Search Results (761)

The widespread use of neonicotinoid insecticides has led to increasing resistance in non-target organisms, including the egg parasitoid Trichogramma dendrolimi, a crucial biological control agent. Film-residue bioassays on 17 geographic strains revealed striking inter-strain variability in susceptibility to imidacloprid, with mortality at a discriminating dose of 0.1 mg/L ranging from 25.7% to 87%. The most tolerant (FS) and least tolerant (HA) strains were subsequently selected for evaluation of biological parameters and comparative transcriptomics. Tolerant strains (FS) showed adaptive trade-offs: extended longevity (5.47 ± 0.57 d) and emergence (93.6 ± 1.9%), but reduced fecundity (54.6 ± 4.9 eggs) compared to HA. Transcriptome analysis revealed 2115 differentially expressed genes, with GO enrichment highlighting metabolic and detoxification pathways. KEGG analysis the most enriched pathways were “Protein digestion and absorption” and “Neuroactive ligand-receptor interaction”. RT-qPCR confirmed overexpression of CYP4C1, CYP6K1, and GstS1 in FS, indicating their potential roles in metabolic resistance if present. This study presents preliminary evidence of potential fitness trade-offs and molecular mechanisms that could underly imidacloprid resistance in T. dendrolimi, which may lead to important insights for resistance monitoring and more sustainable integrated pest management strategies. Full article

The woolly whitefly, Aleurothrixus floccosus, is likely a Neotropical origin species that has spread globally. Introduced to France in 1969, it became a pest in southern European citrus groves, first reported in Italy in 1974. Integrated management using biological control agents is crucial due to the low efficacy of chemical controls. Nymphs produce waxy filaments and honeydew, limiting insecticide contact. Natural enemies, especially from Neotropics, have been documented. The parasitoids Amitus spiniferus and Cales noacki were released in France in 1970 and later observed in Liguria, Italy. In the Campania region, C. noacki was first found on Aleurotuba jelineki in 1984 and this finding preceded the first report of A. floccosus in the same area. Subsequently, C. noacki was also introduced in other regions where it showed better adaptation throughout the Italian territory, reaching high parasitization levels on the woolly whitefly nymphs. After many years since the last field investigations, surveys in 2024–2025 in organic citrus groves in central and southern Italy identified additional parasitoids. Besides C. noacki and A. spiniferus, Eretmocerus paulistus and Signiphora xanthographa were found for the first time in Italy. Both species were originally described from the Neotropical ecozone. The aphelinid finding represents its first documented establishment in Italy, while the signiphorid one represents a new record for the European fauna. E. paulistus is a primary parasitoid, while S. xanthographa is a hyperparasitoid that can limit the effectiveness of other parasitoids. The interaction of these parasitoids resulted in high parasitism rates for A. floccosus nymphs. Preserving the current complexity of parasitoids in integrated pest management (IPM) programs could effectively control the woolly whitefly in central and southern Italy. Full article

Grapevineleafroll disease (GLD) is one of the more severe and persistent diseases in grapevines worldwide and is caused by several species of grape leafroll-associated viruses (GLRaVs). GLRaVs enter vines mainly by infected plant material or insect vectors. Mealybugs (Hemiptera: Pseudococcidae) are important vectors of GLRaVs and, among them, Pseudococcus viburni is the primary key vector in many regions. To reduce GLRaV spread, acquiring vines from virus-free certified nurseries, removing infected vines, and controlling insect vectors are crucial control tools. Sustainable mealybug control relies on eco-friendly products, cultural practices that limit mealybug population growth, and biological control by natural enemies. For P. viburni, biological control is primarily based on the action of predators and parasitoids, such as Cryptolaemus montrouzieri Mulsant and Acerophagus flavidulus Brethes, respectively, which will obviously have a different mode of action than chemical insecticides. However, the long-term effect of biological control on GLRaV spread within vineyards has rarely been studied. With the aim of better predicting the impact of biological control on insect vectors, such as mealybugs, we developed a mathematical model to predict the GLRaV spread. The results highlight the importance of establishing vineyards with virus-free material and having a pest management program that reduces the vector population to reduce the economic loss from GLRaVs. Full article

The black bug, Antiteuchus tripterus (Hemiptera: Pentatomidae), is one of the most important pests of cacao in Peru. Its control relies primarily on synthetic insecticides, which negatively impact the environment and the health of cacao farmers. Therefore, the use of natural enemies, such as entomopathogenic fungi, represents a promising and sustainable alternative. In this study, we aimed to characterize entomopathogenic fungal isolates obtained from naturally infected A. tripterus adults in Peru. Using morphological and molecular approaches, we identified the isolates as Purpureocillium takamizusanense. Then, we assessed their pathogenic potential against A. tripterus and identified their functional cell wall groups. To evaluate pathogenicity, A. tripterus nymphs were exposed to serially diluted conidial suspensions (10⁵–10⁹ conidia mL⁻¹; isolate 24M) in both laboratory and field trials. The isolates exhibited conidial viability above 99%. Concentration-mortality bioassays confirmed the lethal effect of P. takamizusanense against A. tripterus nymphs. The LC₅₀ was 1.65 × 10⁶ conidia mL^–1, while the LT₅₀ and LT₉₀ were 3.08 and 7.29 days, respectively. The field mortality rate was about 52%, which can be explained by the influence of the environment. Spectroscopy analyses revealed functional groups including chitin, glucans, lipids, aliphatic chains, and proteins, which may contribute to infection and fungal persistence. This study presents the first record of P. takamizusanense in the Americas and highlights its potential as a biocontrol agent against A. tripterus in cacao plantations. Full article

A key aspect of climate change’s impact on organisms lies in understanding their ability to adapt to shifting and stressful environmental conditions. Insects, such as parasitoid wasps, are particularly vulnerable due to limited heat tolerance. Adaptive strategies during mass rearing may enhance the efficacy and resilience of commercially reared biocontrol agents. This study assessed the effects of constant and fluctuating temperature regimens across four generations of mass-reared aphid parasitoids, examining their fitness traits and parasitism success under three thermal environments: colder [10 °C], standard [20 °C], and heat stress [28 °C]. Parasitoids reared under fluctuating temperatures [day/night: 25 °C/17 °C] showed increased parasitism, but reduced progeny survival compared to those reared at a constant temperature [20 °C]. Fluctuating regimens encouraged greater parasitism under heat stress, whereas constant regimens yielded intermediate parasitism across thermal environments, reflecting a pattern consistent with the evolution of specialist–generalist trade-offs. These findings underscore the value of developing adaptive temperature-rearing strategies for mass-rearing systems of parasitoids that more accurately simulate field conditions, improving their performance under climate stress. Future research involving diverse temperature regimens should deepen our understanding of trait trade-offs, such as survival and fecundity, and aid in identifying optimal thermal profiles to maximize efficacy in mass-rearing parasitoid wasps and their performance at the field level. Full article

The European spruce bark beetle, Ips typographus (Linnaeus, 1758), poses a significant threat to Picea abies (Linnaeus) Karsten, 1881 forests, with outbreaks often exacerbated by abiotic disturbances like the 2018 Vaia windstorm in the Italian Alps. Pheromone-baited traps are widely used for control, yet their overall efficacy and potential side effects, particularly the incidental capture of non-target insects, remain debated. This study aimed to comprehensively assess the presence and composition of non-target insects in I. typographus pheromone traps, used for both mass-trapping and monitoring, in the affected Alpine regions. We took into account single monitoring traps (dry collection) and three-trap cross configurations for mass-trapping (with preservative liquid), collecting and morphologically identifying insect by-catch. Our results revealed a non-target proportion (excluding bark beetles) significantly higher in mass-trapping (4.15%) compared to monitoring (1.00%), with approximately half being natural enemies of bark beetles. Crucially, we report that bark beetle parasitoids were repeatedly caught, with Tomicobia seitneri (Ruschka, 1924) (the third most abundant non-target species) particularly well represented, and Ropalophorus clavicornis (Wesmaël, 1835) also detected, which is noteworthy given its ecological role despite its lower numbers. Our findings underscore the significant, previously underreported, capture of beneficial parasitoids and highlight the need for careful consideration of non-target catches in I. typographus pest management strategies. Full article

Fruit fly (Diptera: Tephritidae) species are a serious threat for fruit-growers worldwide. The parasitoids (Hymenoptera) are natural enemies of these flies. In this context, the aim of this work was to assess fruit infestation by tephritid flies, both in native and exotic fruit trees, in the Southern region of Rio Grande do Sul (Brazil). Moreover, the incidence of native parasitoids on fly larvae was estimated. Fruits with signals of attack by fruit flies were collected randomly both in the trees and on the ground. From 2013 to 2015, a total of 5729 fruits (194.48 kg) were collected, corresponding to 34 tree species from 16 botanical families. Fruits were taken to the laboratory, individualized, weighted and kept in vermiculite for pupae emergence. Pupae were counted and emerged adults were counted and identified. The association between fruit flies, hosts and parasitoids was determined when only a given species of tephritid emerged. Half of the sampled fruit tree species presented infestation by flies. The main species of tephritid fly was Anastrepha fraterculus. This study showed that natural parasitism rates of fruit flies were low; however, several parasitoid species from the Figitidae and Braconidae families were detected, including Aganaspis pelleranoi, Doryctobracon areolatus, Doryctobracon brasiliensis, Opius bellus, Utetes anastrephae, and Cerchysiella insularis. Full article

Tea is a global commodity, and due to its way of preparation pesticide residues cannot be tolerated. This underlines the importance of non-chemical pest control. Kenya is the third largest global tea producer but the potential of natural enemies against tea pests is unknown. We used artificial caterpillars made of non-drying green plasticine to quantify attack rates by predators on tea canopies at different distances from plantation edges and in the nearby native forest during the wet and dry seasons in three tea-growing mountain regions of Kenya, Kericho, Gatamaiyu and Kakamega. The artificial sentinel caterpillars were readily attacked by arthropods, birds, and sporadically by small mammals. During an exposure time of 24 h, the overall attack rate was 25.0%d⁻¹. Natural enemy activity was higher in the dry (35.3%d⁻¹) than in the wet (16.7%d⁻¹) season. The highest predation pressure was measured in the native forest (41.7%d⁻¹) and gradually decreased with increasing distances into the tea plantation (to 8.3%d⁻¹ at 40 m from the edge). The rate of decrease from the forest edge towards the centre of the tea plantation was steeper for birds than for arthropods, indicating that birds were more reluctant to use this habitat. The potential for natural pest control in Kenyan tea plantations is high, but planting native trees is recommended especially if bird activity inside tea plantations is to be encouraged. Full article

Paracoccus marginatus (Hemiptera: Pseudococcidae) poses a significant threat to over 200 plant species, severely impacting agricultural productivity. Diomus guilavoguii (Coleoptera: Coccinellidae) is a natural predator of P. marginatus. To develop an effective and environmentally friendly management strategy against P. marginatus, this study investigates the predation relationship between D. guilavoguii and P. marginatus by focusing on functional response and mutual interference under controlled laboratory conditions (Petri dishes). The results indicated that D. guilavoguii exhibits a type II functional response toward P. marginatus, with adults of D. guilavoguii demonstrating superior efficiency in preying upon P. marginatus (the theoretical daily maximum predation rate for female adults of D. guilavoguii on young mealybugs is 416.667). However, a decrease in the predators’ search effect was observed with increasing prey density. Additionally, interspecific interference competition intensified as the number of predators increased, resulting in reduced predation efficiency. Consequently, D. guilavoguii shows promise biological control agent for the management of P. marginatus under laboratory conditions, although further studies in greenhouse and field environments are required to validate its potential in practical pest management. Full article

Biological and integrated pest management strategies have recently been widely adopted in crop protection, with one of the key approaches involving the use of natural enemies (predators and parasites). In order to identify and monitor beneficial arthropod species associated with winter wheat crops, an experiment was conducted between 2022 and 2024 in two locations in the Transylvanian Plateau: Turda, within an open-field agroecosystem, and Bolduţ, within an agroecosystem with protective agroforestry shelterbelts. The research aimed to evaluate the diversity of beneficial arthropod fauna in two agroecosystems, as well as the impact of insecticide treatments on the natural enemies of wheat pests. According to our findings, it can be stated that the beneficial arthropods identified in the two agroecosystems belonging to the same groups, but the abundance in all three years is higher in the agroecosystem with agroforestry shelterbelts. Among all the analyzed arthropods, the order Araneae was characterized by the highest abundance, recording 995 individuals in an insecticide-free variant in 2022. The treated variants with insecticide showed a decrease in both abundance and diversity in agroecosystems with and without shelterbelts during all three experimental years, compared to the variant without insecticides. Regarding abundance, the largest difference was recorded in 2024 in the shelterbelt agroecosystem with a reduction of 781 individuals. In terms of diversity, the lowest value was observed for the Shannon_H index in open-field agroecosystem in 2024 for the variant treated with insecticides (1.426), compared to the untreated variant, where the index reached a value of 1.841. The application of insecticide treatments caused an increase in the mortality of beneficial arthropods, reaching its highest level in 2024. Full article

Cauliflower, a widely cultivated vegetable crop valued for its edible curds, faces a persistent threat from insect pests, which are typically managed using synthetic insecticides. This study evaluated the benefits of intercropping practices as part of an ecological pest management strategy in cauliflower cultivation during the winter seasons of 2017–18 and 2021–22. Nine insect pests belonging to six families of three orders were recorded. The calendula intercropping system (IS) consistently showed the lowest infestation by Plutella xylostella and Pieris brassicae/plant. Calendula IS had attracted the highest numbers of syrphids, Cotesia glomerata, Diaeretiella rapae, Cotesia vestalis, and coccinellids such as Coccinella septempunctata and Cheilomenes sexmaculata. In candytuft IS, a strong tri-trophic interaction between the flower and D. rapae significantly reduced aphid populations, for each additional D. rapae, aphid numbers decreased by 48.53 in 2018. The marigold IS recorded the highest Shannon diversity index in 2021–22. The longest adult survival of C. septempunctata (8.67 ± 3.35 days), in the absence of aphids was recorded on candytuft flowers. The total sugars and protein in flowers positively influenced the longevity of the adult coccinellid beetles (R²-40.42 and 20.79%, respectively). Calendula intercropping yielded the highest revenue return of Indian rupee (₹) 11.33 per INR 1 invested, compared to the cauliflower monocrop (1.58). These findings demonstrate that, intercropping and habitat manipulation can enhance ecological pest control and reduce the dependence on synthetic chemicals. Full article

Anastrepha fraterculus (Wiedemann) (Diptera: Tephritidae) is a significant fruit pest of economic and quarantine importance in South America. Biological control using augmentative releases of parasitoids or conservation strategies for these natural enemies are handy tools in integrated fruit fly management programs. The functional response describes the natural enemy consumption rate with increasing resource density. Such information may be relevant for selecting the parasitoid species that is potentially most suitable to serve as a biocontrol agent of A. fraterculus. Furthermore, the number of discarded hosts determined from functional response analysis might be used to estimate suitable host densities, avoiding wastage of larvae/puparia associated with host overproduction. Therefore, the current study aimed to evaluate the functional response of four Neotropical-native parasitoid species commonly associated with species of the Anastrepha genus in the Americas, such as the pupal parasitoid Coptera haywardi (Ogloblin) (Hymenoptera: Diapriidae) and the larval parasitoids Ganaspis pelleranoi (Brèthes) (Hymenoptera: Figitidae), Doryctobracon crawfordi (Viereck), and Opius bellus Gahan (Hymenoptera: Braconidae). The package “frair” from R software was used to determine the functional response type and parameter estimation, enabling selection, fitting, and comparison among standard functional response models and integral parameters. Four relevant conclusions can be highlighted: (a) G. pelleranoi showed a flexible functional response, with a statistically significant deviation to a Type III rather than a Type II response found among the three other parasitoid species; (b) G. pelleranoi had a handling time significantly lower than the other tested parasitoid species; (c) the number of attacked hosts varied among all four parasitoid species, with C. haywardi and G. pelleranoi exhibiting the highest proportion of attacks at low and high host densities, respectively; and (d) the percentage of discarded hosts was significantly low at 1–5 and 1–20 hosts per parasitoid in C. haywardi and G. pelleranoi, respectively, whereas in both D. crawfordi and O. bellus, it was high at any offered host density. Results provide helpful comparative information about the possible performance of these species as biocontrol agents against A. fraterculus populations within augmentative and/or conservative biological control programs. Full article

Although traditional genetically modified (GM) cotton has reduced lepidopteran pests, secondary pests such as Adelphocoris suturalis Jakovlev (Hemiptera: Miridae) have become increasingly problematic. RNA interference (RNAi)-based insect-resistant plants offer a promising alternative, but their potential ecological risks, particularly within the plant–pest–natural enemy framework, require comprehensive evaluation. As a key natural enemy in cotton agroecosystems, Harmonia axyridis Pallas (Coleoptera: Coccinellidae) plays a vital role in regulating pest populations and thus serves as an important non-target insect for environmental risk assessment. In this study, dsAsFAR transgenic cotton and the non-target insect H. axyridis were used to evaluate potential ecological risks. Based on the sequences of the HaFAR, AsFAR, and GFP genes, dsAsFAR, dsHaFAR, and dsGFP were synthesized in vitro and incorporated into artificial diets fed to H. axyridis, along with a ddH₂O control group. No significant differences were observed among the treatments across various developmental stages. Furthermore, H. axyridis was fed aphids that had been reared on either transgenic or non-transgenic cotton plants cultivated in a greenhouse. The findings indicated no significant differences in the growth, development, predatory ability, or fecundity of H. axyridis. These results suggest that transgenic dsAsFAR cotton targeting A. suturalis poses no detectable adverse effects on H. axyridis, supporting the environmental safety of RNAi crops within a plant–pest–natural enemy ecological interaction framework. Moreover, the dsAsFAR expressed in transgenic cotton was not effectively transferred through the food chain to affect homologous gene expression in H. axyridis. Full article

Lygus pratensis is a major pest of cotton, causing serious damage to cotton production. This study designed species-specific PCR detection primers for L. pratensis, established a detection system to identify L. pratensis DNA in the intestinal contents of predatory natural enemies, and investigated the control potential of four species’ predatory natural enemies against L. pratensis. The results indicated that 826 predatory natural enemies were collected from cotton fields belonging to two classes, five orders, and twelve families. Among these, 9 species of insecta natural enemies accounted for 54.12% of the total number of predatory natural enemies collected, while 14 species of arachnida predatory natural enemies comprised 45.88%. Of the 806 natural enemies tested, 5.58% were found to be positive for L. pratensis, all of which were arachnid predators, specifically Ebrechtella tricuspidata, Xysticus ephippiatus, Hylyphantes graminicola, and Oxyopes sertatus. The predation response of these four spider species to the fourth to fifth instar nymphs and adults of L. pratensis adhered to the Holling II model. The theoretical predation (a′/Th), daily maximum predation rate (T/Th), and searching effect for the fourth to fifth instar nymphs and adults of L. pratensis of the four spider species were assessed. According to the results, the species can be ranked in terms of their predatory and searching efficiency as follows: O. sertatus > E. tricuspidata > X. ephippiatus > H. graminicola. Four species of spiders had the highest theoretical predation against L. pratensis nymphs, ranging from 23.71 to 60.86, and adults, ranging from 22.14 to 50.25. Therefore, these four spider species could be utilized for L. pratensis management. This study identified the main predatory natural enemies of L. pratensis and their pest control capabilities, providing a scientific basis for selecting and utilizing natural enemies in integrated pest management (IPM) strategies. This will help promote ecological and green pest control of L. pratensis in cotton-growing areas. Full article

Bee pollination is an indispensable part of agricultural production and a crucial factor in maintaining ecosystem balance and biodiversity. Understanding foraging behavior and pollination effects is essential for the management of bee pollination. Over a two-year experiment, we evaluated the foraging behavior and pollination effects of bumblebee Bombus terrestris and Chinese honeybee Apis cerana cerana on cherries in orchards. Results showed that all bees exhibited enhanced foraging activity as daytime temperatures rose in early spring. However, the daytime foraging activity of bumblebees differs from that of Chinese honeybees. The number of bumblebees leaving the hive exhibited two peak periods, whereas Chinese honeybees showed only one peak period. Bumblebees had longer working hours and greater pollen-carrying capacity than Chinese honeybees. Undoubtedly, cherries pollinated by bees had higher yields, as indicated by a greater fruit setting rate and yield. Thus, as effective pollinators, their pollination significantly boosts production and presents a viable option for widespread use in cherry cultivation. However, the risk of biological invasion by exotic bumblebees cannot be overlooked before extensive use. Full article