Seasonal Variation in Foliar Mite Diversity and Abundance in Leaf Domatia of Three Native South African Forest Species

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

The main comments and suggestions are in the pdf file.

In general, the authors must to think about the main objective of the work and develop a suitable methodology to test it. The current version of the manuscript fails to test and to answer which is the role of leaf domatia on seasonal variation of mite community because the methodology is not suitable. The current methodology does not allow to answer the role of domatia neither the difference between hosts, only to evaluate the dynamic of mite community in three plants with domatia, but not the effect of leaf domatia by itself.

Considering this, I suggest the author to revise and think about the main aim of the manuscript if they presume to keep the methodology, or to change the methodology in order to answer the objective.

Comments for author File: Comments.pdf

Comments on the Quality of English Language

It is recommended a basic style review 

Author Response

1. The main comments and suggestions are in the pdf file.

In general, the authors must think about the main objective of the work and develop a suitable methodology to test it. The current version of the manuscript fails to test and to answer which is the role of leaf domatia on the seasonal variation of the mite community because the methodology is not suitable. The current methodology does not allow to answer the role of domatia nor the difference between hosts, only to evaluate the dynamic of mite community in three plants with domatia, but not the effect of leaf domatia by itself.

Considering this, I suggest the author revise and think about the main aim of the manuscript if they presume to keep the methodology, or to change the methodology in order to answer the objective.

Re: We thank the reviewer for this and the comments in the pdf. We have thought about the above comment and have reworked this manuscript to be more about the issue of seasonality and less focused on the role of domatia. The domatia are perpetually present in mature leaves – but we are interested in the diversity and abundance of mites. One of the findings (Figures 5 & 7) suggests the mite diversity might be partially host-specific (and we allude to this in the text), and this is an interesting line of future research, to investigate the role of domatia

 

2. The abstract is generally clear, but some sentences are lengthy and could benefit from simplification for easier comprehension. The abstract lacks specific details about the methodology, such as the geographic location of the study, the duration of the investigation, and the specific analytical methods employed. Including this information would enhance the credibility and replicability of the study. The abstract mentions the correlation of mite abundance and diversity with environmental factors, but it doesn't provide specific correlation coefficients or statistical significance levels.

The authors did not explore the potential reasons for the inconsistencies in the results and discussing their implications would be valuable.

The hypothesis regarding the influence of leaf architecture and food availability are lacking, could be indicated more explicit connections between these factors and the observed variations in mite diversity and abundance.

The conclusions are not straightforward, and the last sentence is too wide and did show a robust contribution of the work to the studied subject. It must be reviewed.

Re: The has been revised to make the abstract more detailed and to improve the arguments made as suggested.

 

1. Does leaf domatia improve the survival rate of some mites during extreme weather conditions?

Re:  Yes, Leaf domatia are believed to affect the microclimate of leaves by maintaining favourable humidity levels creating suitable conditions for mites and preventing desiccation of their eggs during periods of extreme environmental conditions [3, 6, 17, 37] This benefit may be especially important in the inactive stages during moulting where mites may be vulnerable to physical extremes. Domatia also shield mites from ultraviolet radiation []36, 38].

 

3. Please add this reference to show the effects of temperature & RH on the population of Predatory mites. Jafari, S, Fathipour, Y., Bahirai, F. 2012. Population fluctuation of Neoseiulus barkeri (Acari: Phytoseiidae) and its prey, Tetranychus (Acari: Tetranychidae), in cucumber fields of Khorramabad, Iran. Journal of Entomological Society of Iran, 33(1): 1-11.

Re: We were not able to get the full version of this article and thus decided not to cite it. 

 

4. Cassava does not present leaf domatia. I don´t think the comparison is valid. Despite it is important to highlight some studies approaching seasonal variation of predatory mites, I don't see a clear link between the studies and the focus of this work.

Re: We included these findings because in the paragraph we discussed studies on mite seasonality in Africa and we did not allude that cassava has domatia. The emphasis is on studies conducted in Africa and that there are few studies have been conducted in the region. We have reworked this manuscript to be more about the issue of the seasonality of mites in African ecosystems.

 

5. would be very informative to present a figure showing all the three plants in general and each of their leaf domatia.

Re: I only have pictures of two of the three plants. Without the third picture, these two will not be informative. 

   

6. Only one individual is impossible to analyse the seasonal dynamic, due to the lack of independence of the samples (leaves)

Re: We believe the 20 leaves are independent samples because care was taken to collect the leaves all around the tree and far from each other. A leaf is an ecosystem for mites and mites rarely migrate long distances. 

7. I think the leaf cannot be considered the sample unit of the project, since they are not independent, even in a large tree.

Re:  We ask that the reviewer see the comment above where we have responded to this comment. 

8. Which comparisons were performed? between plants with and without domatia, between seasons, between plant species? This part is confusing, and I cannot see a clear relation with the main aim. Why the comparisons? what do the authors want to test?

Re: Comparisons were made between seasons and between the trees. This has been clarified in the manuscript.

I wanted to test whether there were differences in mite abundance and diversity between the seasons. I also want to test whether the seasonal were differences in mite abundance and diversity between the plants I sampled regardless of seasons.

 

9. In which season the abundance was higher? the same pattern was observed for all three species? The first and second paragraphs must be rewritten and restructured. I suggest authors show the general pattern first followed by the main findings of each host plant. More important than highlighting that there was a statistical difference is to indicate where the difference was observed, and where and when they found the higher and lower abundances.

Re:  Line 173 specifies that the mite abundance was highest in the spring and summer of 2014. The paragraphs have been restructured.

 

10. I strongly recommend using species richness instead of Shannon diversity index. Recently there has been some criticism about the use of Shannon or another diversity index. So, in this case is recommended to present the total abundance and species richness as community parameters.

Re: Given the time constraints, we are not able to do this. 

 

11. This mite is one of the oribatid mites, these mites are in the soil and the probability of it being on the plant leaf is very low. Please check it.

Re: The Siculobata sicula mite was collected only found in G. thunbergia ounce and only five were collected.   

 

12. Must be restructured. There was a repetition of the results, and I did not realize a clarification in many aspects highlighted by the authors.

Re: The discussion section has been restructured

 

13. the processes that explain the seasonality are too vague. I cannot see how the manuscript contributes directly to the direction, in terms of shed light on how seasonality, leaf domatia and other processes drive mite abundance throughout the year.

Re: Some studies [29, 30] which are cited in the manuscript have shown that leaf domatia and other processes drive mite abundance throughout the year. And we believe that this paper adds to that growing literature by showing that mites can survive inside domatia all year.  The study shows no correlation in mite abundance with rainfall which suggests that they were not affected by it, and we believe it is because they can hide inside the domatia.   

 

14. The conclusions fail in terms of indicating the real contribution of this work. Seems that there was not a concrete advance in this theme after the experiment. The authors must focus on understanding how the studied processes drive the mite community, and which is the pattern observed.

Re: have revised the conclusion.  

Reviewer 2 Report

Comments and Suggestions for Authors

Title: The role of leaf domatia on seasonal variation in foliar mite diversity and abundance in three native South African forest plant species

Authors: Sivu Situngu, Nigel Barker

Reviewer comments:

-The topic of manuscript is interesting. I found some merits in this study, however the article needs minor revision. Please see the attached pdf file. I put some comments in the main file of the article.

- Overall, different parts of the article were well written.

-Although in sampling protocol (In M&M), I suggest you explain in more detail. Usually to sampling you need a preliminary test and then according to that you have to determine the sampling size.

Did you have a preliminary test?  

- The main question is that are you sure you knew the mites alive on the plants for the unmounted counts? In lines 197-200 you wrote that “The most species of mites that were frequently encountered in the domatia of the trees were Neosuilus californicus (Phytoseiidae), Tydeus monsteri (Tadeidae), Bravipalpus sp. (Tenupalpidae), Typhlodomus microbullatus (Phytoseiidae), Tetratriophydeus myacanthus (Triophtydeidae).

While phytophagous mites have a very higher population compared to predatory mites even in domatia. Please explain this.

- I found mistakes in the scientific name of mites that should be corrected (see attached pdf file).

Best wishes

 

Comments for author File: Comments.pdf

Author Response

Reviewer no 2 

1. The topic of the manuscript is interesting. I found some merits in this study, however the article needs minor revision. Please see the attached pdf file. I put some comments in the main file of the article.

Re: We thank the reviewer for these comments on the pdf and have addressed them as best we can.

 

2. Although in sampling protocol (In M&M), I suggest you explain in more detail. Usually, to sampling you need a preliminary test and then according to that you must determine the sampling size.

Re: A preliminary test was conducted when we conducted another study on the distribution of mites on the tree canopy and we found that it was sufficient to collect 20 leaves. See [32]  

 

3. Did you have a preliminary test?

Re: Please see comment above. 

 

4. The main question is that are you sure you knew the mites alive on the plants for the unmounted counts? In lines 197-200 you wrote that “The most species of mites that were frequently encountered in the domatia of the trees were Neosuilus californicus (Phytoseiidae), Tydeus monsteri (Tadeidae), Bravipalpus sp. (Tenupalpidae), Typhlodomus microbullatus (Phytoseiidae), Tetratriophydeus myacanthus (Triophtydeidae).

 

Re: the mites were given code manes prior identification and all of them were collected and mounted on a glass slide. Thus, we were able to later identify them. 

5. I found mistakes in the scientific name of mites that should be corrected (see attached pdf file).

Re: These have been corrected.

Reviewer 3 Report

Comments and Suggestions for Authors

The manuscript presents results on population dynamics and species diversity of mites found in domatia of three tree species grown in South Africa. Data analysis revealed differences between tree species and various seasons as well as effects of some abiotic conditions. The manuscript is well written but there are some typos in species names. I also believe that the Results and/or Discussion should distinguish ecological groups of mites (phytophagous, fungivorous, predatory mites etc.). There are 41 references, most of them highly relevant to topic though some other more appropriate literature dealing with woody plants could be selected.

Specific comments (numbers indicate line numbers in ms):

25 I suggest to exclude/modify words which are already in title, e.g. acarodomatia; leaf morphology; abiotic conditions etc.

36-37 there might be one more function of domatia for predatory mites - they can provide also food, e.g. they collect pollen grains (c.f. https://doi.org/10.3390/f14050942)

48 "predation" might be better term than "parasitism", cannibalism is other possibility

58 typo: Typhlodromalus and no full stop after DeLeon

63, 64 and onwards, similarly no full stops after authors names

83 either Eriophyoid or Eriophyid

91 check geographical coordinates format

142 please write software version and reference or source

153 reference or name of producer with city and country

183 Mite density is per leaf but it shows only mites found in domatia so it would be also interesting how number of domatia per leaf differs between tree species (or also season which probably also affects leaf size). If these data are available, it would good to add them into Results.

198 typo Neoseiulus 

198 and onwards: add authors names to all species

199 typo Typhlodromus

202 species which names are mentioned for the first time in the manuscript should be written in full (i.e. with full genera name) and author names

215 Table - authors names at species should be consistent

218 Fig 5b typo Eriophyidae

279-280 Several papers documented that hairy leaves have much more mites complared to species with glabrous leaves (e.g. birch) - see papers by Tuovinen, Kabíček and others

287-288 linguistic corrections needed

292 typo Neoseiulus

296 typo Eriophyidae

 

Comments on the Quality of English Language

There are only some typos, also punctuation should be corrected.

Author Response

 

1. -25 I suggest excluding/modify words which are already in the title, e.g. acarodomatia; leaf morphology; abiotic conditions etc.

-36-37 There might be one more function of domatia for predatory mites - they can provide also food, e.g. they collect pollen grains (c.f. https://doi.org/10.3390/f14050942)

 Re: We thank the reviewer for alerting us to this study – we have incorporated it into the manuscript.>

 

2. -48 "predation" might be better term than "parasitism", cannibalism is other possibility

Re: we have modified the line as suggested.

 

3. -58 typo: Typhlodromalus and no full stop after DeLeon

Re: This has been corrected.

 

4. -63, 64 and onwards, similarly no full stops after authors names

Re: Corrected.

 

5. -83 either Eriophyoid or Eriophyid

Re: Eriophyoid is correct

6. -91 Check the geographical coordinates format.

Re: Thank you, the format has been corrected

 

7. -142 please write software version and reference or source

Re:  the R studio software has been cited and referenced 

8. -153 reference or name of producer with city and country

Re: the reference and citation were included. 

 

9. -183 Mite density is per leaf but it shows only mites found in domatia so it would be also interesting how number of domatia per leaf differs between tree species (or also season which probably also affects leaf size). If these data are available, it would be good to add them into Results.

Re: this is interesting, and we agree with the reviewer. Unfortunately, we did not record the average number of domatia per leaf for each species. We will consider this in future studies. 

 

10. -198 typo Neoseiulus

Re: the typo was corrected.

 

11. -198 and onwards: add authors names to all species

Re: the manes of the authors were added at the first mention of each species and in the table.

 

12. -199 typo Typhlodromus

Corrected.

13. -202 species which names are mentioned for the first time in the manuscript should be written in full (i.e. with full genera name) and author names.

Re: this has been corrected.

 

14. -215 Table - authors names at species should be consistent

Re: this has been corrected   

15. -218 Fig 5b typo Eriophyidae

Re: this has been corrected.

 

16. -279-280 Several papers documented that hairy leaves have much more mites complared to species with glabrous leaves (e.g. birch) - see papers by Tuovinen, Kabíček and others

Re: I was not able to access this paper.  

 

17. -287-288 linguistic corrections needed

Re: Section has been reworked.

18. 292 typo Neoseiulus

Re: this has been corrected

19. -296 typo Eriophyidae

Re: corrected

Reviewer 4 Report

Comments and Suggestions for Authors

Dear authors, I have reviewed your manuscript “The role of leaf domatia on seasonal variation in foliar mite diversity and abundance in three native South African forest plant species.”

On line 25: Suggestions the keywords should differ from those in the title, for example, leaf domatia.

Introduction section

Line 33. Suggestion: Rewrite the sentence by: Tilney et al. [10] mentioned that these structures facilitate an exchange of compounds between plants and mites.

To mention precisely that “a single study”, it would have to be justified that an extensive review was carried out in all databases such as the Web of Science, among others.

Line 61. What does “variety” refer to the different species of mites? Lifestyles of mite species? It is not common to call them “varieties of mites”.

“Variety and ecology of mites” is confusing

Change place [29] of line 75, at the end of the sentence, line 76 “autumn months [29]”.

Include the plant family.

 

Materials and Method section

2.1 Study site

Line 91. Check the presentation of the location coordinates of the study area.

Line 95 to 97. Improve wording since it is somewhat repetitive. Narrow it down.

Line 112 to 113. Confusing. Improve writing.

Line 131 to 133. Mention the code or registration number of the mite species with which they were registered in the NCA-PPRI.

Lines 122 to 133. They mention the total number of mites per species collected per plant species. Additionally, what was the percentage of mites per species or the number of mites per species that were mounted and sent to ARC, to determine the percentage of representativeness. Was the identification through male or female mites or both? What taxonomic keys were used to identify mite species? Institutions must provide the information for this information to be incorporated into the text of subsection 2.3.

Line 122. Why were mite individuals only taken from a single individual of each plant species? This is not significant for the sample size of plants.

What was the sampling method? There is none, because only one individual was shown. This reduces the likelihood of finding more mite species or confirming that only those mite species exist on the leaf domatia of each plant species.

On the other hand, the data is almost ten years old and too old; many events have occurred in that period of time (2015 to 2023); therefore, it is advisable to update said information and compare them between the two periods. So it would be corroborated that diversity has not changed or has already changed.

Subsection 2.4

Not having more individuals of each plant species will affect the average and variance of each mite species, resulting in “bias” (the results lose precision).

Results section

Line 158 to 159. They mention differences between autumn and the summer months. Does this mean that they compared the months or the seasons? Because the statistical test is different. The same for lines 159 to 168.

Author Response

Reviewer no 4

1. On line 25: Suggestions the keywords should differ from those in the title, for example, leaf domatia.

Re: the keywords were reconsidered.

 

Introduction section

2. Line 33. Suggestion: Rewrite the sentence by: Tilney et al. [10] mentioned that these structures facilitate an exchange of compounds between plants and mites.

To precisely mention that “a single study”, it would have to be justified that an extensive review was carried out in all databases such as the Web of Science, among others.

 

Re: we reworded the sentence to indicate this.

3. Line 61. What does “variety” refer to the different species of mites? Lifestyles of mite species? It is not common to call them “varieties of mites”.

“Variety and ecology of mites” is confusing

Re: we changed “variety” to “diversity”

4. Change place [29] of line 75, at the end of the sentence, line 76 “autumn months [29]”.

Re: this has been corrected.

 

5. Include the plant family.

Re: Name included

 

Materials and Method section

2.1 Study site

6. Line 91. Check the presentation of the location coordinates of the study area.

Re: we changed it to Degree Minute and Second

 

7. Line 95 to 97. Improve wording since it is somewhat repetitive. Narrow it down.

Re: this section has been reworked.

 

8. Line 112 to 113. Confusing. Improve writing.

Re: We have tried to clarify this text.

 

9. Line 131 to 133. Mention the code or registration number of the mite species with which they were registered in the NCA-PPRI.

Re: there were many slides produced some of which are not coded     

10. Lines 122 to 133. They mention the total number of mites per species collected per plant species. Additionally, what was the percentage of mites per species or the number of mites per species that were mounted and sent to ARC, to determine the percentage of representativeness. Was the identification through male or female mites or both? What taxonomic keys were used to identify mite species? Institutions must provide the information for this information to be incorporated into the text of subsection 2.3.

Re: we relied on the expertise of Professor Ueckermann, an established and internationally recognised Acarologist who contributed to the understanding of South African mite diversity. He was able to identify both males and females. In the paper specimens, we were not able to identify are stated.

11. Line 122. Why were mite individuals only taken from a single individual of each plant species? This is not significant for the sample size of plants.

Re:  We acknowledge this and this study can be considered as a preliminary investigation to excite other investigators to consider looking at mite seasonality.

 

12. What was the sampling method? There is none, because only one individual was shown. This reduces the likelihood of finding more mite species or confirming that only those mite species exist on the leaf domatia of each plant species.

Re: We collected 20 leaves and considered each a sample unit.

 

On the other hand, the data is almost ten years old and too old; many events have occurred in that period of time (2015 to 2023); therefore, it is advisable to update said information and compare them between the two periods. So it would be corroborated that diversity has not changed or has already changed.

Re: This is a nice idea, but we don’t live there anymore. This is a once-off snapshot.

 

Subsection 2.4

13. Not having more individuals of each plant species will affect the average and variance of each mite species, resulting in “bias” (the results lose precision).

Re: we agreed with the comment and in hindsight, acknowledge this weakness in our study design. We believed that we could consider the 20 leaves as independent samples because care was taken to collect the leaves all around the tree and far from each other.

 

Results section

14. Line 158 to 159. They mention differences between autumn and the summer months. Does this mean that they compared the months or the seasons? Because the statistical test is different. The same for lines 159 to 168.

Re: we compared seasons, the sentence was revised.

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

In general the authors made some improvements that let the text clearer, but some questions are still unsolved.

Authors need to review the zoological nomenclature, there are some typo errors along the manuscript. Species name that are not italicized and others italicized when must be not.

 

Author Response

Hi Reviewer, 

Please see the attached document with responses to your comments. 

 

Thank you.  

 

Author Response File: Author Response.pdf

Reviewer 4 Report

Comments and Suggestions for Authors

I have revised the manuscript again and you have substantially improved the manuscript.

Author Response

Dear Reviewer, 

Thank you for all your comments and suggestions. Please see further changes made to the manuscript in the attached file. 

Kind regards

 

Author Response File: Author Response.pdf