Insect Pathogens as Biocontrol Agents Against Pests

A special issue of Insects (ISSN 2075-4450). This special issue belongs to the section "Insect Behavior and Pathology".

Deadline for manuscript submissions: closed (28 February 2026) | Viewed by 11735

Special Issue Editors

Department of Biosciences, Swansea University, Singleton Park, Swansea SA2 PP, UK
Interests: entomopathogenic fungi; endophytes; fungal metabolites; biocontrol; biostimulants; host–pathogen interactions; mass production; formulation; ecological fitness risk assessment
Special Issues, Collections and Topics in MDPI journals

Special Issue Information

Dear Colleagues,

Entomopathogens are microorganisms that are pathogenic to arthropods such as insects, mites, and ticks. Several species differ significantly in their biology and behavior and, hence, in their ability to control enemy populations in all environments. The proper use of entomopathogens requires good knowledge of the biological cycle of enemies. Entomopathogens such as bacteria, fungi, nematodes, and viruses infect a variety of arthropod pests and play an important role in their management. The pathogenicity caused by entomopathogens is not the same in all insects and differs even at each insect stage, usually being larger in young specimens, especially during the larval stage. The point of entry or growth of a pathogen also varies depending on the insect and entomopathogen: entomopathogens (usually viruses and bacteria) enter via the oral route, while fungi can invade their host from the insect cuticle. Some entomopathogens are mass-produced in vitro (bacteria, fungi) or in vivo (viruses) and sold commercially. In this Special Issue, we welcome original research and review articles covering this area of study.

Dr. Spiridon Mantzoukas
Dr. Tariq Butt
Prof. Dr. Panagiotis A. Eliopoulos
Guest Editors

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 250 words) can be sent to the Editorial Office for assessment.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Insects is an international peer-reviewed open access monthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2600 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

  • entomopathogens
  • IPM
  • tri-trophic interactions
  • biological control crop and forestry pests
  • host–pathogen interactions

Benefits of Publishing in a Special Issue

  • Ease of navigation: Grouping papers by topic helps scholars navigate broad scope journals more efficiently.
  • Greater discoverability: Special Issues support the reach and impact of scientific research. Articles in Special Issues are more discoverable and cited more frequently.
  • Expansion of research network: Special Issues facilitate connections among authors, fostering scientific collaborations.
  • External promotion: Articles in Special Issues are often promoted through the journal's social media, increasing their visibility.
  • Reprint: MDPI Books provides the opportunity to republish successful Special Issues in book format, both online and in print.

Further information on MDPI's Special Issue policies can be found here.

Related Special Issue

Published Papers (13 papers)

Order results
Result details
Select all
Export citation of selected articles as:

Research

Jump to: Review

17 pages, 5783 KB  
Article
Effect of the Entomopathogenic Fungus Beauveria bassiana (Balsamo) Vuillemin (Strain PPRI5339) on Nymphs of the Calliptamus italicus (Orthoptera: Acrididae) Under Laboratory Conditions
by Spyridon Mantzoukas, Constantina Stamou, Aimilia Lachlou, Vasilis Kotsantis, Ioannis Lagogiannis, Stergios Bitivanos, Dimitris Servis and Panagiotis A. Eliopoulos
Insects 2026, 17(6), 545; https://doi.org/10.3390/insects17060545 - 23 May 2026
Viewed by 377
Abstract
The entomopathogenic fungus Beauveria bassiana (Hypocreales: Cordycipitaceae) is widely used as a biological control agent, yet its efficacy against orthopteran pests remains poorly characterized. In this study, we evaluated the susceptibility of second-, third-, and fourth-instar nymphs of the Italian locust, Calliptamus italics [...] Read more.
The entomopathogenic fungus Beauveria bassiana (Hypocreales: Cordycipitaceae) is widely used as a biological control agent, yet its efficacy against orthopteran pests remains poorly characterized. In this study, we evaluated the susceptibility of second-, third-, and fourth-instar nymphs of the Italian locust, Calliptamus italics (Orthoptera: Acrididae), to B. bassiana strain PPRI5339 under controlled laboratory conditions. Nymphs were exposed to six conidial concentrations (1 × 103 to 1 × 108 conidia/mL) via treated food, with mortality recorded over 10 days. The fungus caused significant, dose- and time-dependent mortality across all instars. Second-instar nymphs exhibited the highest susceptibility, with an LC50 of 5.8 × 105 conidia/mL and an LT50 of 3.1 days at the highest concentration. Susceptibility decreased with advancing developmental stage; fourth-instar nymphs required higher concentrations and longer exposure to achieve comparable mortality (LC50 = 2.3 × 106 conidia/mL; LT50 = 4.5 days). Cox proportional hazards analysis confirmed that the mortality hazard was significantly lower for third (HR = 0.66) and fourth (HR = 0.51) instars compared to second instars (HR = 1.00). These results demonstrate that B. bassiana is pathogenic to C. italicus, with pronounced stage-dependent susceptibility. Full article
(This article belongs to the Special Issue Insect Pathogens as Biocontrol Agents Against Pests)
Show Figures

Figure 1

16 pages, 6455 KB  
Article
Isolation, Identification and Measurement of Virulence Against the Potato Tuber Moth, Phthorimaea operculella, of Metarhizium robertsii ML-2
by Lingying Zhang, Zaotang Su, Yaning Wang, Zhao Qiu, Yijie Zuo, Yuhe Dai, Bin Chen and Guanli Xiao
Insects 2026, 17(5), 474; https://doi.org/10.3390/insects17050474 - 4 May 2026
Viewed by 482
Abstract
Phthorimaea operculella is a globally distributed pest of solanaceous crops and represents one of the most critical constraints on potato production worldwide. The overuse of chemical insecticides has led to widespread resistance in pest populations, making entomopathogenic fungi a promising alternative strategy for [...] Read more.
Phthorimaea operculella is a globally distributed pest of solanaceous crops and represents one of the most critical constraints on potato production worldwide. The overuse of chemical insecticides has led to widespread resistance in pest populations, making entomopathogenic fungi a promising alternative strategy for sustainable agricultural pest management. In this study, a fungal strain designated ML-2 was isolated from naturally infected P. operculella larvae collected from a potato field in Yunnan province, China. Through morphological characteristics and ITS sequence analysis, strain ML-2 was identified as M. robertsii. The growth rate and sporulation yield on PDA and SDAY media were assessed, the virulence of ML-2 against eggs, larvae, and pupae of P. operculella were determined using the dipping method, and the data were analyzed via the time-concentration-mortality (TCM) model. The results showed that there were no significant differences in the growth rate of strain ML-2 on the two culture media (p > 0.05), whereas the sporulation yield on PDA medium was significantly higher than that on SDAY medium (p < 0.01). The highest corrected cumulative mortality rates for P. operculella larvae and pupae were 94.50% and 83.07% on day 7 after inoculation, respectively, while the highest cumulative mortality rate for eggs was relatively low at only 20.28%. Additionally, at a concentration of 1 × 108 spores/mL, the LT50 values of strain ML-2 against P. operculella larvae and pupae were 2.34 days and 2.72 days, respectively. On day 7 post-inoculation, the LC50 values for larvae and pupae were 3.24 × 107 conidia/mL and 9.64 × 105 conidia/mL, respectively. In conclusion, M. robertsii ML-2 exhibits high potential as a candidate biopesticide and can be used in the sustainable integrated management of P. operculella. Full article
(This article belongs to the Special Issue Insect Pathogens as Biocontrol Agents Against Pests)
Show Figures

Figure 1

15 pages, 10084 KB  
Article
Comparison of T7 In Vitro Transcription and E. coli Expression Systems for RNAi-Based Control of Euproctis pseudoconspersa by Targeting EpCHSA
by Linyuan Huang, Fanhui Meng, Jinxiu Yu, Ying Luo, Zhen Liu, Wan Deng, Mi Li, Xiudan Wang and Yifei Xie
Insects 2026, 17(5), 453; https://doi.org/10.3390/insects17050453 - 24 Apr 2026
Viewed by 310
Abstract
Euproctis pseudoconspersa is a devastating pest in Camellia oleifera plantations, necessitating the development of sustainable molecular intervention strategies. This study targeted the chitin synthase A gene (EpCHSA) to evaluate and compare the RNA interference (RNAi) efficacy of dsRNA synthesized via the [...] Read more.
Euproctis pseudoconspersa is a devastating pest in Camellia oleifera plantations, necessitating the development of sustainable molecular intervention strategies. This study targeted the chitin synthase A gene (EpCHSA) to evaluate and compare the RNA interference (RNAi) efficacy of dsRNA synthesized via the T7 in vitro transcription system and the Escherichia coli HT115 (DE3) expression system. The EpCHSA gene (2199 bp ORF) was cloned and characterized, exhibiting peak expression during the fourth-instar stage, and predominantly in the head tissues of fifth-instar larvae. Bioassays demonstrated that larvae fed with 500 ng/μL in vitro synthesized dsRNA exhibited continuous gene silencing for five days, reaching a maximum efficiency of 68.1%. Conversely, treatment with 100× concentrated bacterial broth (5000 ng/μL) elicited a superior silencing effect of 79.3% within 24 h. Furthermore, the bacterial treatment group reached a 14-day mortality rate of 46.66%, significantly higher than the in vitro group (38.33%). Both methods induced severe phenotypic abnormalities, including molting failure and pupal malformation. These findings conclude that the E. coli expression system offers a cost-effective and highly potent platform for dsRNA production. This research provides a critical technical foundation and promising application prospects for the field-scale management of E. pseudoconspersa utilizing RNAi-based biopesticides. Full article
(This article belongs to the Special Issue Insect Pathogens as Biocontrol Agents Against Pests)
Show Figures

Figure 1

16 pages, 2917 KB  
Article
Effects of the Stress of Beauveria bassiana on the Reproductive Success of an Idiobiont Parasitoid, Sclerodermus guani
by Yuenan Chen, Shasha Wu, Li Li, Hongmei Yao and Lilin Luo
Insects 2026, 17(3), 278; https://doi.org/10.3390/insects17030278 - 4 Mar 2026
Viewed by 702
Abstract
In the complex interplay among parasitic wasps, their insect hosts, and pathogenic microbes, the system involving Sclerodermus guani (Hymenoptera: Bethylidae) (a parasitoid wasp), Monochamus alternatus (Coleoptera: Cerambycidae) (the pine sawyer beetle, its host), and Beauveria bassiana (Hypocreales: Cordycipitaceae) (a fungus) presents a unique [...] Read more.
In the complex interplay among parasitic wasps, their insect hosts, and pathogenic microbes, the system involving Sclerodermus guani (Hymenoptera: Bethylidae) (a parasitoid wasp), Monochamus alternatus (Coleoptera: Cerambycidae) (the pine sawyer beetle, its host), and Beauveria bassiana (Hypocreales: Cordycipitaceae) (a fungus) presents a unique scenario where wasp offspring develop within a nearly sealed host gallery. This nursery is vulnerable to fungal invasion, often introduced by the foraging female wasps or M. alternatus itself, creating a three-way interaction where the fungus can infect both M. alternatus and S. guani. To assess how the route and timing of fungal exposure impact the S. guani population, we simulated this system by introducing different concentrations of B. bassiana either directly to the female wasps or to M. alternatus prior to parasitism. We further examined the effect of exposure timing by applying the fungus at different developmental stages of the S. guani offspring. Key population parameters, including the reproductive capacity of female wasps, the survival and developmental fitness of S. guani offspring and the germination period of hyphae, were measured. The results indicated that the most severe damage to populations of S. guani occurs when its host, M. alternatus, is infected by B. bassiana. Among the various developmental stages, S. guani offspring exhibited the greatest vulnerability during mid-to-late larval stages, whereas the egg and pupa within cocoon stages demonstrated a higher tolerance. We conclude that both the pathway and the timing of fungal exposure are critical factors influencing its impact. These findings provide valuable insights for optimizing the integrated use of biological agents in pest management, informing strategies that mitigate adverse effects on beneficial parasitoid wasps. Full article
(This article belongs to the Special Issue Insect Pathogens as Biocontrol Agents Against Pests)
Show Figures

Figure 1

22 pages, 9545 KB  
Article
Immune and Metabolic Responses in Ectropis grisescens Infected by Metarhizium anisopliae: Insights from Transcriptome and Metabolome Analyses
by Xiaozhu Wu, Xiaomin Xiong, Muxiang Dai, Juanjuan Cai, Suqing Zhu, Lisi He, Gongmin Cheng, Maosheng Gu, Hao Meng, Feng Wen and Liande Wang
Insects 2026, 17(3), 262; https://doi.org/10.3390/insects17030262 - 28 Feb 2026
Viewed by 672
Abstract
The tea geometrid (Ectropis grisescens) is a significant pest in Chinese tea plantations. Although Metarhizium anisopliae serves as an environmentally friendly biocontrol agent against E. grisescens, the molecular mechanisms underlying the insect’s immune response remain unclear. This study investigates changes [...] Read more.
The tea geometrid (Ectropis grisescens) is a significant pest in Chinese tea plantations. Although Metarhizium anisopliae serves as an environmentally friendly biocontrol agent against E. grisescens, the molecular mechanisms underlying the insect’s immune response remain unclear. This study investigates changes in immunity-related genes and metabolites in E. grisescens larvae infected with a virulent strain of M. anisopliae through transcriptome sequencing and metabolome analysis. We identified 2409 differentially expressed genes (DEGs) at 48 h post-infection, with 1611 genes up-regulated. GO analysis revealed that 119 DEGs were significantly enriched in immune-related processes. Additionally, 1860 differentially accumulated metabolites (DAMs) were detected, including 652 up-regulated and 1208 down-regulated metabolites, with 236 significantly enriched in 82 KEGG pathways. These findings indicate the activation of immunity-related and detoxifying enzyme-related genes, providing new insights into the physiological and biochemical responses of insects to biopesticides and potential targets for controlling tea geometrid. Full article
(This article belongs to the Special Issue Insect Pathogens as Biocontrol Agents Against Pests)
Show Figures

Figure 1

19 pages, 1971 KB  
Article
Intraguild Predation and Chemical Cue Responses Between Phytoseiulus persimilis and Neoseiulus californicus in Laboratory Assays
by Fatma Sh. Kalmosh, Bo Zhang, Nikola Đukić, Abdulaziz Alamri, Salman Alrokayan and Xuenong Xu
Insects 2026, 17(2), 157; https://doi.org/10.3390/insects17020157 - 31 Jan 2026
Cited by 1 | Viewed by 874
Abstract
Species sharing the same trophic level can interact not only through competition for resources but also through intraguild predation (IGP). Therefore, an important step toward implementing successful multiple predator releases in biological control strategies requires resolving how predators respond to the presence of [...] Read more.
Species sharing the same trophic level can interact not only through competition for resources but also through intraguild predation (IGP). Therefore, an important step toward implementing successful multiple predator releases in biological control strategies requires resolving how predators respond to the presence of heterogeneous competitors. This study examined the compatibility of two predatory mites, N. californicus and P. persimilis, which are both widely employed to suppress two-spotted spider mite populations in greenhouses and open fields. The experiments quantified the frequency and intensity of IGP across different developmental stages of these species on bean leaves, considering scenarios both with and without their shared prey being present. Additionally, a Y-tube olfactometer was employed to assess whether either predator avoided prey patches previously occupied by other heterospecifics, thereby providing insights into potential chemical cues that influence predator behavior. The results revealed that adult females of both predatory mite species predominantly targeted heterospecific eggs and larvae, whereas adults were largely avoided. In the absence of shared prey, N. californicus attacked 83% of the P. persimilis larvae and 37% of the eggs, whereas P. persimilis consumed 67% of the N. californicus eggs. The presence of shared prey reduced IGP risk by approximately 60%. Olfactometer assays revealed no significant avoidance of plants inhabited by heterospecifics at densities of 20 or 40 adults; both predators were similarly attracted to herbivore-induced volatiles. Generalized linear models indicated that host plant experience had a significant influence on the foraging response of N. californicus, whereas the effects of the feeding state weakened over time. Understanding predator foraging plasticity and responsiveness to chemical cues can help optimize biological control strategies in complex agroecosystems. Full article
(This article belongs to the Special Issue Insect Pathogens as Biocontrol Agents Against Pests)
Show Figures

Figure 1

19 pages, 3309 KB  
Article
Response of Energy Reserves in Entomopathogenic Nematodes to Drought-Stress and Expression Analysis of Energy Metabolism-Related Genes in Arid Areas
by Xia Wu, Wenliang Li, Tingwei Zhang, Hong Chen, Wende Zhang, Xingduo Wang and Xiujuan Qian
Insects 2026, 17(1), 22; https://doi.org/10.3390/insects17010022 - 23 Dec 2025
Viewed by 626
Abstract
The free-living infective juveniles of entomopathogenic nematodes (EPNs) are critical biological control agents against insect pests. The field efficacy of EPNs is largely determined by their tolerance to low-humidity stress, a trait closely linked to the mobilization of their energy reserves. This study [...] Read more.
The free-living infective juveniles of entomopathogenic nematodes (EPNs) are critical biological control agents against insect pests. The field efficacy of EPNs is largely determined by their tolerance to low-humidity stress, a trait closely linked to the mobilization of their energy reserves. This study aims to investigate how varying levels of humidity stress influence energy reserve dynamics in two EPNs, Steinernema kraussei 0657L and Heterorhabditis brevicaudis 0641TY, and their relationship with the survival rate and pathogenicity. The results demonstrated that lipids were the predominant energy reserve, followed by proteins and sugars. Notably, neutral lipid constituted approximately 3% of the total lipid content. Among sugars, soluble sugar levels were the highest, followed by glycogen and trehalose. Exposure to low-humidity stress resulted in increased levels of protein, total lipid, glycogen, and trehalose in nematodes. These increases were more pronounced in S. kraussei 0657L, a highly drought-resistant strain, compared to H. brevicaudis 0641TY. Furthermore, the accumulation of protein, total lipid, and trehalose was negatively correlated with survival rate and pathogenicity. However, positive correlations were observed between trehalose and both total lipids and soluble sugars. Furthermore, transcriptome analysis revealed that under low-humidity stress, S. kraussei 0657L exhibited an enrichment of differentially expressed genes (DEGs) involved in glycolysis/gluconeogenesis, fatty acid metabolism, and glycerophospholipid metabolism pathways. This indicates that S. kraussei 0657L regulated energy metabolism to adapt to low-humidity stress. These findings provide insights into the mechanisms underlying drought resistance in EPNs and offer an experimental basis for their application in arid environments. Full article
(This article belongs to the Special Issue Insect Pathogens as Biocontrol Agents Against Pests)
Show Figures

Figure 1

24 pages, 1629 KB  
Article
Analysis of the Bacterial Microbiota in Wild Populations of Prickly Pear Cochineal, Dactylopius opuntiae in Morocco
by Imane Remmal, Youssef El Yamlahi, Naima Bel Mokhtar, Ioannis Galiatsatos, Dimitrios Loukovitis, Eva Dionyssopoulou, Mohammed Reda Britel, Panagiota Stathopoulou, Amal Maurady and George Tsiamis
Insects 2025, 16(12), 1184; https://doi.org/10.3390/insects16121184 - 21 Nov 2025
Viewed by 1448
Abstract
Dactylopius opuntiae (Cockerell) (Hemiptera: Dactylopiidae), the wild cochineal scale, is a major pest of prickly pear crops worldwide. This study characterized the bacterial community structure of D. opuntiae from four Moroccan regions using targeted PCR and full-length 16S rRNA MinION sequencing. We report [...] Read more.
Dactylopius opuntiae (Cockerell) (Hemiptera: Dactylopiidae), the wild cochineal scale, is a major pest of prickly pear crops worldwide. This study characterized the bacterial community structure of D. opuntiae from four Moroccan regions using targeted PCR and full-length 16S rRNA MinION sequencing. We report the first detection of Wolbachia (16.6% prevalence) in D. opuntiae, with infection rates varying geographically from 0% (Rabat) to 53.3% (Ouazzane). Spiroplasma was detected at a lower prevalence (3.3%) and exclusively in males. Phylogenetic analysis showed that Wolbachia sequences likely belong to supergroup B, based on their similarity to reference sequences, while Spiroplasma sequences were placed within the poulsonii–citri complex. MinION sequencing revealed Candidatus Dactylopiibacterium as the dominant taxon (97.7%), consistent with its role as an obligate symbiont. After removing this dominant species, we uncovered a diverse bacterial community, including Flavisolibacter, Pseudomonas, Phyllobacterium, Acinetobacter, and Brevibacillus. Beta diversity analysis showed significant geographic variation (PERMANOVA p < 0.008), with distinct communities across regions. Females harbored a more specialized microbiome dominated by Flavisolibacter (except in Agadir), whereas males and nymphs showed Pseudomonas dominance. Core microbiome analysis revealed no universal genera across all groups, with females displaying a more restricted core than males and nymphs. The detection of reproductive symbionts, combined with geographic and sex-specific microbiome patterns, provides valuable insights into the potential roles of these bacteria in host adaptation and their implications for microbiome-based pest management strategies. The complementary use of targeted and untargeted sequencing methods is essential for comprehensive microbiome characterization in this economically important pest. Full article
(This article belongs to the Special Issue Insect Pathogens as Biocontrol Agents Against Pests)
Show Figures

Graphical abstract

12 pages, 2195 KB  
Article
Diversity and Influencing Factors of Endosymbiotic Bacteria in Tetranychus truncatus Sourced from Major Crops in Xinjiang
by Kaiqin Mu, Bing Zhang, Zhiping Cai, Jing Chen, Jianping Zhang and Jie Su
Insects 2025, 16(11), 1126; https://doi.org/10.3390/insects16111126 - 4 Nov 2025
Viewed by 832
Abstract
The Xinjiang Uygur Autonomous Region, situated in northwest China, boasts a unique geographical position and a consequent variety of environmental characteristics. T. truncatus is prevalent throughout this region as the primary pest affecting various crops. In this study, we analyzed the microbial community [...] Read more.
The Xinjiang Uygur Autonomous Region, situated in northwest China, boasts a unique geographical position and a consequent variety of environmental characteristics. T. truncatus is prevalent throughout this region as the primary pest affecting various crops. In this study, we analyzed the microbial community structures of endosymbiotic bacteria in T. truncatus collected from 17 regions and three host plants in Xinjiang using 16S rRNA sequencing. Through composition analysis of the endosymbiotic bacteria in T. truncatus from Xinjiang, it was found that the dominant bacterial phyla were Pseudomonadota and Bacillota. At the genus level, in addition to Wolbachia, Cardinium, and Spiroplasma (common symbiotic bacteria in T. truncatus), the infection rate of Rickettsia in T. truncatus in Xinjiang was found to be 92.8%. The diversity of the endosymbiotic bacteria community in T. truncatus is shaped by both host plant species and geographical region. Specifically, the endosymbiotic bacterial diversity in T. truncatus populations on corn was significantly higher than that observed in populations on cotton and soybean (p < 0.05). Furthermore, we discovered the diversity of endosymbiotic bacteria in T. truncatus was significantly higher in southern Xinjiang than in northern Xinjiang (p < 0.05). Full article
(This article belongs to the Special Issue Insect Pathogens as Biocontrol Agents Against Pests)
Show Figures

Figure 1

16 pages, 2278 KB  
Article
Isolation and Characterization of a Native Metarhizium rileyi Strain Mrpgbm2408 from Paralipsa gularis in Maize: First Data on Efficacy and Enzymatic Host Response Dynamics
by Yunhao Yao, Kaiyu Fu, Xiaoyu Wang, Guangzu Du, Yuejin Peng, Guy Smagghe, Wenqian Wang and Bin Chen
Insects 2025, 16(9), 872; https://doi.org/10.3390/insects16090872 - 22 Aug 2025
Viewed by 1377
Abstract
Paralipsa gularis (Zeller) has become an increasingly destructive pest in both storage and field ecosystems, particularly affecting maize crops across China. As chemical control methods face limitations due to resistance development and environmental concerns, biological control presents a promising alternative. In this study, [...] Read more.
Paralipsa gularis (Zeller) has become an increasingly destructive pest in both storage and field ecosystems, particularly affecting maize crops across China. As chemical control methods face limitations due to resistance development and environmental concerns, biological control presents a promising alternative. In this study, we isolated and identified a novel strain of Metarhizium sp. from naturally infected P. gularis larvae collected in Yunnan Province, China. Morphological characterization, along with ITS-rDNA and EF-1α-rDNA sequencing, confirmed the fungus as Metarhizium rileyi. The optimal growth medium for this strain was SMAY, and the optimal conditions were 25 °C under continuous light (L:D = 24:0). Laboratory bioassays showed that the strain exhibited high virulence against P. gularis larvae, with cumulative mortality reaching 82% following infestation with 5 × 108 conidia/mL. Biochemical analyses revealed that fungal infection significantly inhibited the activity of the key antioxidant enzyme SOD in the host, while activities of POD, CAT, and detoxification enzymes (P450, CarE, AChE, and GSTs) were significantly increased. These results indicate that immune responses were triggered, and systemic colonization of the host was achieved. Overall, this native M. rileyi strain demonstrates strong potential as an effective biological control agent. Its ability to overcome insect defenses and induce high mortality supports its integration into pest management programs targeting P. gularis. This work advances the understanding of fungal–insect interactions and contributes to sustainable, environmentally safe strategies for managing a pest of economic importance in agricultural ecosystems. Full article
(This article belongs to the Special Issue Insect Pathogens as Biocontrol Agents Against Pests)
Show Figures

Figure 1

14 pages, 1299 KB  
Article
Host-Dependent Variation in Tetranychus urticae Fitness and Microbiota Composition Across Strawberry Cultivars
by Xu Zhang, Hongjun Yang, Zhiming Yan, Yuanhua Wang, Quanzhi Wang, Shimei Huo, Zhan Chen, Jialong Cheng and Kun Yang
Insects 2025, 16(8), 767; https://doi.org/10.3390/insects16080767 - 25 Jul 2025
Cited by 2 | Viewed by 1450
Abstract
Tetranychus urticae, commonly known as the two-spotted spider mite, is a highly adaptable and polyphagous arthropod in the family Tetranychidae, capable of feeding on over 1200 plant species, including strawberries (Fragaria × ananassa Duch.). The fitness and microbiota of herbivorous arthropods [...] Read more.
Tetranychus urticae, commonly known as the two-spotted spider mite, is a highly adaptable and polyphagous arthropod in the family Tetranychidae, capable of feeding on over 1200 plant species, including strawberries (Fragaria × ananassa Duch.). The fitness and microbiota of herbivorous arthropods can vary significantly across different plant species and cultivars. In this study, we investigated the fecundity, longevity, growth rate, and microbiota composition of T. urticae reared on seven Chinese strawberry cultivars: Hongyan (HY), Yuexiu (YX), Tianshi (TS), Ningyu (NY), Xuetu (XT), Zhangjj (ZJ), and Xuelixiang (XLX). Our findings revealed significant differences among cultivars: mites reared on the XT cultivar exhibited the highest fecundity (166.56 ± 7.82 eggs), while those on XLX had the shortest pre-adult period (7.71 ± 0.13 days). Longevity was significantly extended in mites reared on XLX, XT, and NY cultivars (25.95–26.83 days). Microbiota analysis via 16S rRNA sequencing showed that Proteobacteria dominated (>89.96% abundance) across all mite groups, with Wolbachia as the predominant symbiont (89.58–99.19%). Male mites exhibited higher bacterial diversity (Shannon and Chao1 indices) than females, though Wolbachia abundance did not differ significantly between sexes or cultivars. Functional predictions highlighted roles of microbiota in biosynthesis, detoxification, and energy metabolism. These findings underscore the influence of host plant variety on T. urticae fitness and microbiota composition, suggesting potential strategies for breeding resistant strawberry cultivars and leveraging microbial interactions for pest management. Full article
(This article belongs to the Special Issue Insect Pathogens as Biocontrol Agents Against Pests)
Show Figures

Figure 1

Review

Jump to: Research

29 pages, 450 KB  
Review
A Global Review of the Pests and Diseases of Stingless Bees
by Robert McDougall, Robert Spooner-Hart and James Cook
Insects 2026, 17(6), 619; https://doi.org/10.3390/insects17060619 - 11 Jun 2026
Viewed by 49
Abstract
Managed pollinators are essential to agricultural productivity, but there are concerns that overreliance on western honey bees (Apis mellifera) places this productivity at risk. Stingless bees (Apidae; tribe Meliponini) can supplement or replace honey bees as pollinators in some warm climate [...] Read more.
Managed pollinators are essential to agricultural productivity, but there are concerns that overreliance on western honey bees (Apis mellifera) places this productivity at risk. Stingless bees (Apidae; tribe Meliponini) can supplement or replace honey bees as pollinators in some warm climate crops, but information is limited regarding the pests and diseases that they face. This paper reviews the existing research literature on the subject. We found 48 studies on arthropod pests and 28 on microbial diseases of stingless bees. There has been a relatively high research interest in mites (Acari) and small hive beetles (Aethina tumida); however, neither of these organisms are major pests of stingless bees. This high research interest likely results from their impact on honey bees and their novelty as newly arrived invasive species in many regions. Cleptoparasitic bees have also been highly researched. The most widely researched diseases were viruses. However, while many widespread honey bee viruses have been found in stingless bees, few studies examined whether these produced symptoms in stingless bees. For many suspected pests and pathogens, there is uncertainty regarding whether their relationship with hive collapse is causal or merely correlative. We conclude that pests and diseases of stingless bees are very under-researched compared to those of honey bees. This knowledge gap will need to be addressed if stingless bees are to serve an expanded role as managed agricultural pollinators. Full article
(This article belongs to the Special Issue Insect Pathogens as Biocontrol Agents Against Pests)
16 pages, 779 KB  
Review
Biological Control Strategies and Integrated Arthropod Pest Management for Camellia oleifera
by Yifei Xie, Jinxiu Yu, Wan Deng, Shaofeng Peng, Chi Li, Xuanye Wen, Wuhong Zhong and Mi Li
Insects 2025, 16(12), 1244; https://doi.org/10.3390/insects16121244 - 9 Dec 2025
Viewed by 1251
Abstract
Camellia oleifera, commonly known as oil-tea, serves as one of China’s most economically important oil crops. To ensure continued production yield and quality, biological control measures, operating within the framework of integrated pest management, have been extensively adopted nationwide. Integrated pest management [...] Read more.
Camellia oleifera, commonly known as oil-tea, serves as one of China’s most economically important oil crops. To ensure continued production yield and quality, biological control measures, operating within the framework of integrated pest management, have been extensively adopted nationwide. Integrated pest management facilitates effective management of arthropod pests afflicting C. oleifera by integrating biological control strategies with traditional chemical control methods. This approach significantly reduces the reliance on chemical pesticides and minimizes adverse environmental impacts. Over 600 natural enemy species targeting pests have been documented within the C. oleifera agroecosystems in China including approximately 38 viral agents along with 41 fungal, 166 parasitoid, 336 predator, and several bacterial species. Notably, both insectile natural enemies and fungal biopesticides derived from microbial resources are currently being used at scale in C. oleifera cultivation regions, serving as crucial alternatives to the use of conventional chemical pesticides. This paper comprehensively reviews recent progress in research and the application of synergistic integration of biological control with traditional pest management strategies for C. oleifera. The current status of research on natural enemy resources is analyzed and knowledge gaps in the domain of C. oleifera pest management are identified. Furthermore, future research trajectories are proposed that are intended to provide a scientific basis for the green and sustainable development of the C. oleifera industry. Full article
(This article belongs to the Special Issue Insect Pathogens as Biocontrol Agents Against Pests)
Show Figures

Figure 1

Back to TopTop