covers 78 countries; however, it excludes 34% of rice-producing nations. Notably, Myanmar, one of the world's major rice producers, is absent from the dataset. You can add the reasons behind these gaps in the “Geographical Distribution of the Records” section. In addition, the analysis relies on published research articles. However, some countries may have extensive pest and disease issues but lack published studies. Please explore alternative data sources (e.g., government reports, industry surveys) could enhance coverage.
9. The “Pests affecting rice production” section could be strengthened by providing more quantitative data on the actual yield losses caused by each major pest. This section effectively compares African and Asian pests, but please add a brief comparison with other regions, which would provide a more global perspective. In addition, this section relies heavily on literature reviews, you can incorporate more field-based data and case studies.
10. “Diseases affecting rice productivity” section discusses the impact of diseases but lacks information on mitigation or control measures. You can add a brief overview of existing disease management strategies (e.g., resistant varieties, fungicides, or biocontrol).
11. “Overall assessment of rice pests” section relies heavily on previously established pests. Here, you can mention any emerging threats due to climate change, shifts in agricultural practices, or pesticide resistance.
12. Lines 428-433 indicate taxonomic details, but these lines could be simplified. You can mention the species followed by their agricultural impact in these lines.
13. “Overall assessment of rice diseases” section could explore how climate change might influence the spread and severity of these diseases. For example, rising temperatures and changing rainfall patterns could alter the distribution of vectors like Nephotettix species or the prevalence of fungal diseases like Blast. In addition, you can add some data on emerging or re-emerging rice diseases and their potential impact on global rice production. For example, are there any new viral or fungal pathogens becoming a concern in certain regions?

Author Response

Reviewer 1 comments

The manuscript is important. However, please address the following suggestion for further improvement.

Specific comments

Q1. The title is clear and informative. Although some regions are underrepresented, it might be more accurate to specify the focus, such as "A Global Overview with Emphasis on Asia and Africa."

R1. Thank you for your suggestion, the title was changed accordingly and now reads as follows: “Rice Pests and Diseases Around the World: A Literature-Based Assessment with Emphasis on Africa and Asia”.

Q2.  The manuscript compiles a comprehensive dataset on rice pests and diseases, which fills gaps in understanding global distribution patterns. However, the study relies solely on literature-based data, which may exclude unpublished or field-based studies.

R2. We sincerely appreciate this comment, and agree that the work is based on literature-based data following the PRISMA guidelines for systematic reviews, which includes the literature retrieved from selected databases using predefined keywords. We are aware that this approach may exclude unpublished or other field-based studies that have not been published as articles. Since our methodology relies on three publicly available literature databases, unpublished studies and other publication forms (namely grey literature, reports, or unpublished data) are often not included in these databases. Given the large volume of data analysed, and to ensure methodological consistency this limitation was considered an acceptable loss.

Q3. The abstract mentions findings but does not include specific percentages or data points that could strengthen its claims. Additionally, this section lists pests and diseases in Africa and Asia but does not explain why these continents are a focus. This should be stated if these regions were emphasized due to data availability or rice production scale.

R3. Thank you for your comment. We have included specific data points to strengthen our claims in the Abstract. Additionally, the focus on Africa and Asia was clarified, mainly due to high availability of literature in these regions, thus reflecting the occurrence of studies on major rice-producing regions and also higher scientific knowledge generated on these regions in comparison to other regions (e.g. Americas).

(Lines 23-24) “Findings highlight a regional focus on Africa and Asia, where rice is predominantly produced.”.

Moreover, the lack of studies in major rice producing countries such as Myanmar was mentioned in the Abstract: (L34-35) “The lack of data from major rice producers like Myanmar highlights reporting gaps, urging future research.”.

Q4. The last sentence of the abstract suggests that the study contributes to understanding management in the context of climate change, but this aspect is not developed in this section. You can add a sentence on practical applications that would enhance its relevance.

R4. To address the reviewer comment, a new sentence was included to highlight practical applications of our findings on the management of pests and diseases in the context of climate change at the abstract (L35-L38): “This study enhances global understanding of rice pests and diseases distribution and their impacts on productivity. It could also support early warning systems and assess the effectiveness of control methods in the context of climate change.”.

Additionally, and following the reviewer comment, a new sentence was included at the end of the Introduction Section to counteract the contribution of the current study to the practical applications of pests and diseases in the context of climate change, at L208-213: “By mapping the distribution of pests and diseases, this study could contribute to the development of early warning systems, as well as evaluating either existing pest and disease control methods remain effective under changing climate conditions, in specific countries and/or regions. Additionally, distribution trends can help predict future outbreaks and inform proactive management strategies.”.

Q5. Please ensure uniformity in referring to rice species. Sometimes, Oryza sativa and Oryza glaberrima are mentioned in different formats. Please italicize them consistently.

R5. Thank you for the comment. In the manuscript, both scientific names of rice species were written in the full form ‘Oryza sativa’ and ‘Oryza glaberrima’ for the first time, and thereafter the genus name was abbreviated (e.g., ‘O. glaberrima’). This format has been uniformized throughout the manuscript to ensure consistency.

Q6. The introduction mostly focuses on rice production and geography before briefly mentioning pests and diseases at the end. You can introduce the topic of pests and diseases earlier to align better with the research focus.

R6. Thank you for your valuable suggestion. The section of pests and disease at the Introduction was completely rewritten to align with better focus on pests and diseases, as per reviewer suggestion, and can now be read as follows (L72-110):

“While the biotic network naturally controls most rice pests, a small number of insect species consistently pose a significant threat. According to Heinrichs and Muniappan [5], only 20 species in tropical Asia, 15 in Africa, and 20 in the Americas are of major economic importance, categorized as root and stem feeders, stem borers, gall midges, hoppers, foliage feeders, and panicle feeders. These pests, along with various diseases, can cause severe yield losses worldwide, sometimes reaching up to 60% [19].

Rice production is particularly affected by stem borers, hoppers, and defoliators. A meta-analysis on yield impacts caused by a complex of stem borers in Asia found that a 1% increase in whiteheads corresponds to a 4% reduction in yield [20]. In this country, major stem borers include Scirpophaga incertulas, which can cause yield losses ranging from 3 to 95% in India [21], and Chilo suppressalis [22]. In West Africa, key species such as Diopsis macrophthalma, Maliarpha separatella, Chilo zacconius, and Sesamia calamistis pose significant threats [5]. Additionally, rice gall midges (Orseolia spp.) affect rice production in both Asia and West Africa [19]. Hoppers, including leafhoppers (Cicadellidae) and planthoppers (Delphacidae), not only cause direct feeding damage but also serve as a vector for viral diseases such as rice tungro, Rice Transitory Yellowing, ‘hoja blanca’ virus, and Rice Yellow Mottle Virus (RYMV) [23-25]. Defoliators such as rice leaffolders (Cnaphalocrocis spp.), armyworms (Mythimna separata, Spodoptera frugiperda), and swarming caterpillars (Spodoptera mauritia) significantly reduce photosynthesis and damage panicles [5]. Additionally, coleopteran pests, including African hispids and flea beetles, serve as vectors of RYMV [5]. Although numerous insect species attack rice, only a subset inflicts severe economic losses, highlighting the need for effective pest management strategies.

Rice diseases, caused by fungi, bacteria, viruses, and nematodes, affect various plant parts and significantly impact yields [26]. Among fungal pathogens, rice Blast (Pyricularia oryzae) is the most destructive globally, affecting all growth stages and manifesting as leaf blast, neck rot, and panicle blast [5,27,28]. Bacterial Blight (Xanthomonas oryzae pv. oryzae) is the most severe bacterial disease, widespread except in Europe [29]. While viral diseases generally cause minor losses, outbreaks can be devastating. In Asia, Rice Tungro Spherical virus (RTSV) and Rice Grassy Stunt virus are major threats [30,31], ‘hoja blanca’ dominates in the Americas [23], and RYMV is the primary rice virus in Africa [32]. Nematodes also pose serious risks. The rice stem nematode (Ditylenchus angustus) causes Ufra disease, leading to 20%–90% yield losses in Asia. The root-knot nematode (Meloidogyne graminicola), widespread in flooded conditions, can result in up to 80% losses in upland rice and 73% in irrigated systems. Other damaging species include the white tip nematode (Aphelenchoides besseyi), and rice cyst nematodes (Heterodera spp.) [33]. Managing these pests and diseases is critical for ensuring stable rice production and food security.”.

Q7. Lines 60-63 are vague. You can specify whether the study addresses this gap by compiling scattered data.

R7. Thank you for the suggestion, the text was revised for clarity and now it can be read as follows at L67-71: “All over the world, pests and diseases are major constraints to rice production [18]. From production to consumption, approximately 800 insect species can attack rice [15], but this information is often scattered and lacks systematic compilation. This study aims to address this gap by compiling and analysing the existing published data on rice insect pests and diseases.”.

Q8. The study covers 78 countries; however, it excludes 34% of rice-producing nations. Notably, Myanmar, one of the world's major rice producers, is absent from the dataset. You can add the reasons behind these gaps in the “Geographical Distribution of the Records” section. In addition, the analysis relies on published research articles. However, some countries may have extensive pest and disease issues but lack published studies. Please explore alternative data sources (e.g., government reports, industry surveys) could enhance coverage.

R8. Thank you for the comment and suggestion. Although we agree on the relevance of alternative information, the methodology of this review follows the PRISMA guidelines and focuses on published articles retrieved from three databases, which generally exclude governmental and technical reports. To clarify this limitation, a new sentence was added to the Discussion section, L488-492: “The lack of rice-producing countries in the explored databases may be due to relevant research being published in non-indexed sources like technical reports or government documents. This highlights the need for more peer-reviewed scientific articles to enhance accessibility and understanding of pest and disease dynamics in these regions.”

Q9. The “Pests affecting rice production” section could be strengthened by providing more quantitative data on the actual yield losses caused by each major pest. This section effectively compares African and Asian pests, but please add a brief comparison with other regions, which would provide a more global perspective. In addition, this section relies heavily on literature reviews, you can incorporate more field-based data and case studies.

R9. Thank you for your suggestion. This section is part of the Results section and, as such, it is based solely on articles retrieved following the systematic PRISMA guidelines methodology. A new sentence was added to accommodate the limited representation of other continents at L373-378: “With limited representation, in the American continent (40 records from 29 articles), rice damage is primarily associated with the stink bug genus Oebalus (Hemiptera). In Europe (6 records from 5 articles) the most common species is the rice water weevil, Lissorhoptrus oryzophilus (Coleoptera). Data from Oceania is represented by only 2 records from a single article. Given this limited representation, any conclusions derived from these continents should be interpreted with caution.”.

Concerning the data on yield losses, it is important to consider that field conditions are quite complex: various abiotic, chemical, geological, and biotic factors interact, making yield loss highly variable for the same pest. Additionally, pests are mainly mobile individuals, making yield loss even more challenging to characterize. In the field, rice plants do not exist alone, and multiple, less evident organisms may contribute to the observed losses, potentially amplifying the yield loss under study. Most studies mention yield losses in a qualitative rather than quantitative way. Even when quantitative % values are presented, the range is usually relatively large and varies from study to study. To accommodate this reality, two sections were revised, Introduction and Discussion. The Introduction section has been rewritten and concised with a special attention on the section on pests, with a note concerning yield losses, which can now be read as follows (L79-95): “Rice production is particularly affected by stem borers, hoppers, and defoliators. A meta-analysis on yield impacts caused by a complex of stem borers in Asia found that a 1% increase in whiteheads corresponds to a 4% reduction in yield [20]. In this country, major stem borers include Scirpophaga incertulas, which can cause yield losses ranging from 3 to 95% in India [21], and Chilo suppressalis [22]. In West Africa, key species such as Diopsis macrophthalma, Maliarpha separatella, Chilo zacconius, and Sesamia calamistis pose significant threats [5]. Additionally, rice gall midges (Orseolia spp.) affect rice production in both Asia and West Africa [19]. Hoppers, including leafhoppers (Cicadellidae) and planthoppers (Delphacidae), not only cause direct feeding damage but also serve as a vector for viral diseases such as rice tungro, Rice Transitory Yellowing, ‘hoja blanca’ virus, and Rice Yellow Mottle Virus (RYMV) [23-25]. Defoliators such as rice leaffolders (Cnaphalocrocis spp.), armyworms (Mythimna separata, Spodoptera frugiperda), and swarming caterpillars (Spodoptera mauritia) significantly reduce photosynthesis and damage panicles [5]. Additionally, coleopteran pests, including African hispids and flea beetles, serve as vectors of RYMV [5]. Although numerous insect species attack rice, only a subset inflicts severe economic losses, highlighting the need for effective pest management strategies.”;

At the Discussion section, a new sentence was added at L625-629: “Nevertheless, it is important to note that while many yield losses studies are conducted in controlled environments, field studies conditions are far more complex, with various abiotic, chemical, geological, and biotic factors interacting, making yield loss highly variable and potentially influenced by multiple, less evident organisms, or other factors.”.

Q10. “Diseases affecting rice productivity” section discusses the impact of diseases but lacks information on mitigation or control measures. You can add a brief overview of existing disease management strategies (e.g., resistant varieties, fungicides, or biocontrol).

R10. This work followed a systematic methodology, where management strategies were excluded (L248-251) as described in the Material and Methods section: “(...) 1^st exclusion criterion (...) records not directly related to the subject, including at least one of the four disciplines: medical/ veterinary and biotechnology; molecular biology/ resistances/ tolerances of rice varieties; agricultural practices/ farmer perceptions; other crops.”. This selection of criteria was carried out to ensure a clear focus on the objectives of the study. Nevertheless, to address the pertinent reviewer comment, we have included a sentence at the Discussion section (L680-692) as follows: “Effective rice disease management maximizes yields, ensures food security, and supports sustainable farming. Key strategies include genetic resistance breeding, biological control, cultural practices, and responsible chemical use. Advances in molecular breeding have led to the development of resistant rice varieties against major diseases like rice Blast [100] and Bacterial Leaf Blight [101]. Biological control using microorganisms like Pseudomonas fluorescens, which demonstrate antagonistic effects against pathogens such as Bipolaris oryzae, reduces reliance on chemical pesticides [102]. Cultural practices such as integrated pest and disease management (IPM and IDM, respectively), water regulation, and crop rotation have been shown to reduce disease incidence [103-104]. Additionally, farmer education plays a key role in strengthening these efforts. Technology-driven methods, like predictive modelling, aid early detection [105], reducing yield losses. A holistic approach integrating these strategies strengthens rice production and sustainability.”

Q11. “Overall assessment of rice pests” section relies heavily on previously established pests. Here, you can mention any emerging threats due to climate change, shifts in agricultural practices, or pesticide resistance.

R11. Thank you for your suggestion on including emerging threats, which we have taken in consideration by including two new sentences at the section “Overall assessment of rice pests” at the Discussion at 518-522: “As climate change reshapes agricultural ecosystems, Diopsis is emerging as a more significant threat to rice production, namely due to the rising temperatures that accelerate the life cycle of Diopsis, leading to increased population growth and more frequent infestations, particularly in Africa [60].”, and at L543-550: “The climate changing is intensifying the threat posed by key rice pests in Asia, leading to greater crop losses and food security concerns. Rising temperatures are increasing pest activity and disease transmission, particularly for Nephotettix spp. (green leafhoppers), which transmit the Rice Tungro Virus, and Nilaparvata lugens (brown planthoppers), which spread Rice Grassy Stunt and Ragged Stunt Viruses. To mitigate these impacts, a combination of adaptive pest management, climate-resilient rice varieties, and improved monitoring systems adapted to region-specific climate conditions is essential.”.

Q12. Lines 428-433 indicate taxonomic details, but these lines could be simplified. You can mention the species followed by their agricultural impact in these lines.

R12. Thank you for your suggestion. We have simplified the taxonomic details by including causal agent species after the name of the respective disease. The text can now be read as follows (L471-475): "Bakanae disease (Fusarium fujikuroi) is exclusively seed-borne, while Bacterial Leaf Blight (Xanthomonas) affects only the leaf. Blast disease (Pyricularia oryzae) is documented to impact the leaf, panicle, and neck. Rice Spikelet Rot disease (Curvularia lunata) is confined to the panicle, whereas Sheath Blight (Rhizoctonia solani), primarily affecting the sheath, is also recorded on the panicle.”.

Q13. “Overall assessment of rice diseases” section could explore how climate change might influence the spread and severity of these diseases. For example, rising temperatures and changing rainfall patterns could alter the distribution of vectors like Nephotettix species or the prevalence of fungal diseases like Blast. In addition, you can add some data on emerging or re-emerging rice diseases and their potential impact on global rice production. For example, are there any new viral or fungal pathogens becoming a concern in certain regions?

R13. Thank you for your insightful comment. We have incorporated your suggestion by including a new sentence to highlight how the environmental conditions could influence the emergence and expansion of rice diseases as well as vectors of virus diseases at L572-579: “Climate change is increasing the spread and severity of rice diseases by altering environmental conditions. Rising temperatures and shifting rainfall patterns favour fungal pathogens like rice Blast and expand the range of insect vectors such as Nephotettix species, which transmit Rice Tungro Virus disease. Extreme weather events further weaken plant defenses, increasing the frequency of disease outbreaks. Additionally, climate change disrupts biological pest control, intensifying disease pressure. To mitigate these risks, Climate Smart Agriculture Practices (CSAP) can help protect rice yields and enhance ecosystem resilience [69].”.

Reviewer 2 Report (New Reviewer)

Comments and Suggestions for Authors

The review on ‘rice pests and diseases around the world: A literature-based assessment’ is interesting. I think, it helps the readers understand the impact of rice pests and diseases and develop effective management strategies.

Specific comments:

Line 167-181: The terms explained in square brackets and the alphabets used like (a) and (b) are confusing. Please rewrite them in a simplified way to help readers understand better.

Line 239-244: How did the authors extract the data for the articles published in other languages?

Figure 3: Are these images the original contribution from authors? If not, please provide appropriate credits.

Author Response

Reviewer 2 comments

The review on ‘rice pests and diseases around the world: A literature-based assessment’ is interesting. I think, it helps the readers understand the impact of rice pests and diseases and develop effective management strategies.

Specific comments

Q1. Line 167-181: The terms explained in square brackets and the alphabets used like (a) and (b) are confusing. Please rewrite them in a simplified way to help readers understand better.

R1. Thank you for your suggestion, we have revised the text to improve clarity and readability, by removing the square brackets and alphabet letters. Now it reads as follows (L220-240): “Following the PRISMA guidelines [34], a set of specific keywords combination were searched according to four search queries: i) rice pests and diseases characterization in the world; ii) rice pests and diseases characterization in Africa; iii) rice pests and diseases characterization in West Africa; iv) characterization of mangrove rice pests and diseases - from world to West Africa (the main rice-producing region within mangrove agroecosystem and the pivotal region of African rice - O. glaberrima - production). Different combinations of keywords using ‘AND’ included ‘Oryza sativa’, ‘Oryza glaberrima’, ‘rice’ ‘disease’, ‘pest’, ‘africa’, ‘west africa’, and ‘mangrove rice’. The complete keywords combination as well as Boolean operators applied to each bibliographic database is detailed at Table S1.”.

Q2. Line 239-244: How did the authors extract the data for the articles published in other languages?

R2. Thank you for your question. Most articles published in other languages besides English had only the abstract available. In these cases, as well as when the full article was available, translation tools were used to extract the most relevant information. To clarify this process, a new sentence was added to the Methods section at L242-244: “Whenever articles in languages other than English were analysed, a standard translation tool (Google Translator) was used to extract the most relevant information.”.

Q3. Figure 3: Are these images the original contribution from authors? If not, please provide appropriate credits.

R3. Thank you very much for noticing this concern. All copyright identities © were added to each image of Figure 3, as well as in Figure 5.

Reviewer 3 Report (New Reviewer)

Comments and Suggestions for Authors

The manuscript is interesting and it may useful in the field of agricultural (rice) pest and disease management. This review article is systematic and well prepared. Rationale of the review is very clear in the introduction section and the methods, results and discussions are well described with relevant literature. I would like to suggest the following comments from the manuscript for consideration before publication.

Line 38: Scientific name of rice was mentioned in the full form ‘Oryza sativa’ as first time. Then, second time onwards write abbreviated genus name for the same genus. Like ‘O. glaberrima’ instead of ‘Oryza glaberrima’ (line 38), ‘O. sativa’ instead of ‘Oryza sativa’ (line 39), ‘O. barthii’ instead of ‘Oryza barthii’ (line 42) and throughout the manuscript.

Line 39-40: Add reference for the statement “Oryza sativa was initially cultivated in Southeast Asia, somewhere in India, Myanmar, Thailand, North Vietnam, or China, between 8000 and 15000 years ago.”.

Line 60: Add reference for “800 insect species” or write in general way without specific number.

Line 69-111: Please simplify the descriptions and specifications of insect names and other details. All the informations may provide in a table with the details of scientific names, synonyms, common names, organism order, country/region and website link/reference.

Line 149: Write expansion of PRISMA.

Line 166-182: Specific keywords are provided. However, keywords of scientific names may be provided with binomial nomenclature (first letter of genus name in capital letter and name in italic font).

Line 186: What are the three databases?. Specify.

Please increase the font size of markings/remarks in the figure 2 (country names), figure 3 (species names), figure 5 (all markings), figure 7 (all markings),

Line 413: Write expansion of EPPO.

Please check the typographical errors and grammatical errors throughout the manuscript.

Author Response

Reviewer 3 comments

The manuscript is interesting and it may useful in the field of agricultural (rice) pest and disease management. This review article is systematic and well prepared. Rationale of the review is very clear in the introduction section and the methods, results and discussions are well described with relevant literature. I would like to suggest the following comments from the manuscript for consideration before publication.

Specific comments

Q1. Line 38: Scientific name of rice was mentioned in the full form ‘Oryza sativa’ as first time. Then, second time onwards write abbreviated genus name for the same genus. Like ‘O. glaberrima’ instead of ‘Oryza glaberrima’ (line 38), ‘O. sativa’ instead of ‘Oryza sativa’ (line 39), ‘O. barthii’ instead of ‘Oryza barthii’ (line 42) and throughout the manuscript.

R1. Thank you for the correction. The scientific names have been revised accordingly to ensure consistency throughout the manuscript.

Q2. Line 39-40: Add reference for the statement “Oryza sativa was initially cultivated in Southeast Asia, somewhere in India, Myanmar, Thailand, North Vietnam, or China, between 8000 and 15000 years ago.”.

R2. As per reviewer comment, reference [5] was added at the end of the sentence to properly cite its contents.

Q3. Line 60: Add reference for “800 insect species” or write in general way without specific number.

R3. Thank you for the suggestion. Reference [15] was added to the statement.

Q4. Line 69-111: Please simplify the descriptions and specifications of insect names and other details. All the informations may provide in a table with the details of scientific names, synonyms, common names, organism order, country/region and website link/reference.

R4. Thank you for your suggestion. The insect names descriptions presented in the manuscript were simplified and a new Supplementary Table (Table S2) was created to accommodate synonyms information. This table includes the insect orders, family, (accepted) scientific name, synonyms, the EPPO [https://gd.eppo.int/] code, common names, host plants and its respective distribution by continents. This table is now cited in the manuscript in Methods and Results sections at L272-274: “Data on insect pests taxonomy, its synonyms, common names, host plants and their respective distribution by continents, according to the literature screened, was compiled at Table S2.”; and L364: “Please check Table S2 for insect pest synonyms and other relevant data.”.

Q5. Line 149: Write expansion of PRISMA.

R5. Thank you for your suggestion. Expansion of PRISMA was added at the first time mentioned at L198-199: “(...) performed according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines (...)”.

Q6. Line 166-182: Specific keywords are provided. However, keywords of scientific names may be provided with binomial nomenclature (first letter of genus name in capital letter and name in italic font).

R6. Thank you for your suggestion, which have been corrected accordingly. In the revised manuscript, this section was simplified and can now be read as follows at L220-240: “Following the PRISMA guidelines [34], a set of specific keywords combination were searched according to four search queries: i) rice pests and diseases characterization in the world; ii) rice pests and diseases characterization in Africa; iii) rice pests and diseases characterization in West Africa; iv) characterization of mangrove rice pests and diseases - from world to West Africa (the main rice-producing region within mangrove agroecosystem and the pivotal region of African rice - O. glaberrima - production). Different combinations of keywords using ‘AND’ included ‘Oryza sativa’, ‘Oryza glaberrima’, ‘rice’ ‘disease’, ‘pest’, ‘africa’, ‘west africa’, and ‘mangrove rice’. The complete keywords combination as well as Boolean operators applied to each bibliographic database is detailed at Table S1.”. Also Figure 1 has been updated with the corrected keyword of scientific names of rice species.

Q7. Line 186: What are the three databases?. Specify.

R7. The databases were previously mentioned at L217-220: “(...) three databases were used: PubMed (https://pubmed.ncbi.nlm.nih.gov/, 20 April 2024), Web of Science (WOS) (https://www.webofscience.com/, 20 April 2024), and CAB Abstract (https://www.cabdirect.org/, 20 April 2024).”; now the three databases designations were also included in the mentioned sentence, as per reviewer suggestion (L245-246): “For the three databases (PubMed, WOS, CAB Abstract), searches were restricted to the title and abstract.”.

Q8. Please increase the font size of markings/remarks in the figure 2 (country names), figure 3 (species names), figure 5 (all markings), figure 7 (all markings),

R8. Thank you for your suggestion. The font size of the markings/observations in Figures 2, 3, 5 and 7 has been increased and all the revised figures were included in the revised manuscript.

Q9. Line 413: Write expansion of EPPO.

R9. Thank you for your suggestion. The full expansion of EPPO was added at the first mention at L492-493: “(...) data available from EPPO (European and Mediterranean Plant Protection Organization) (...)”.

Q10. Please check the typographical errors and grammatical errors throughout the manuscript.

R10. The entire manuscript was carefully revised, and typographical and grammatical errors were corrected throughout the document.

Reviewer 4 Report (New Reviewer)

Comments and Suggestions for Authors

The author conducted a review on "Rice Pests and Diseases Around the World: A Literature-Based Assessment," which is meaningful and visually appealing, but there are some issues that need to be addressed.

 

The introduction is overly lengthy. There is a significant amount of content in lines 79-144 that discusses insects and diseases, which largely repeats the later findings in the results section. The author should have been more concise in introducing the background to allow the reader to grasp the context more quickly.

 

Lines 51-53 are somewhat unclear in relation to the topic. "Rice production occurs under different agricultural systems, often determined by the surface-water regime" .  how does this relate to the author’s focus?

 

The author includes considerable historical and geographical information, but does not explore whether there is a relationship between rice production levels in different regions and the prevalence of pests and diseases. Additionally, there is a lot of descriptive content about pests, but the specific impacts on rice yield losses are not sufficiently detailed.

 

Why didn’t the author focus on the specific impact of pests and diseases on rice yield in the introduction? The significance of this research should have been emphasized, particularly how these factors affect productivity. Although there are some related descriptions, they are somewhat diluted by the heavy focus on general descriptions.

 

The author did not differentiate Oryza sativa into its subspecies, such as Japonica and Indica, which are significantly different in terms of pest and disease resistance, among other traits.

 

Lines 367-368, “one viral genus (Sobemovirus) was reported to cause yield loss of up to 100%,” r Is a 100% yield loss really possible? Is this based on field studies or laboratory data? Can such total crop loss actually happen under field conditions? The author should clarify whether this is an experimental extreme or a field observation.

 

Figure 7, the author should consider the differences in data volumes between Africa and Asia, as this could lead to visual misinterpretation. The figure legend should clarify that the lack of data from Africa could cause the misconception that only leaves are affected.

 

Many of the findings are based on historical data, but the recent research trends are not sufficiently discussed. The author should integrate and consider recent developments in pest and disease research, along with emerging trends.

 

The author did not consider discussing the synergistic effects between pests and diseases, which is a very common phenomenon in plant pest and disease interactions. This is a crucial aspect that could offer valuable insights.

Author Response

Reviewer 4 comments

The author conducted a review on "Rice Pests and Diseases Around the World: A Literature-Based Assessment," which is meaningful and visually appealing, but there are some issues that need to be addressed.

Specific comments

Q1. The introduction is overly lengthy. There is a significant amount of content in lines 79-144 that discusses insects and diseases, which largely repeats the later findings in the results section. The author should have been more concise in introducing the background to allow the reader to grasp the context more quickly.

R1. Thank you for your suggestion on concising the introduction to a more context focused approach. The Introduction has been rewritten with a special attention to the section on pests and diseases, which can now be read as follows (L72-110):

“While the biotic network naturally controls most rice pests, a small number of insect species consistently pose a significant threat. According to Heinrichs and Muniappan [5], only 20 species in tropical Asia, 15 in Africa, and 20 in the Americas are of major economic importance, categorized as root and stem feeders, stem borers, gall midges, hoppers, foliage feeders, and panicle feeders. These pests, along with various diseases, can cause severe yield losses worldwide, sometimes reaching up to 60% [19].

Rice production is particularly affected by stem borers, hoppers, and defoliators. A meta-analysis on yield impacts caused by a complex of stem borers in Asia found that a 1% increase in whiteheads corresponds to a 4% reduction in yield [20]. In this country, major stem borers include Scirpophaga incertulas, which can cause yield losses ranging from 3 to 95% in India [21], and Chilo suppressalis [22]. In West Africa, key species such as Diopsis macrophthalma, Maliarpha separatella, Chilo zacconius, and Sesamia calamistis pose significant threats [5]. Additionally, rice gall midges (Orseolia spp.) affect rice production in both Asia and West Africa [19]. Hoppers, including leafhoppers (Cicadellidae) and planthoppers (Delphacidae), not only cause direct feeding damage but also serve as a vector for viral diseases such as rice tungro, Rice Transitory Yellowing, ‘hoja blanca’ virus, and Rice Yellow Mottle Virus (RYMV) [23-25]. Defoliators such as rice leaffolders (Cnaphalocrocis spp.), armyworms (Mythimna separata, Spodoptera frugiperda), and swarming caterpillars (Spodoptera mauritia) significantly reduce photosynthesis and damage panicles [5]. Additionally, coleopteran pests, including African hispids and flea beetles, serve as vectors of RYMV [5]. Although numerous insect species attack rice, only a subset inflicts severe economic losses, highlighting the need for effective pest management strategies.

Rice diseases, caused by fungi, bacteria, viruses, and nematodes, affect various plant parts and significantly impact yields [26]. Among fungal pathogens, rice Blast (Pyricularia oryzae) is the most destructive globally, affecting all growth stages and manifesting as leaf blast, neck rot, and panicle blast [5,27,28]. Bacterial Blight (Xanthomonas oryzae pv. oryzae) is the most severe bacterial disease, widespread except in Europe [29]. While viral diseases generally cause minor losses, outbreaks can be devastating. In Asia, Rice Tungro Spherical virus (RTSV) and Rice Grassy Stunt virus are major threats [30,31], ‘hoja blanca’ dominates in the Americas [23], and RYMV is the primary rice virus in Africa [32]. Nematodes also pose serious risks. The rice stem nematode (Ditylenchus angustus) causes Ufra disease, leading to 20%–90% yield losses in Asia. The root-knot nematode (Meloidogyne graminicola), widespread in flooded conditions, can result in up to 80% losses in upland rice and 73% in irrigated systems. Other damaging species include the white tip nematode (Aphelenchoides besseyi), and rice cyst nematodes (Heterodera spp.) [33]. Managing these pests and diseases is critical for ensuring stable rice production and food security.”.

Q2. Lines 51-53 are somewhat unclear in relation to the topic. "Rice production occurs under different agricultural systems, often determined by the surface-water regime".  how does this relate to the author’s focus?

R2. Thank you for your comment. This sentence aims to highlight the lack of research on specific agricultural rice production systems dependent on surface-water regimes, as is the mangrove rice system, where Oryza glaberrima rice species is predominant. This rice production system, somewhat overlooked and understudied, has unique water conditions (high salinity level, tides influence) affecting pest and disease dynamics. This gap suggests underrepresentation of certain production systems in research, hence the relevance of mentioning the different agricultural systems at the Introduction. To clarify this information, the sentence was revised and can now be read as follows (L58-66): “Rice production occurs under different agricultural systems, often determined by the surface-water regimes. These include dryland systems (upland or slash-and-burn) and wetland systems (freshwater swamps, deepwater/ mangrove swamps, and irrigated wetland) [7,14]. Mangrove swamp rice, a unique system found in West Africa, covers approximately 200 000 ha, primarily in Guinea-Bissau, Guinea Conakry, Senegal, Gambia, and Sierra Leone [15-16]. This farming system plays a crucial role in food security along the West African coast, contributing to more than 30% of the population’s caloric intake [17].”.

Q3. The author includes considerable historical and geographical information, but does not explore whether there is a relationship between rice production levels in different regions and the prevalence of pests and diseases. Additionally, there is a lot of descriptive content about pests, but the specific impacts on rice yield losses are not sufficiently detailed.

R3. Most studies mention yield losses in a qualitative rather than quantitative way. Even when quantitative % values are presented, the range is usually relatively large and varies from study to study. Nonetheless, the Introduction section has been rewritten and concised, with a special attention on the section on pests and diseases, with a note concerning to yield losses, which can now be read as follows (L72-110):

“While the biotic network naturally controls most rice pests, a small number of insect species consistently pose a significant threat. According to Heinrichs and Muniappan [5], only 20 species in tropical Asia, 15 in Africa, and 20 in the Americas are of major economic importance, categorized as root and stem feeders, stem borers, gall midges, hoppers, foliage feeders, and panicle feeders. These pests, along with various diseases, can cause severe yield losses worldwide, sometimes reaching up to 60% [19].

Rice production is particularly affected by stem borers, hoppers, and defoliators. A meta-analysis on yield impacts caused by a complex of stem borers in Asia found that a 1% increase in whiteheads corresponds to a 4% reduction in yield [20]. In this country, major stem borers include Scirpophaga incertulas, which can cause yield losses ranging from 3 to 95% in India [21], and Chilo suppressalis [22]. In West Africa, key species such as Diopsis macrophthalma, Maliarpha separatella, Chilo zacconius, and Sesamia calamistis pose significant threats [5]. Additionally, rice gall midges (Orseolia spp.) affect rice production in both Asia and West Africa [19]. Hoppers, including leafhoppers (Cicadellidae) and planthoppers (Delphacidae), not only cause direct feeding damage but also serve as a vector for viral diseases such as rice tungro, Rice Transitory Yellowing, ‘hoja blanca’ virus, and Rice Yellow Mottle Virus (RYMV) [23-25]. Defoliators such as rice leaffolders (Cnaphalocrocis spp.), armyworms (Mythimna separata, Spodoptera frugiperda), and swarming caterpillars (Spodoptera mauritia) significantly reduce photosynthesis and damage panicles [5]. Additionally, coleopteran pests, including African hispids and flea beetles, serve as vectors of RYMV [5]. Although numerous insect species attack rice, only a subset inflicts severe economic losses, highlighting the need for effective pest management strategies.

Rice diseases, caused by fungi, bacteria, viruses, and nematodes, affect various plant parts and significantly impact yields [26]. Among fungal pathogens, rice Blast (Pyricularia oryzae) is the most destructive globally, affecting all growth stages and manifesting as leaf blast, neck rot, and panicle blast [5,27,28]. Bacterial Blight (Xanthomonas oryzae pv. oryzae) is the most severe bacterial disease, widespread except in Europe [29]. While viral diseases generally cause minor losses, outbreaks can be devastating. In Asia, Rice Tungro Spherical virus (RTSV) and Rice Grassy Stunt virus are major threats [30,31], ‘hoja blanca’ dominates in the Americas [23], and RYMV is the primary rice virus in Africa [32]. Nematodes also pose serious risks. The rice stem nematode (Ditylenchus angustus) causes Ufra disease, leading to 20%–90% yield losses in Asia. The root-knot nematode (Meloidogyne graminicola), widespread in flooded conditions, can result in up to 80% losses in upland rice and 73% in irrigated systems. Other damaging species include the white tip nematode (Aphelenchoides besseyi), and rice cyst nematodes (Heterodera spp.) [33]. Managing these pests and diseases is critical for ensuring stable rice production and food security.”.

Q4. Why didn’t the author focus on the specific impact of pests and diseases on rice yield in the introduction? The significance of this research should have been emphasized, particularly how these factors affect productivity. Although there are some related descriptions, they are somewhat diluted by the heavy focus on general descriptions.

R4. Thank you for your comment. The introduction was significantly revised to be more concise by removing general descriptions that were overlength (suggested by Reviewer 1), where specific impacts of pests and diseases on rice yields were included, as per reviewer suggestion. Thus, the revised text can now be read as follows at (L79-95): “Rice production is particularly affected by stem borers, hoppers, and defoliators. A meta-analysis on yield impacts caused by a complex of stem borers in Asia found that a 1% increase in whiteheads corresponds to a 4% reduction in yield [20]. In this country, major stem borers include Scirpophaga incertulas, which can cause yield losses ranging from 3 to 95% in India [21], and Chilo suppressalis [22]. In West Africa, key species such as Diopsis macrophthalma, Maliarpha separatella, Chilo zacconius, and Sesamia calamistis pose significant threats [5]. Additionally, rice gall midges (Orseolia spp.) affect rice production in both Asia and West Africa [19]. Hoppers, including leafhoppers (Cicadellidae) and planthoppers (Delphacidae), not only cause direct feeding damage but also serve as a vector for viral diseases such as rice tungro, Rice Transitory Yellowing, ‘hoja blanca’ virus, and Rice Yellow Mottle Virus (RYMV) [23-25]. Defoliators such as rice leaffolders (Cnaphalocrocis spp.), armyworms (Mythimna separata, Spodoptera frugiperda), and swarming caterpillars (Spodoptera mauritia) significantly reduce photosynthesis and damage panicles [5]. Additionally, coleopteran pests, including African hispids and flea beetles, serve as vectors of RYMV [5]. Although numerous insect species attack rice, only a subset inflicts severe economic losses, highlighting the need for effective pest management strategies.”.

Q5. The author did not differentiate Oryza sativa into its subspecies, such as Japonica and Indica, which are significantly different in terms of pest and disease resistance, among other traits.

R5. Regarding the reviewer comment, most of the articles included in this study do not specify the rice subspecies. Additionally, our study did not account for the susceptibility or tolerance of rice species to pests and diseases, as this fell outside the inclusion criteria. Consequently, although relevant, the focus remains on rice species rather than subspecies, covering only Oryza sativa (Asian rice) and Oryza glaberrima (African rice). Including subspecies would require additional keywords across the three databases, leading to a broader dataset beyond the study’s initial objective: pests and diseases in the two rice species in the globe. However, this topic remains valuable for future research, not only applied to subspecies but also to rice varieties. To acknowledge this, a sentence was added to the conclusions, which states (L723-728): “While this study focused only on the two rice species, O. sativa and O. glaberrima, future research could broaden this scope by investigating the interactions between rice subspecies and varieties with pests and diseases, providing valuable insights into their susceptibility and resistance. This could help refine breeding programs, improve pest management strategies, and enhance global food security in the face of evolving climate conditions.”.

Q6. Lines 367-368, “one viral genus (Sobemovirus) was reported to cause yield loss of up to 100%,” r Is a 100% yield loss really possible? Is this based on field studies or laboratory data? Can such total crop loss actually happen under field conditions? The author should clarify whether this is an experimental extreme or a field observation.

R6. Thank you for your comment. The Sobemovirus is on the most devastating virus affecting rice in Africa, and many reports (in controlled and field studies) highlight that rice yield losses fluctuate between 10% and 100% (highly variable), which may be dependent on several factors as on plant age prior to infection, susceptibility of rice variety, and environmental factors. To accommodate this reality, a new sentence was added at discussion section at L625-629: “Nevertheless, it is important to note that while many yield losses studies are conducted in controlled environments, field studies conditions are far more complex, with various abiotic, chemical, geological, and biotic factors interacting, making yield loss highly variable and potentially influenced by multiple, less evident organisms, or other factors.”; and at L640-643: “However, rice yield losses to RYMV have been reported to fluctuate highly between 10% and 100%, depending on plant age prior to infection, susceptibility of rice variety, and environmental factors, both in experimental and field assays.”.

Q7. Figure 7, the author should consider the differences in data volumes between Africa and Asia, as this could lead to visual misinterpretation. The figure legend should clarify that the lack of data from Africa could cause the misconception that only leaves are affected.

R7. The authors would like to thank the reviewer's suggestion. Both Figure 7 and its caption were restructured, and the data volumes are now presented proportionally according to data volumes for each region (Africa and Asia). The new caption can now be read as follows at L478-480: “Schematic representation of rice plant parts affected by each disease across continents (Africa vs. Asia) based on available data. Link widths are proportional to the number of records.”.

Q8. Many of the findings are based on historical data, but the recent research trends are not sufficiently discussed. The author should integrate and consider recent developments in pest and disease research, along with emerging trends.

R8. Thank you for the suggestion. Considering the reviewer comment, new information was included at the Discussion section by integrating research developments on pests and diseases, namely cultural practices, genetic resistance, etc. The revised text reads as follows (L680-692): “Effective rice disease management maximizes yields, ensures food security, and supports sustainable farming. Key strategies include genetic resistance breeding, biological control, cultural practices, and responsible chemical use. Advances in molecular breeding have led to the development of resistant rice varieties against major diseases like rice Blast [100] and Bacterial Leaf Blight [101]. Biological control using microorganisms like Pseudomonas fluorescens, which demonstrate antagonistic effects against pathogens such as Bipolaris oryzae, reduces reliance on chemical pesticides [102]. Cultural practices such as integrated pest and disease management (IPM and IDM, respectively), water regulation, and crop rotation have been shown to reduce disease incidence [103-104]. Additionally, farmer education plays a key role in strengthening these efforts. Technology-driven methods, like predictive modelling, aid early detection [105], reducing yield losses. A holistic approach integrating these strategies strengthens rice production and sustainability.”

Q9. The author did not consider discussing the synergistic effects between pests and diseases, which is a very common phenomenon in plant pest and disease interactions. This is a crucial aspect that could offer valuable insights.

R9. The authors would like to acknowledge the reviewer's valuable suggestion on considering the important synergistic effects between pests and diseases. To accommodate this topic, a new paragraph was added at L693-702: “As a final consideration, in rice ecosystems, pests and diseases often interact synergistically, resulting in greater damage than their individual effects [106]. This interaction accelerates crop loss, reduces yields, and complicates management strategies. Primary pests directly reduce productivity, while secondary pests, such as stem borers [57], weaken plants and increase their susceptibility to disease. Stem borers create entry wounds that allow fungal pathogens to infect rice, weakening stems and attracting more pests. For instance, Sheath Root incidence rises with plant density and insect damage, particularly at the panicle initiation stage, leading to upper leaf sheath rot and stunted panicle emergence [107]. Additionally, rice-fish polyculture [108-109] may help reduce insect pests and diseases in rice fields [110], potentially mitigating these synergistic effects.”.

Round 2

Reviewer 1 Report (New Reviewer)

Comments and Suggestions for Authors

The authors adequately addressed the suggested revision.

Reviewer 4 Report (New Reviewer)

Comments and Suggestions for Authors

The authors have answered my question, and I have no other comments.

This manuscript is a resubmission of an earlier submission. The following is a list of the peer review reports and author responses from that submission.

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

The MS entitled with “Global Assessment of Rice Pests and Diseases: A Systematic Review on the Identification, Distribution and Productivity Constraints” showed a comprehensive overview on the rice pest and disease around the world. It will contribute to the global understanding of rice pests and diseases distribution patterns and evaluate their impacts on rice productivity. I suggest a “major revision” before its publication. The main comments are as follows:

 

1.     The main concern of this study is that it seemed the conclusion get from the analysis is well-known. Is there any new conclusion could be come out?

2.     What is the key words when search these articles? It should be described in the PRISMA flow. And what is the excluded criterion in the screening? Is there any references?

3.     Why choose these four main subjects “Pests, Diseases, Pests & Diseases, and Predators” in data curation workflow?

4.     The resolution ratio of these figures is too low, it could not be seen clearly.

Comments on the Quality of English Language

no

Author Response

Q1. The MS entitled with “Global Assessment of Rice Pests and Diseases: A Systematic Review on the Identification, Distribution and Productivity Constraints” showed a comprehensive overview on the rice pest and disease around the world. It will contribute to the global understanding of rice pests and diseases distribution patterns and evaluate their impacts on rice productivity. I suggest a “major revision” before its publication. The main comments are as follows:

R1. The authors would like to acknowledge the comments of the reviewer, which have been addressed accordingly and point-by-point responses are provided below.

Specific comments

Q2. The main concern of this study is that it seemed the conclusion get from the analysis is well-known. Is there any new conclusion could be come out?

R2. The authors would like to acknowledge the reviewer for the comment to include new conclusion, which has been rewritten in the revised manuscript at L598-L617, and read as follows: “This systematic review summarizes global knowledge on rice pests and diseases, highlighting key threats in Africa and Asia. In Africa, the top pests are stem borers (Diopsis spp., Maliarpha separatella, Chilo zacconius), which cause stem damage leading to white panicles and reduced grain quality. In Asia, major pests include stem borers (Scirpophaga incertulas, Chilo suppressalis, Sesamia inferens) and sap-sucking pests like plant- and leafhoppers (e.g., Nilaparvata lugens), which transmit viruses (e.g., Nilaparvata lugens, the vector of Rice Grassy Stunt Virus and Rice Ragged Stunt Virus) and directly damage the plants. Moreover, this study highlights that the leaf is the most affected tissue by both pests and diseases, often leading to secondary damage in other parts of the plant. Most research is biased toward Asia, particularly India, China, and the Philippines, leaving a substantial gap in knowledge concerning African rice production. Moreover, there is a need to increase our knowledge about field pests and diseases of African and Asian rice that can also cause storage losses or human health problems (see [103] for the case of disease-causing fungi). Future studies should aim to expand our understanding of pest and disease dynamics, particularly in Oryza glaberrima in African rice ecosystems. Through the interdisciplinary approach employed in this review, a comprehensive perspective on the biotic challenges faced by rice producers was provided. Such studies will help bridge existing knowledge gaps and support the development of more effective pest and disease management strategies, especially in under-researched regions like African rice producing countries.”

 

Q3. What is the key words when search these articles? It should be described in the PRISMA flow. And what is the excluded criterion in the screening? Is there any references?

R3. Thank you for pointing out this subject. The keywords, together with searched Boolean operators used according to each database, are described at supplementary Table S1, however, to address the reviewer comment, and to clarify the set of keywords selected in the study, we have included new text at the Material and Methods section, sub-section 2.1, as follows (L151- L175): “Following the PRISMA guidelines [31], a set of specific keywords combination were searched according to four search queries: i) rice pests and diseases characterization in the world (keywords applied: ‘oryza sativa’ AND ‘disease’; ‘oryza sativa’ AND ‘pest’; ‘oryza glaberrima’ AND ‘disease’; ‘oryza glaberrima’ AND ‘pest’; ‘rice’ AND ‘disease’; ‘rice’ AND ‘pest’); ii) rice pests and diseases characterization in Africa (keywords applied: ‘oryza sativa’ AND ‘africa’; ‘oryza glaberrima’ AND ‘africa’; ‘oryza sativa’ AND ‘africa’ AND ‘disease’; ‘oryza sativa’ AND ‘africa’ AND ‘pest’; ‘oryza glaberrima’ AND ‘africa’ AND ‘disease’; ‘oryza glaberrima’ AND ‘africa’ AND ‘pest’; ‘rice’ AND ‘africa’; ‘rice’ AND ‘africa’ AND ‘disease’; ‘rice’ AND ‘africa’ AND ‘pest’); iii) rice pests and diseases characterization in west africa (keywords applied: ‘oryza sativa’ AND ‘west africa’; ‘oryza glaberrima’ AND ‘west africa’; ‘oryza sativa’ AND ‘west africa’ AND ‘disease’; ‘oryza sativa’ AND ‘west africa’ AND ‘pest’; ‘oryza glaberrima’ AND ‘west africa’ AND ‘disease’; ‘oryza glaberrima’ AND ‘west africa’ AND ‘pest’; ‘rice’ AND ‘west africa’; ‘rice’ AND ‘west africa’ AND ‘disease’; ‘rice’ AND ‘west africa’ AND ‘pest’); iv) characterization of mangrove rice pests and diseases - from world to west africa (the main rice producing region within mangrove agroecosystem and the pivotal region of African rice - Oryza glaberrima - production) (keywords applied: ‘mangrove rice’ AND ‘disease’; ‘mangrove rice’ AND ‘pest’; ‘mangrove rice’ AND ‘africa’ AND ‘disease’; ‘mangrove rice’ AND ‘africa’ AND ‘pest’; ‘mangrove rice’ AND ‘west africa’ AND ‘disease’; ‘mangrove rice’ AND ‘west africa’ AND ‘pest’; ‘mangrove rice’; ‘mangrove rice’ AND ‘africa’; ‘mangrove rice’ AND ‘west africa’). The complete keywords combination as well as Boolean operators applied to each bibliographic database is detailed at Table S1. To cover the largest number of studies in the data search, all publications were considered, regardless of written language, availability of the full text, or type of publication (e.g., review).”

Regarding the exclusion criteria, which are described in L190-196 at the Material and Methods Section, two exclusion criteria have been applied in the curation of articles retrieved from the three databases: the first involved the manual curation of articles by title only, which did not fitted the exact keywords applied, and read as follows on the manuscript at L190-L194: “Articles were then excluded by applying the 1st exclusion criterion: manual curation (by title) of records not directly related to the subject, including at least one of the four disciplines: medical/ veterinary and biotechnology; molecular biology/ resistances/ tolerances of rice varieties; agricultural practices/ farmer perceptions; other crops.”; the second exclusion criteria involved a thorough analysis of all remaining articles by reading the full text or abstract, when full text was not available, and determine if its content meet the search queries under analysis. The second exclusion criterium is described at the Material and Methods section in L194-L196, and reads as follows: “To the remaining records was applied the 2^nd criterion: manual curation (by full article or abstract, whenever the full article was not available) of records not directly related to the subject, including the same disciples as the 1^st criterion.”.      

When performing a systematic review, both inclusion and exclusion criteria set the boundaries for the systematic review itself, by determining after setting the research topics usually before the search is conducted, however scoping searches may need to be undertaken to determine appropriate criteria. Following Page et al. (2021), on the PRISMA 2020 explanation and elaboration: updated guidance and exemplars for reporting systematic reviews (BMJ 2021; 372 https://doi.org/10.1136/bmj.n160), the specification of the exclusion (or inclusion) criteria for the review and how studies were grouped for synthesis to determine articles eligibility is usually recorded as a paragraph or table within the methods section of the systematic review.  Exclusion criteria are defined case-by-case, based on the research queries defined by the authors, and thus no specific reference was cited. As per PRISMA rules and following Page et al (2021), the specification of exclusion criteria applied has been defined as a paragraph (L190-L196), and has been included in the PRISMA workflow diagram as well as keywords used, as per reviewer suggestion, in the new Figure 1 (L203) of the revised version of the manuscript.

Q4. Why choose these four main subjects “Pests, Diseases, Pests & Diseases, and Predators” in data curation workflow?

R4. Thank you for your question. The main aim of this work is to provide a comprehensive summary of the top pests and diseases affecting rice globally, therefore, keywords applied were targeted to this objective. Nevertheless, after applying the eligibility assessment for final articles list, the articles retrieved were grouped for organization purposes for results analysis. Thus, by grouping articles according to the subject on Pests, Diseases, Pests & Diseases and Predators, allowed to provide a clear overview for extracting relevant information for results analysis.

Q5. The resolution ratio of these figures is too low, it could not be seen clearly.

R5. Thank you for highlighting this issue. In the revised version, new high-resolution figures have been uploaded to the manuscript.

Reviewer 2 Report

Comments and Suggestions for Authors

I have read the manuscript 'global assessment of rice pests and diseases:....' and find that the authors conducted a very large trawl of document to determined prevalence of pests and diseases in the literature and relevance to different countries and continents, and plant parts. The paper is succinct given the topic, the writing is generally good and the analyses of information somewhat innovative. Unfortunately, the article is weak in a number of areas. Firstly, the title is somewhat misleading because the paper is more directly related to the bibliography that a true analyses of pest and disease incidence and effects. The latter requires some more accurate dating and mapping, some assessment of underlying causes, a greater critical assessment of information sources, and in particular, some critical information on damage, yield losses or profitability losses. Therefore, the title needs to be changed to better reflect the limitations of the work. The paper is not a strong assessment of identity or distribution, and does not assess productivity losses. The assessment seems to be based on a rapid scanning of article titles and abstracts. This is apparent in the lack of any information on the dynamics of pest/disease occurrence, underlying causes, secondary links to management methods, updating of taxonomy, etc.. The authors have not critically assessed methodologies or analyses in the reviewed papers. This is particularly important when referring to yield losses. Some authors may exaggerate losses because they are drawn to research unusual pest/disease conditions, such as outbreaks. The yield loss information should therefore be contextualized. Overall, the paper is superficial as a review, but adequate as a bibliographic assessment - although the authors have excluded a very large number of potentially useful articles - such as articles related to host resistance/tolerance, which likely includes useful distribution and incidence data. Some minor issues that should be corrected include - excessive summarizing of a single article (reference 5), particularly in the introduction - therefore, under referencing of large sections, some misspelling of scientific names, or the need to update taxonomic information (79-82); unbalanced search because of an emphasis on W. Africa that will distort coverage indicators. Mention/graphing of first mention in literature is interesting, but the frequency of mention over time is more useful.

Author Response

Q1. I have read the manuscript 'global assessment of rice pests and diseases:....' and find that the authors conducted a very large trawl of document to determined prevalence of pests and diseases in the literature and relevance to different countries and continents, and plant parts. The paper is succinct given the topic, the writing is generally good and the analyses of information somewhat innovative. Unfortunately, the article is weak in a number of areas.

R1. The authors would like to acknowledge the comments of the reviewer to the manuscript. For better understanding, the reviewer's comments were divided into sections with point-by-point responses.

 

Specific comments

Q2. Firstly, the title is somewhat misleading because the paper is more directly related to the bibliography that a true analyses of pest and disease incidence and effects. The latter requires some more accurate dating and mapping, some assessment of underlying causes, a greater critical assessment of information sources, and in particular, some critical information on damage, yield losses or profitability losses. Therefore, the title needs to be changed to better reflect the limitations of the work.

R2. The authors thank the reviewer for raising this issue, which we agree. As such, as per reviewer suggestion the Title has been modified to “Rice Pests and Diseases Assessment at Global Scale: A Systematic Review”.

Q3. The paper is not a strong assessment of identity or distribution, and does not assess productivity losses. The assessment seems to be based on a rapid scanning of article titles and abstracts. This is apparent in the lack of any information on the dynamics of pest/disease occurrence, underlying causes, secondary links to management methods, updating of taxonomy, etc.. The authors have not critically assessed methodologies or analyses in the reviewed papers. This is particularly important when referring to yield losses. Some authors may exaggerate losses because they are drawn to research unusual pest/disease conditions, such as outbreaks. The yield loss information should therefore be contextualized.

R3. Thank you for your comments. We agree that the dynamics of pests and diseases involve different features not covered by our study. Nevertheless, the study conducted aims to fill a gap knowledge on the past and current status of rice pests and diseases, its identification and distribution trends across major rice producing regions. Considering the study covers both pests and diseases on rice globally through a screening of articles in three databases, curation of data retrieved as well as its analysis reflects an overall great amount of work. Regardless, our work did not cover additional subjects that could, and are important, in terms of pests and diseases production losses, namely methodologies or analyses on yield losses assessment. The yield losses included in the results analysis were retrieved for an overall assessment of the reported production losses described in the articles eligible for analyses, and considering that some authors may exaggerate losses, we considered presenting ranges instead of specific values ​​for each disease. We agree with the reviewer that “Some authors may exaggerate losses because they are drawn to research unusual pest/disease conditions (…)” and, following reviewer suggestion, we have included a new text to clarify and contextualize the yield loss information used for results analysis, at L224-L229: “To analyse the estimated yield losses for each disease, the maximum percentage values reported in the studies for the top disease agents (bacteria, fungi, and viruses) were considered. Despite being aware of the potential bias of yield losses reported by each article, related to both methodologies and analyses, the reported values were represented as yield losses intervals using box plot graphs. These graphs were generated using the ‘graphics’ package and the ‘boxplot’ function in R software v. 4.2.3 [34].”.

Q4. Overall, the paper is superficial as a review, but adequate as a bibliographic assessment - although the authors have excluded a very large number of potentially useful articles - such as articles related to host resistance/tolerance, which likely includes useful distribution and incidence data.

R4. Thank you for your comments and the authors agree (and are aware) that potential loss of data have occurred when excluding certain topics, such as resistance and tolerance, that would be potentially interesting to uncover if any resistance/tolerance to a pest and/or disease have been reported. However important, such inclusion would imply a whole new area of ​​analysis that goes beyond the objectives of our study.

Q5. Some minor issues that should be corrected include - excessive summarizing of a single article (reference 5), particularly in the introduction - therefore, under referencing of large sections, some misspelling of scientific names, or the need to update taxonomic information (79-82); unbalanced search because of an emphasis on W. Africa that will distort coverage indicators. Mention/graphing of first mention in literature is interesting, but the frequency of mention over time is more useful.

R5. Thank you for pointing out important corrections on the manuscript. At the revised version of the manuscript, the Introduction was revised, and the references citation improved, as per reviewer suggestion, by adding new and appropriate references. Following reviewers’ comment, the misspelling of scientific names has been carefully revised throughout the manuscript to correct any errors and ensure that the most up-to-date taxonomic information was used (e.g. L103; L128).

Regarding the comment raised on West Africa emphasis, we recognize that the specific focus on this region may result in an unbalance in geographic coverage, however its inclusion was essentially made to cover the main African rice producing region as well as the specific mangrove rice agroecosystem, which is a very understudied rice producing system. To accommodate the comment made by the reviewer, new text was included to clarify the highlighting of West Africa coverage in our study, at the Introduction at L132-134: “(…) world, with a significant lack of knowledge on the main African rice producing regions, particularly West Africa.”; Methods at L165- L167: “iv) characterization of mangrove rice pests and diseases - from world to west africa (the main rice producing region within mangrove agroecosystem and the pivotal region of African rice - Oryza glaberrima - production)”; as well at the Discussion section (L385-394) "The review highlighted some shortcomings, such as the scarcity of articles from African rice producing countries and the very few applied to Oryza glaberrima species. The scarcity on O. glaberrima information can be verified with the available information on pests and diseases found in EPPO [42], which presents a total of 2 pests (Nilaparvata lugens and Orseolia oryzae) and 3 diseases (Xanthomonas oryzae pv. oryzae, X. oryzae pv. oryzicola, and Rice Yellow Mottle Virus). This lack of information can be understood by the fact that O. glaberrima production is almost restricted to West Africa, where research efforts are scarce [43-44]. On the contrary, for O. sativa, EPPO lists about 70 pests (including 2 snails) and 44 diseases (including 10 nematodes)."

Regarding the comment “mentioning /graphing on first mention of a pest and/or disease from the literature”, the authors sought to reconstruct the overall assessment of a first report of a specific disease/pest, rather than providing each disease/pest expansion over time, despite its usefulness. Considering the number of pests and diseases included in our study, providing a complete frequency assessment over time, would result in a high number of graphs, since at the text several information is provided upon its mentioning over time (e.g. L470-480: “Known to have been present since 1828 in Japan [63], Bakanae is a seed-borne disease that can cause infection at any stage of the crop’s life, from pre-emergence to maturation, leading to withering or poor germination of rice seeds [62]. With 32% of the Asian records of Bakanae disease originating in India, its first mention belongs to Japan in 1928 [64]. Interestingly, ‘bakanae’ is a Japanese term that means ‘bad’ seedling, referring to the infrequent early seedling elongation caused by the production of mycotoxin (gibberellin) during the infection cycle [62]. A study recorded the disease in China, using samples of rice seedlings with symptoms of Bakanae disease collected between 1977 and 1987 [65]. In the first decade of the millennium, it was recorded in Indonesia and Malaysia [66-67]. Its mention in India only occurred in 2013 [68] and has been consistently recorded in several Asian countries until the present year.”).

Round 2

Reviewer 2 Report

Comments and Suggestions for Authors

I have now read through the revised article and believe that the authors have not sufficiently addressed my previous comments. R2 - the title change should not include systematic review but bibliographic assessment/description; R3 - authors prefer to not draw any further insights from the reviewed literature; R4 - the main comment was again about bibliography, but authors focused their response on resistance/tolerance; R4 - some justification was given regarding mangroves and Africa.

My main concern after my first review was that the paper did not constitute a systematic review, but rather a description of bibliography. To improve the paper it was suggested that the authors could rewrite the paper as a bibliography, or would otherwise need to inject some critique of literature, gained insights or novelty into the systematic review. The previous version of the manuscript gave the impression that the authors superficially assessed articles for geographic region, pest/disease species, plant parts affected by diseases, dates of first mention and other themes of relatively minor interest; the new manuscript has not improved sufficiently to suggest that it is no longer superficial.

The authors demonstrate a lack of expertise in the topic of the review which erodes credibility. For example, many of the scientific names of pests are incorrect, practically all information regarding yield losses is uncritical, and many claims are exaggerated (i.e., the methods are not interdisciplinary, the paper does not indicate species distributions but country records; it is likely incorrect on first years of mention because older synonyms were not included); furthermore, the review is completely unbalanced: it has very little information on Europe, Australia or the Americas and has more information on diseases than pests; it is highly repetitive; and it brings little in the way of novel information or informed conclusions.

I would encourage the authors to think how they might produce an interesting manuscript from their hard work in retrieving and reading so many papers - perhaps by reducing their focus and going more in dept into specific topics. The writing style is generally good and some of the analyses are proficient.

I include some further observations below.

48 – why is this surprising? Asia has very large countries like China, India, Indonesia

71 Diopsis longicornis or syn. thoracica not macrophtalma

68-96 this paragraph is too long – better to split the in two with one about planthoppers

85 Cicadellis = ??

85 Recilia – Maiestas

90 Susamia = Marasmia

79 cubanus – orizicolus is the main vector (Morales and Jennings 2010) check the bibliography

137 what is interdisciplinary about this?

140 what does 'track' mean in this context

137-140 this sentence is very confusing

147-171 this could be compressed in several cases; i.e., Oryza and either a, b, c etc.

191 not in capitals

206-211 what use is maximum yield losses? There is no understanding of scale (authors could have been referring to caged rice plants - we are given no information), method, conditions, etc. – this should be very carefully considered because such information can drive pesticide use; if assessing yield losses is not carried out with care and systematically, then it is better not to include at all.

245-250 what is the difference between ‘do not present information’ and ‘are absent’. These sentences are unclear. I do see several papers on rice pests in Myanmar based on a google scholar search.

21 N. muiri is not a pest of rice

Figure 3 – Of the top pests, why not include the species names where ‘sp.’ is indicated (this figure is not necessary)

Figure 4 – these graphs are nice and represent the most interesting part of the work – but they are not indicators of distribution, but rather bibliographic interest related to countries.

Figure 5 – this figure is misleading because it does not include first mention under older taxonomies, for example, Sogatella furcifera has synonyms Sogata and Delphax, both of which have been mentioned in the 1960s as affecting rice; furthermore, the authority names for many species are from the 1800s. The figure really just presents the first mention under the currently used scientific names.

369-371 – what does this mean?