Future Pest Research Articles

Potential pesticide substrates of an insect ABCC transporter.

The use of synthetic pesticides carries a significant risk of pests developing resistance, leading to decreased pesticide effectiveness. ATP-binding cassette (ABC) transporters, especially the ABCC subfamily members, have been suggested to act as efflux pumps for various pesticides, thereby contributing to pesticide resistance. So far, the identification of potential pesticide substrates of insect ABC transporters is most often based on the quantification of transcript in arthropods. Here, we screened and identified the potential pesticide substrates of ABCC-9C from Tribolium castaneum based on an in vitro ATPase activity assay. Together with affinity evaluation-, cytotoxicity analysis-, and RNA interference-based bioactivity tests, we revealed that the insecticides, carbofuran, and buprofezin, are potential substrates of TcABCC-9C. Additionally, we identified an amphipathic translocation channel in the transmembrane domain of TcABCC-9C formed by 8 transmembrane helices. Molecular docking suggested that both carbofuran and buprofezin bind at the same site within the translocation channel via hydrophobic interactions. These findings indicate that TcABCC-9C might play a critical role in multi-pesticide resistance, providing a potential target for managing pesticide resistance and laying the groundwork for future pest control strategies. Given the conservations among ABCC subfamily members, the experimental model we developed in this study can be also applied to identify the potential substrates of other ABCC transporters, as well as to predict insecticide resistance mediated by ABCC transporters.

Impact of Key Insect Pests on Cowpea and their Relationship with Weather Parameters

Introduction: Cowpea (Vigna unguiculata L.) is a vital pulse crop with substantial nutritional value in India that faces production challenges due to various biotic and abiotic factors. Among the biotic factors that affects cowpea, pests such as Maruca vitrata and Riptortus pedestris significantly impact cowpea yields. This study aimed to evaluate the seasonal incidence of these pests and analyze their correlations with weather parameters in Thiruvananthapuram, Kerala. Methodology: Field observations were conducted over the cropping season to record pest populations across Standard Meteorological Weeks (SMWs). The population of the pod bugs and pod borers were taken from five plants. Statistical analyses were performed to identify correlations between pest incidence and key weather factors. Key Findings: The incidence of R. pedestris peaked in the 16th SMW, reaching 7.54 bugs per five plants. This pest displayed a significant positive correlation with maximum temperature (r = 0.637) and minimum temperature (r = 0.559) and a negative correlation with evening relative humidity (r =-0.480). Similarly, M. vitrata larval populations peaked during the same period at 2.65 larvae per five plants, showing a similar temperature-dependent correlation. Implications: The temperature-sensitive incidence patterns observed underscore the need for integrated pest management (IPM) strategies that address climatic factors to enhance cowpea sustainability. This data provides valuable insights for future pest forecasting and management efforts.

Identifying key monitoring areas for tree insect pest risks in China under climate change.

Climate change can exacerbate pest population growth, posing significant threats to ecosystem functions and services, social development, and food security. Risk assessment is a valuable tool for effective pest management that identifies potential pest expansion and ecosystem dispersal patterns. We applied a habitat suitability model coupled with priority protection planning software to determine key monitoring areas (KMA) for tree insect pest risks under climate change and used forest ecoregions and nature reserves to assess the ecological risk of insect pest invasion. Finally, we collated the prevention and control measures for reducing future pest invasions. The KMA for tree insect pests in our current and future climate is mainly concentrated in eastern and southern China. However, with climate change, the KMA gradually expands from southeastern to northeastern China. In the current and future climate scenarios, ecoregions requiring high monitoring levels were restricted to the eastern and southern coastal areas of China, and nature reserves requiring the highest monitoring levels were mainly distributed in southeastern China. Tree insect pest invasion assessment using ecoregions and nature reserves identified that future climates increase the risk of pest invasions in forest ecoregions and nature reserves, especially in northeastern China. The increased risk and severity of tree insect pest invasions require implementing monitoring and preventative measures in these areas. We effectively assessed the pest invasion risks using forest ecoregions and nature reserves under climate change. Our assessments suggest that monitoring and early prevention should focus on southeastern and northeastern China.

Hibernation changes tissue specific lipophilic profile of Chilo partellus (Swinhoe)

Chilo partellus undergo hibernation to survive under harsh winter conditions. We investigated changes in lipophilic profiles of larval and pupal whole body and tissues (haemolymph, fat bodies and integument) of hibernation and non-hibernation C. partellus strains. Significantly higher amount of lipids was found in whole body of pre-hibernation and hibernation larvae than non-hibernation larvae. At tissue level, total lipids were significantly higher in haemolymph and fat bodies of pre-hibernation, and integument of non-hibernation larvae. In whole body of larvae and pupae of hibernation and non-hibernation strains, most abundant fatty acids were oleic acid (16.4%–23%), palmitic acid (14.6%–19.3%), linoleic acid (9.3%–11.6%), palmitoleic acid (3.7%–7.3%) and stearic acid (1.7%–2.8%). Further, at tissue level, myristic, palmitoleic, palmitic, linoleic and oleic acids in fat bodies; and stearic acid in the integument of hibernation larvae were higher as compared to other body parts and larval stages of C. partellus. In pupal tissues, myristic, palmitic and stearic acids were higher in the haemolymph and fat bodies of non-hibernation pupae than post-hibernation pupae. Among the unsaturated fatty acids (UFAs), the palmitoleic acid significantly increased in all the larval tissues, and linoleic acid in fat bodies and integument, while oleic acid significantly decreased in integument of hibernation as compared to non-hibernation larvae of C. partellus. These information on adaptive remodelling of lipids at tissue level might help in future physiological, molecular, ecological and pest management studies on C. partellus.

Novel regulation pathway of eclosion hormones in Tribolium castaneum by distinct transcription factors through the initiation of 20-hydroxyecdysone

Eclosion hormone (EH) is not only a key trigger of insect ecdysis, but is also involved in the regulation of important physiological processes such as development, diapause, metamorphosis and reproduction. EH is an ideal target for RNAi treatment and prevention of the Tribolium castaneum. However, two EH genes in Tribolium castaneum demonstrate distinct replication and functional conversion relationships, and the mechanisms of transcriptional regulation of eclosion hormone remain largely unexplored and poorly understood. In this study, the activity of highly active promoter fragments and potential transcription factors of TcEH and TcEHL were identified using the Dual-Luciferase reporter system and TANSFAC. TcSlbo and TcCAD were revealed to be important transcription factors for TcEH and TcEHL, respectively. Knockdown of TcSlbo failed to slough off the old epidermis of Tribolium castaneum and prevented them from developing into adults. Furthermore, we demonstrated for the first time that 20-hydroxyecdysone (20E) affects the expression of TcEH and TcEHL by regulating the transcriptional activities of TcSlbo and TcCAD. This study provides new insights into the transcription regulation of TcEH and TcEHL, their roles in insect growth and development, and the involvement of 20E in eclosion regulation, offering potential molecular targets for future pest management strategies.

Insecticide binding mode analysis and biological effects of acetylcholinesterase target-site resistance mutations in Spodoptera frugiperda

It is urgent to solve insecticide resistance issues for fall armyworm (FAW), Spodoptera frugiperda. Some acetylcholinesterase-1 (Ace-1) mutations (A201S, G227A and F290V) have been identified as a cause of FAW resistance to organophosphates (OPs) and carbamates insecticides (CXs). However, the structural biological mechanisms on the relationship between the Ace-1 mutations and resistance to OPs and CXs still remain elusive. In this study, the A201S and F290V mutaions were found in eight fields populations of FAW except the G227A. Molecular docking revealed that the four Ace-1 proteins (Ace1-WT, Ace1-A201S, Ace1-G227A and Ace1-F290V) had the same binding modes and the same binding energies with acetylcholine (Ach), trichlorfon, chlorpyrifos, methomyl, carbaryl and chlorpyrifos oxide. The structural biological analysis revealed that the A201S mutations can enhance enzyme catalytic efficiency by introducing the hydroxyl group (-OH) from serine which performed the same function as the main-chain -NH and enhanced the interaction with the carboxy oxygen of acetylcholine (Ach), and the F290V mutation can effectively improve FAW resistance to insecticides by increasing the likelihood of Ach to enter the enzyme's active center for phenylalanine replaced by smaller valine under insecticide inhibition conditions. The bioassays and age-stage-specific life table analysis of FAW-SS and FAW-F290V populations revealed that F290V mutation effectively contributed to FAW resistance with a low fitness cost. This study provides a theoretical basis for future pest resistance management.

A GIS-coupled thermal response model for predicting the population growth potential of the red cotton bug, Dysdercus koenigii (Fabricius) (Hemiptera: Pyrrhocoridae) in India under climate change conditions

Recently, the red cotton bug has become a significant menace to cotton in India. With the potential for increased habitat suitability due to predicted temperature rise of 2.5 °C under future climate change in India, this pest could become even more severe in certain regions. Addressing the knowledge gap on the temperature-driven population growth of this pest is crucial for developing a climate-resilient pest management strategy. In this study, life history data gathered at various constant temperatures (15 °C–35 °C) were used to estimate temperature thresholds and thermal requirements for the red cotton bug development. Stochastic estimation of life table parameters and validation with real-time weather data were performed. The phenology model, integrated into a geographic information system, projected the future pest status based on SSP126 temperature change scenarios for the year 2050. The temperatures between 8.35 and 10.83 °C were estimated as lower developmental thresholds for various immature life stages. The optimum and upper threshold temperatures estimated for different life stages ranged between 22.14 – 28.32 °C and 35.80–39.08 °C, respectively. Thermal requirements of 447.97° days for life cycle completion were estimated. The optimum immature survival rates (>70%) were observed at temperatures between 25 and 30 °C. The temperature-dependent decrease in generation times from 90.45 days (15 °C) to 25.44 days (35 °C) was observed, whereas maximum fecundity was recorded at 32 °C. Simulation at fluctuating temperatures across different cotton growing locations provided reasonably similar results on potential population increase (finite rate of increase: 0.99–1.04 females/female/day and a generation time of 44.25–83.97 days). Risk mapping highlighted moderate to high suitability (ERI >0.4, GI > 6, and AI >4) of various cotton growing areas under current climate, and projected shifts in suitability under future climate change. The study has generated information valuable for implementing effective and timely pest management strategies for red cotton bug. Integrating the field observations with model outputs can enhance a practical understanding of red cotton bug dynamics.

Impact of leaf trichomes and stomatal density on the response of three soybean varieties to sucking pest infestation

Chemical pesticides disrupt local ecosystems, reduce populations of natural predators, and contribute to the evolution of pest resistance. Therefore, developing pest-resistant crop varieties is one of the most promising and environmentally friendly alternatives for pest control today. In the present study field experiments were conducted over two consecutive growing seasons in 2022 and 2023 to explore pest resistance among three soybean varieties viz. Crawford, Giza 111, and Giza 22. The research aimed to assess pest infestation resistance among these varieties, considering various leaf morphological factors. Four key pests were evaluated in the study viz. whiteflies (Bemisia tabaci Genn), spider mites (Tetranychus urticae Koc), aphids (Aphis gossypii Glover), and thrips (Thrips tabaci Lind)). The soybean varieties exhibited differences in susceptibility, and pest density varied across the two growing seasons. Crawford and Giza 111 demonstrated lower resistance, characterized by reduced leaf hair density and an increased number of stomata per leaflet. In contrast, Giza 22 was the most susceptible, featuring a higher density of trichomes and lower stomata density. In terms of field yield, Crawford produced the highest yield, followed by Giza 111, while Giza 22 yielded the least. The results of this study underscore the importance of selecting resistant plant varieties in future pest resistance improvement programs.

HCFormer: A Lightweight Pest Detection Model Combining CNN and ViT

Pests are widely distributed in nature, characterized by their small size, which, along with environmental factors such as lighting conditions, makes their identification challenging. A lightweight pest detection network, HCFormer, combining convolutional neural networks (CNNs) and a vision transformer (ViT) is proposed in this study. Data preprocessing is conducted using a bottleneck-structured convolutional network and a Stem module to reduce computational latency. CNNs with various kernel sizes capture local information at different scales, while the ViT network’s attention mechanism and global feature extraction enhance pest feature representation. A down-sampling method reduces the input image size, decreasing computational load and preventing overfitting while enhancing model robustness. Improved attention mechanisms effectively capture feature relationships, balancing detection accuracy and speed. The experimental results show that HCFormer achieves 98.17% accuracy, 91.98% recall, and a mean average precision (mAP) of 90.57%. Compared with SENet, CrossViT, and YOLOv8, HCFormer improves the average accuracy by 7.85%, 2.01%, and 3.55%, respectively, outperforming the overall mainstream detection models. Ablation experiments indicate that the model’s parameter count is 26.5 M, demonstrating advantages in lightweight design and detection accuracy. HCFormer’s efficiency and flexibility in deployment, combined with its high detection accuracy and precise classification, make it a valuable tool for identifying and classifying crop pests in complex environments, providing essential guidance for future pest monitoring and control.

Phytochemical Characterization, Fumigant and Contact Toxicity Activities of Four Essential Oils Against Eriophyid Gall Mite, Aceria pongamiae Keifer (Acarina: Eriophyidae).

Plant-derived essential oils (EO) offer a natural alternative to chemical pesticides for eco-friendly pest control approaches. Aceria pongamiae Keifer, a notorious pest that affects Pongamia pinnata (L.) Pierre has mainly been controlled using synthetic acaricides leading to resistance development and environmental issues. EOs provide a natural and biodegradable option for pest control, with a unique mode of action. This study evaluates the acaricidal efficacy of EOs-eucalyptus Eucalyptus maculata Hook (EEO), lavender Lavandula angustifola L. (LEO), peppermint Mentha piperita L. (PEO), and black pepper Piper nigrum L. (BPEO) against A. pongamiae for the first time. We investigated the biological activity of EOs using fumigation and contact toxicity assays at concentrations ranging from 0.1 to 1 % and 0.6 to 0.9 % respectively, overexposure periods of 24, 48 and 72 h. Chemical characterization of EOs was performed using GC-MS analysis. Eucalyptol (62.88 %), linalyl acetate (39.11 %), menthol (44.35 %), and caryophyllene (32.77 %) were the main components of EEO, LEO, PEO and BPEO respectively. After 24 h of observation, EEO (LC50=1.01 %) and after 48 and 72 h, PEO had the highest fumigant toxicity (LC50=0.71 and 0.29 % respectively). The BPEO showed the most contact toxicity after 24, 48 and 72 h (LC50=0.92, 0.68 and 0.46 % respectively). This work reinforces the selection of adequate essential oils for implementation in future pest control strategies.

Bioactivity of silverleaf nightshade (Solanum elaeagnifolium Cav.) berries parts against Galleria mellonella and Erwinia carotovora and LC-MS chemical profile of its potential extract

Natural products received much attention as an environmentally beneficial solution for pest management. Therefore, the extracts of invasive silverleaf nightshade (Solanum elaeagnifolium Cav.) weeds using their berries parts (seeds, peels and mucilage) supported by bioassay-guided fractionation were tested against both the greater wax moth (Galleria mellonella) and Erwinia carotovora pv. carotovora causes of the blackleg of potatoes. The seeds and peels of S. elaeagnifolium were successively extracted by maceration using dichloromethane (DCM), ethyl acetate (EtOAc), and ethanol (EtOH), respectively. While, its mucilage was extracted using EtOAc. The successive EtOH extract of the plant seeds had promising inhibition efficacy and the best minimal inhibition concentration (MIC) of 50 µg/ml against E. Carotovora amongst other extracts (DCM and EtOAc of the plant berries parts). Depending on dose response activity, EtOH extract had G. mellonella larval mortality and pupal duration rates (LC50; 198.30 and LC95; 1294.73 µg/ml), respectively. Additionally, this EtOH extract of seeds was fractionated using preparative TLC to three characteristic bands. The insecticidal and bacterial activities of these isolated bands (SEA, SEB, and SEC) were evaluated at a dose of 100 µg/ml, causing mortality by 48.48, 62.63 and 92.93% (G. mellonella larvae) and inhibition by 15.22, 0.00 and 31.66 mm (E. carotovora), respectively. Moreover, the separated major three bands were tentatively identified using LC-ESI-MS analysis revealing the presence of two phenolic acids; chlorogenic acid (SEA) and dicaffeoyl quinic acid (SEB) in addition to one steroidal saponin (SEC) annotated as borassoside E or yamoscin. Finally, the plant seeds’ successive EtOH extract as well as its active constituents, exhibited potential broad-spectrum activity and the ability to participate in future pest management initiatives. A field study is also recommended to validate its bio-efficacy against selected pests and to develop its formulations.

Functional analysis of novel cystatins from Haemaphysalis doenitzi and evaluation of their roles in cypermethrin and λ-cyhalothrin resistance

Currently, the primary strategy for tick control relies on chemical agents. Pyrethrins, which are botanically derived compounds, have demonstrated efficacy in controlling ticks without posing a risk to human or animal health. However, research into pyrethrins' metabolic mechanisms remains sparse. Cystatin, as a reversible binding inhibitor of cysteine protease, may be involved in the initiation of pyrethrin detoxification of Haemaphysalis doenitzi. In this study, two novel cystatins were cloned, HDcyst-3 and HDcyst-4, the relative expression of which was highest in the Malpighian tubules compared with the tick midguts, salivary glands, and ovaries. Prokaryotic expression and in vitro studies revealed that cystatins effectively inhibit the enzymatic activities of cathepsins B and S. RNAi results showed that the reduction of cystatins significantly decreased the engorgement weight, egg mass weight, and egg hatching rate of adult female ticks, and prolonged feeding time by two days. The control rate of rHDcyst-3 and rHDcyst-4 protein vaccination against female adults were 55.9% and 63.2%, respectively. In addition, the tick immersion test showed that cypermethrin and λ-cyhalothrin had significant acaricidal effects against adult unfed H. doenitzi. The qPCR result indicated that compared with the control group, the expression of HDcyst-3 and HDcyst-4 was markedly decreased in the sublethal cypermethrin and λ-cyhalothrin group at LC50. Enzyme activity showed that cypermethrin and λ-cyhalothrin could significantly induce the activities of glutathione S-transferase (GST), carboxylesterase (CarE), and acetylcholinesterase (AchE). The aforementioned results provided indirect evidence that cystatin plays an important role in pyrethrin detoxification and provides a theoretical basis for future acaricide experiments and pest management.

Non-choice vs. Free-choice: when and how Cydnoseius negevi (Swirski and Amitai) female attack its prey?

BackgroundCydnoseius negevi (Swirski and Amitai) (Acari: Phytoseiidae) is a promising bio-agent in the Mediterranean region. It attacks a wide range of pest species. Two fundamental questions have been raised when C. negevi was a promising candidate for biological control applications in a hydroponic system. This study was carried out to answer the raised questions: (1) how long a predatory female takes to attack its prey in a non-choice biological control application? and (2) what do the predatory females prefer when offered a multiple choice (free-choice) of pest preys?, to understand the potentialities of C. negevi attacking behaviour.ResultsTwo sets of experiments were conducted for 240 min under laboratory conditions of 27 ± 2 °C, 60 ± 5% RH, and 18:6h L:D photoperiod. The tested prey species were Tetranychus urticae Koch, Bemisia tabaci (Gennadius), Frankliniella occidentalis (Pergande), Parlatoria ziziphi (Lucas), and Icerya aegyptiaca (Douglas). Non-choice experiments tested the time (min) needed to the 24 h starved female to attack its prey. The free-choice experiments tested the female’ choices and the time recorded for each female during the full experimental time. Significant differences were recorded in both sets at confidence level of 95%. The spider mite T. urticae recorded the shortest predatory female’s response in both non- and free-choice sets. On the contrary, the insect I. aegyptiaca had the least female’s choice in both sets of experiment.ConclusionThe present study discussed the behavioural categories of C. negevi. The female responses showed a list of priorities to the tested herbivore species. Such behavioural simulation is considerable for the future pest control applications to predict the generalist predator’s preferences among a wide range of multiple herbivore species.

Combining biological control approaches for managing insect crop pests in the field can generate interactive effects

Abstract With the loss of effective chemical controls of crop pests, a move towards biological controls is a way to future‐proof our agricultural system. Floral field margins have shown successes in reducing crop pests, though the effect may not be precise enough to control infestations in commercial crops. Entomopathogenic nematodes (EPNs) may provide a more species‐ and time‐specific control and combining these methods may have synergy. Three in‐field vegetation margins, divided into four plots each (two floral and two grass), were established in March 2022. Three strips of sprouting broccoli were planted parallel in April, May and June. Each strip had a split‐plot design, with eight replicates of four nematode treatments placed alongside each floral/grass plot: Steinernema carpocapsae, S. feltiae and Heterorhabditis bacteriophora and a nematode‐free control. Pest pressure was assessed using adult counts. Assessments of crop yield and crop damage associated specifically with the swede smidge (Contarinia nasturtii) were also made. It was found that utilising a combination of control measures was successful in controlling a wider range of pests, though the success of each control method was highly dependent on the time of crop plantings. Field margins had a significant influence on crop damage associated with the swede midge. The EPN H. bacteriophora was an effective control method for the cabbage stem flea beetle and the swede midge, as well as reducing crop damage and yield loss. Field margins and EPNs combined have an interactive effect on crop yield, highlighting the need for control methods to be tested in combination in future integrated pest management research to accurately understand their effects within an integrated system.

Effects of Conventional and Organic Fertilization on the Chemical Profile of Sorghum bicolor and the Preference of Sugarcane Aphids (Melanaphis sacchari)

Melanaphis sacchari is a cosmopolitan pest that causes losses in sorghum crops, so new management methods are needed. In addition, the type of fertilization used influences plant compositions and pest infestation, and allelochemicals are a promising method for the possible management of M. sacchari. In this work, we measured the preference of M. sacchari through chemical stimuli towards sorghum plants grown under greenhouse conditions without fertilization (F0), conventional fertilization (CF), and organic fertilization (OF). Leaves were collected from sorghum plants fertilized with 200 kg N ha−1 using ammonium sulfate and poultry manure. Extracts were obtained using Soxhlet extraction, and the compounds were identified using a gas chromatograph coupled with mass spectrometry (GC-MS). Sorghum extracts were individually tested through bioassays to determine M. sacchari preference. The abundance and number of compounds in sorghum differed depending on the type of fertilization used. M. sacchari showed a preference for the extract from CF sorghum plants (76.66%) over the extract from OF plants (23.34%). Therefore, the type of fertilization can be used as a tactic to prevent higher infestations of M. sacchari. The biological activity of the compounds identified here with M. sacchari should be determined for future pest management strategies using allelochemicals, given that the sugarcane aphid uses chemical signals to locate its host plant.

Pest management facing warming and chemical stresses: Multi-stress effects on the biological agent Trichogramma oleae

Global change is affecting plant-insect interactions in agroecosystems and can have dramatic consequences on yields when causing non-targeted pest outbreaks and threatening the use of pest natural enemies for biocontrol. The vineyard agroecosystem is an interesting system to study multi-stress conditions: on the one hand, agricultural intensification comes with high inputs of copper-based fungicides and, on the other hand, temperatures are rising due to climate change. We investigated interactive and bottom-up effects of both temperature increase and copper-based fungicides exposure on the important Lepidopteran vineyard pest Lobesia botrana and its natural enemy, the oophagous parasitoid Trichogramma oleae. We exposed L. botrana larvae to three increasing copper sulfate concentrations under two fluctuating thermal regimes, one current and one future. Eggs produced by L. botrana were then exposed to T. oleae. Our results showed that the survival of L. botrana, was only reduced by the highest copper sulfate concentration and improved under the warmer regime. The development time of L. botrana was strongly reduced by the warmer regime but increased with increasing copper sulfate concentrations, whereas pupal mass was reduced by both thermal regime and copper sulfate. T. oleae F1 emergence rate was reduced and their development time increased by combined effects of the warmer regime and increasing copper sulfate concentrations. Size, longevity and fecundity of T. oleae F1 decreased with high copper sulfate concentrations. These effects on the moth pest and its natural enemy are probably the result of trade-offs between the survival and the development of L. botrana facing multi-stress conditions and implicate potential consequences for future biological pest control. Our study supplies valuable data on how the interaction between pests and biological control agents is affected by multi-stress conditions.

How Climate Warming Influences the Phenology of Grapholita molesta (Busck, 1916) (Lepidoptera: Tortricidae) in China: Insight from Long-Term Historical Data.

Grapholita molesta (Busck, 1916), a significant pest affecting various fruits such as pears, apples, peaches, etc., is highly adaptable to changing temperatures. However, the phenological response mechanism of this pest to climate warming remains unclear. To address this issue, we collected population dynamics data of G. molesta in China over the years along with corresponding climate data. We analyzed five phenological indexes: the first, end, and peak occurrence dates of contemporary adults as well as the first and peak occurrence dates of overwintering adults in China. Results revealed an upward trend in the annual average temperature and average temperature of the four seasons in regions infested by G. molesta in eastern, northeastern, northwestern, northern, and southwestern China from 1980 to 2020. Notably, the population peak date of overwintering adults in northeastern and eastern China significantly advanced along with the first occurrence date and the population peak date of overwintering adults in northern China. Additionally, the population peak date of contemporary adults in northwestern China significantly advanced. However, the end occurrence date of contemporary adults in northern China was significantly delayed, as was the first occurrence date of overwintering adults in northwestern China. Furthermore, our study demonstrated spatial heterogeneity in the phenological response of G. molesta to climate warming across China. This study elucidates the phenological response of G. molesta to climate warming, offering valuable insights for predicting future pest infestations and informing adaptive pest management strategies in fruit tree cultivation.

Immobilization of Bacillus thuringiensis Cry1Ac in metal-organic frameworks through biomimetic mineralization for sustainable pest management

Traditional chemical pesticide dosage forms and crude application methods have resulted in low pesticide utilization, increased environmental pollution, and the development of resistance. Compared to traditional pesticides, nanopesticides enhance the efficiency of pesticide utilization and reduce the quantity required, thereby decreasing environmental pollution. Herein, Cry1Ac insecticidal crystal protein from Bacillus thuringiensis Subsp. Kurstaki HD-73 was encapsulated in a metal-organic framework (zeolite imidazolate framework-8, ZIF-8) through biomimetic mineralization to obtain Cry1Ac@ZIF-8 nanopesticides. The Cry1Ac@ZIF-8 nanopesticides exhibited a dodecahedral porous structure, and the introduction of Cry1Ac did not affect the intrinsic crystal structure of ZIF-8. The indoor toxicity analysis revealed that the toxicity of Cry1Ac towards Ostrinia furnacalis (Guenée), Helicoverpa armigera Hubner, and Spodoptera litura Fabricius was not affected by ZIF-8 encapsulation. Surprisingly, Cry1Ac@ZIF-8 still exhibited excellent pest management efficacy even after exposure to heat, UV irradiation, and long-term storage. More importantly, the encapsulation of ZIF-8 significantly enhanced the internal absorption performance of Cry1Ac in maize leaves and extended its persistence period. Thus, ZIF-8 could potentially serve as a promising carrier for the preparation of nanopesticides with enhanced applicability, stability, and persistence period, providing a powerful strategy to improve the application of Cry1Ac in future agricultural pest management.

Isolation and Identification of Entomopathogenic Fungi from the Soils of Northwest Iran and their Biological Control Efficacy on the Flour Moth (Ephestia kuehniella)

Entomopathogenic fungi have the potential to serve as alternatives to or supplements for chemical pesticides in insect biocontrol, with many of these fungi being utilized in commercial and integrated pest control practices globally. This study aimed to isolate and evaluate the efficacy of various entomopathogenic fungi for the biocontrol of the flour moth, Ephestia kuehniella (Lep: Pyralidae). Multiple isolates of entomopathogenic fungi were acquired from soils across different districts of Azerbaijan province in northwest Iran, and their virulence against E. kuehniella larvae was assessed. Seventeen isolates representing diverse entomopathogenic fungi were isolated and purified using the soil trap method from 20 distinct soil samples. Their pathogenicity against E. kuehniella was evaluated in three replicates through the immersion technique at concentrations of 104, 105, 106, 107, and 108 conidia/mL. Identification of selected fungal isolates was based on morphological features, mycological parameters, and sequencing of the internal transcribed spacer (ITS) region. The study identified seven fungal species, namely Lecanicillium lecanii, Beauveria bassiana, Metarhizium anisopliae, Purpureocillium lilacinum, Aspergillus oryzae, Penicillium citrinum, and Aspergillus lavus, among the 17 isolates collected. Bioassay assessments revealed the susceptibility of 4th-instar larvae of E. kuehniella to the selected isolates, with the larval mortality rate increasing with higher conidial concentrations. A. lavus, A. oryzae, P. citrinum, and P. lilacinum exhibited maximum virulence, causing nearly 90% lethality, while Metarhizium anisopliae demonstrated the lowest level of virulence, resulting in approximately 30% lethality in E. kuehniella. The virulence pattern of isolates across different concentrations was notably distinct. The findings of this research demonstrate that entomopathogenic fungi isolated in this investigation could be effectively incorporated into future pest management programs.

Chitinase Producing Gut-Associated Bacteria Affected the Survivability of the Insect Spodoptera frugiperda.

Fall armyworm (Spodoptera frugiperda) is a highly destructive maize pest that significantly threatens agricultural productivity. Existing control methods, such as chemical insecticides and entomopathogens, lack effectiveness, necessitating alternative approaches. Gut-associated bacteria were isolated from the gut samples of fall armyworm and screened based on their chitinase and protease-producing ability before characterization through 16S rRNA gene sequence analysis. The efficient chitinase-producing Bacillus licheniformis FGE4 and Enterobacter cloacae FGE18 were chosen to test the biocontrol efficacy. As their respective cell suspensions and extracted crude chitinase enzyme, these two isolates were applied topically on the larvae, supplemented with their feed, and analyzed for their quantitative food use efficiency and survivability. Twenty-one high chitinase and protease-producing bacterial isolates were chosen. Five genera were identified by 16S rRNA gene sequencing: Enterobacter, Enterococcus, Bacillus, Pantoea, and Kocuria. In the biocontrol efficacy test, the consumption index and relative growth rate were lowered in larvae treated with Enterobacter cloacae FGE18 by topical application and feed supplementation. Similarly, topical treatment of Bacillus licheniformis FGE4 to larvae decreased consumption index, relative growth rate, conversion efficiency of ingested food, and digested food values. The presence of gut bacteria with high chitinase activity negatively affects insect health. Utilizing gut-derived bacterial isolates with specific insecticidal traits offers a promising avenue to control fall armyworms. This research suggests a potential strategy for future pest management.