Management Of Pest Populations Research Articles

Integrated Pest Management Precision: Harnessing the Joint Influence of Entomopathogenic Fungi, Nematodes, and Chlorantraniliprole for Targeted Control of Fall Armyworm (Spodoptera Frugiperda)

Background: The Spodoptera frugiperda, commonly known as the fall armyworm (FAW), is a significant pest impacting agricultural productivity worldwide. Originating from tropical and subtropical regions, FAW has shown a high capacity for migration and destruction across a wide variety of crops. Integrated Pest Management (IPM) strategies offer sustainable approaches to managing pest populations, minimizing environmental impact, and reducing reliance on chemical insecticides. Objective: This study aimed to evaluate the efficacy of combining biological control agents, specifically Heterorhabditis bacteriophora (Hb) and Beauveria bassiana (Bb), with the chemical insecticide chlorantraniliprole (Ch) against third and fifth instar larvae of S. frugiperda. The study sought to determine the potential synergistic effects of these combinations on larval mortality and developmental disruption. Methods: The research encompassed laboratory bioassays, greenhouse, and field trials to assess the impact of the biocontrol agents and chlorantraniliprole, both individually and in combination, on FAW larval mortality and development. Larval populations of S. frugiperda were collected and reared under controlled conditions. Treatments applied included Hb, Bb, Ch, Hb+Bb, Hb+Ch, Bb+Ch, and Hb+Bb+Ch. Mortality rates were recorded at 3, 5, and 7 days post-treatment, while developmental parameters were assessed through pupation rates, adult emergence, and egg eclosion percentages. Results: The combined application of Hb, Bb, and Ch significantly increased mortality rates in both the third and fifth instar larvae compared to individual treatments, with the highest mortality observed in the Hb+Bb+Ch group (100% by day 7). Developmental disruptions were also noted, including reduced pupation rates, adult emergence, and egg eclosion, particularly in treatments involving the combined use of biocontrol agents and chlorantraniliprole. Statistical analysis confirmed the significance of these findings (P<0.01). Conclusion: The integration of Hb, Bb, and Ch presents a viable IPM strategy for effectively managing S. frugiperda populations. This combination not only enhances larval mortality but also disrupts developmental stages, offering a potential reduction in FAW infestation levels and associated crop damages. These results underscore the importance of adopting sustainable pest management practices that leverage synergistic effects between biological and chemical agents.

Insect Pests in Agriculture Identifying and Overcoming Challenges through IPM

Insect pests pose significant challenges to agricultural production worldwide, threatening food security and economic stability. Integrated Pest Management (IPM) offers a comprehensive approach to address these challenges sustainably. This abstract explores the principles and strategies of IPM, emphasizing its focus on minimizing environmental impacts and reducing reliance on chemical pesticides. Through biological control, cultural practices, mechanical control, and selective pesticide use, IPM aims to manage pest populations effectively while promoting biodiversity and long-term agricultural sustainability. By implementing IPM strategies, farmers can mitigate the impact of insect pests while fostering resilient and productive agricultural systems.
 Insect pests pose a significant threat to agricultural productivity worldwide. They can devastate crops, leading to substantial economic losses and threatening food security. Identifying and managing these pests effectively is crucial for sustainable agriculture. Integrated Pest Management (IPM) offers a comprehensive approach to address insect pest challenges while minimizing environmental impacts and reliance on chemical pesticides. Insect pests represent a persistent threat to agricultural productivity and food security globally. This abstract delves into the principles and practices of Integrated Pest Management (IPM) as a sustainable approach to address these challenges. IPM integrates various strategies, including biological control, cultural practices, mechanical control, and selective pesticide use, to manage pest populations effectively while minimizing environmental harm. By emphasizing monitoring, threshold levels, and selective interventions, IPM promotes the judicious use of pesticides and fosters ecosystem resilience. The abstract underscores the importance of IPM in promoting biodiversity, reducing chemical inputs, and ensuring the long-term sustainability of agricultural systems. Through the adoption of IPM principles, farmers can mitigate the impacts of insect pests while advancing environmentally conscious and economically viable agricultural practices.

Toxicity of Two Plant Essential Oils as Eco-friendly Fumigants against the Red Flour Beetle Tribolium castaneum

Background: This study aims to extract essential oils from Artemisia herba alba and Eucalyptus camaldolensis plants and evaluate their effectiveness as eco-friendly natural fumigants against larvae and adults of red flour beetle Tribolium castaneum. Methods: The current study was conducted under laboratory conditions for the period from 2023-4 to 2023-8 in the Plant Protection Laboratory in the Diyala Agriculture Directorate, Iraq. Different concentrations of 2, 4, 6, 8 and 10 µL-1 air for exposure period of 24, 48 and 72 hours. Result: Larval mortality rates reached 100% at concentrations of 8 and 10 µL L-1 air for Eucalyptus and Artemisia, respectively. The mortality rate increases with increasing concentration in adults, where the highest killing rate was recorded at 8.10 µL L-1 air, reaching 90% and 100% for Artemisia, while it reached 96.6% and 100% for Eucalyptus, respectively. Mortality rates were high throughout the duration of the first exposure and these rates increased as the exposure period increased to 48 hours and 72 hours, with the next highest killing rates for concentrations of 6, 8 and 10 µL L-1 air for Artemisia and Eucalyptus oils. There was no significant difference with pesticide treatment. This indicates the possibility of using essential oils in the applied field to manage pest populations in store products.

ASSESSING THE EFFICACY OF ECO-FRIENDLY INSECTICIDES AGAINST THE SPODOPTERA LITURA (TOBACCO CUTWORM) POPULATION

In the investigation conducted, the assessment of environmentally friendly insecticides, including Abamectin, Spinosad, Insect Growth Regulators (IGRs), and Bacillus thuringiensis, was undertaken with a focus on evaluating their efficacy and toxicity in controlling the tobacco cutworm, Spodoptera litura. The study aimed to provide insights into the ecological compatibility of these insecticides within the context of controlling the target pest. Among the various treatment applications, Diflubenzuron + Deltamethrin exhibited the highest efficacy in causing mortality among the larvae of the cutworm and Abamectin demonstrated significant approachability, resulting in mortality rates of 91.35% and 91.23%, respectively. The untreated control group exhibited the highest growth rate, while treatment with Diflubenzuron + Deltamethrin yielded the lowest growth rate at 2.03. Bacillus thuringiensis treatment demonstrated significant impacts on both larval-pupal transition and survival rates, registering values of 1.34 and 0.43, respectively. This indicates a notable influence on the developmental stages and overall survival of Spodoptera litura larvae. The findings of this study underscore the potential of eco-compatible pesticides, with Diflubenzuron + Deltamethrin, Abamectin, and Bacillus thuringiensis presenting distinct outcomes in the control of Spodoptera litura. The observed effects on mortality, growth rates, and developmental transitions provide valuable insights into the practical applicability of these environmentally friendly insecticides in managing pest populations in an ecologically sustainable manner.

Understanding Farmers' Knowledge, Attitude, and Practices in Managing Water Quality for Effective Insecticide Performance: A Case Study in Agriculture

Pesticides are frequently used in agriculture to manage pest populations below threshold levels, but their application usually does not get the desired outcome. There are many factors for the low performance of pesticides, with water quality being one of them. Local farmers from Sindh, Pakistan, have little or no knowledge about the role of water quality in the performance of pesticides. Therefore, a survey study was conducted to determine the farmer’s knowledge, attitude, and practice regarding it. Ten villages were selected from the Hyderabad and Tando Allahyar districts, and the information was obtained from five farmers from each village. Descriptive analysis results indicated that most respondents prefer to grow cotton (average 24.07 acres), with the majority being illiterate (54 %), averaging 39.74 years of age and 18.80 years of farming experience. Most farmers (92 %) used groundwater for spray solution, whereas only 3 % tested the water in their fields. The majority (74.51 %) of farmers considered lower-quality pesticides for their poor performance. Therefore, farmers normally apply up to sixteen sprays to control pests. It was also observed that although farmers have knowledge about the role of water quality in the performance of pesticides to get pest control, they lack the attitude and practice in their field. Therefore, it is suggested that awareness should be created among the local farmers regarding water quality to be used in spray solutions to get desired pest control.

Integrated behavior and transcriptomic analysis provide valuable insights into the response mechanisms of Dastarcus helophoroides Fairmaire to light exposure.

Light traps have been widely used to monitor and manage pest populations, but natural enemies are also influenced. The Dastarcus helophoroides Fairmaire is an important species of natural enemy for longhorn beetles. However, the molecular mechanism of D. helophoroides in response to light exposure is still scarce. Here, integrated behavioral, comparative transcriptome and weighted gene co-expression network analyses were applied to investigate gene expression profiles in the head of D. helophoroides at different light exposure time. The results showed that the phototactic response rates of adults were 1.67%-22.5% and females and males displayed a negative phototaxis under different light exposure [6.31 × 1018 (photos/m2/s)]; the trapping rates of female and male were influenced significantly by light exposure time, diel rhythm, and light wavelength in the behavioral data. Furthermore, transcriptome data showed that a total of 1,052 significantly differentially expressed genes (DEGs) were identified under different light exposure times relative to dark adaptation. Bioinformatics analyses revealed that the "ECM-receptor interaction," "focal adhesion," "PI3K-Akt signaling," and "lysosome" pathways were significantly downregulated with increasing light exposure time. Furthermore, nine DEGs were identified as hub genes using WGCNA analysis. The results revealed molecular mechanism in negative phototactic behavior response of D. helophoroides under the light exposure with relative high intensity, and provided valuable insights into the underlying molecular response mechanism of nocturnal beetles to light stress.

Altered Gene Expression of the Parasitoid Pteromalus puparum after Entomopathogenic Fungus Beauveria bassiana Infection

Both parasitoids and entomopathogenic fungi are becoming increasingly crucial for managing pest populations. Therefore, it is essential to carefully consider the potential impact of entomopathogenic fungi on parasitoids due to their widespread pathogenicity and the possible overlap between these biological control tools during field applications. However, despite their importance, little research has been conducted on the pathogenicity of entomopathogenic fungi on parasitoids. In our study, we aimed to address this knowledge gap by investigating the interaction between the well-known entomopathogenic fungus Beauveria bassiana, and the pupal endoparasitoid Pteromalus puparum. Our results demonstrated that the presence of B. bassiana significantly affected the survival rates of P. puparum under laboratory conditions. The pathogenicity of B. bassiana on P. puparum was dose- and time-dependent, as determined via through surface spraying or oral ingestion. RNA-Seq analysis revealed that the immune system plays a primary and crucial role in defending against B. bassiana. Notably, several upregulated differentially expressed genes (DEGs) involved in the Toll and IMD pathways, which are key components of the insect immune system, and antimicrobial peptides were rapidly induced during both the early and late stages of infection. In contrast, a majority of genes involved in the activation of prophenoloxidase and antioxidant mechanisms were downregulated. Additionally, we identified downregulated DEGs related to cuticle formation, olfactory mechanisms, and detoxification processes. In summary, our study provides valuable insights into the interactions between P. puparum and B. bassiana, shedding light on the changes in gene expression during fungal infection. These findings have significant implications for the development of more effective and sustainable strategies for pest management in agriculture.

Discovery of Insect Attractants Based on the Functional Analyses of Female-Biased Odorant Receptors and Their Orthologs in Two Closely Related Species.

Olfaction plays an instrumental role in host plant selection by phytophagous insects. Helicoverpa assulta and Helicoverpa armigera are two closely related moth species with different host plant ranges. In this study, we first comparatively analyzed the function of 11 female-biased odorant receptors (ORs) and their orthologs in the two species by the Drosophila T1 neuron expression system and then examined the electroantennography responses of the two species to the most effective OR ligands. Behavioral assays using a Y-tube olfactometer indicate that guaiene, the primary ligand of HassOR21-2 and HarmOR21-2, only attracts the females, while benzyl acetone, the main ligand of HassOR35 and HarmOR35, attracts both sexes of the two species. Oviposition preference experiments further confirm that guaiene and benzyl acetone are potent oviposition attractants for the mated females of both species. These findings deepen our understanding of the olfactory coding mechanisms of host plant selection in herbivorous insects and provide valuable attractants for managing pest populations.

A deep learning-based pipeline for whitefly pest abundance estimation on chromotropic sticky traps

Integrated Pest Management (IPM) is an essential approach used in smart agriculture to manage pest populations and sustainably optimize crop production. One of the cornerstones underlying IPM solutions is pest monitoring, a practice often performed by farm owners by using chromotropic sticky traps placed on insect hot spots to gauge pest population densities. In this paper, we propose a modular model-agnostic deep learning-based counting pipeline for estimating the number of insects present in pictures of chromotropic sticky traps, thus reducing the need for manual trap inspections and minimizing human effort. Additionally, our solution generates a set of raw positions of the counted insects and confidence scores expressing their reliability, allowing practitioners to filter out unreliable predictions. We train and assess our technique by exploiting PST - Pest Sticky Traps, a new collection of dot-annotated images we created on purpose and we publicly release, suitable for counting whiteflies. Experimental evaluation shows that our proposed counting strategy can be a valuable Artificial Intelligence-based tool to help farm owners to control pest outbreaks and prevent crop damages effectively. Specifically, our solution achieves an average counting error of approximately 9% compared to human capabilities requiring a matter of seconds, a large improvement respecting the time-intensive process of manual human inspections, which often take hours or even days.

Enhancing Crop Protection and Yield through Precision Agriculture and Integrated Pest Management: A Comprehensive Review

The increasing global population has intensified the necessity for sustainable and efficient agricultural practices. One promising avenue for meeting this demand is the synergy between Precision Agriculture (PA) and Integrated Pest Management (IPM). This review paper aims to scrutinize the multifaceted relationship between PA and IPM in augmenting crop protection and yield. Utilizing a comprehensive analysis of existing literature, the study elucidates how cutting-edge technologies in PA, such as drone imaging and soil sensor networks, can be harmoniously integrated with IPM strategies. These encompass biological, chemical, and cultural tactics to manage pest populations and mitigate damage, thereby fostering an environment conducive to optimal crop growth. The review identifies that the confluence of PA and IPM not only enhances the efficiency of resource use but also mitigates the environmental footprint of agricultural activities. Moreover, we delve into case studies that demonstrate significant yield improvements and cost reductions, underscoring the economic viability of integrating PA and IPM. The findings highlight the transformative potential of marrying these two domains, suggesting that such integration could be a cornerstone in the future of sustainable agriculture. The paper concludes by outlining research gaps and proposing avenues for future studies, emphasizing the need for multi-disciplinary approaches to fully unlock the potential of this integration.

Microbiome analysis of Spodoptera frugiperda (Lepidoptera, Noctuidae) larvae exposed to Bacillus thuringiensis (Bt) endotoxins.

Spodoptera frugiperda (or fall armyworm, FAW) is a polyphagous pest native to Western Hemisphere and recently discovered in the Eastern Hemisphere. In Colombia, S. frugiperda is recognized as a pest of economic importance in corn. The species has genetically differentiated into two host populations named "corn" and "rice" strains. In 2012, a study made in central Colombia demonstrated that the corn strain is less susceptible to Bacillus thuringiensis (Bt) endotoxins (Cry1Ac and Cry 1Ab) than the rice strain. In this country, Bt transgenic corn has been extensively produced over the last 15 years. Since gut microbiota plays a role in the physiology and immunity of insects, and has been implicated in promoting the insecticidal activity of Bt, in this study an analysis of the interaction between Bt endotoxins and FAW gut microbiota was made. Also, the detection of endosymbionts was performed here, as they might have important implications in the biological control of a pest. The composition and diversity of microbiomes associated with larval specimens of S. frugiperda(corn strain) was investigated in a bioassay based on six treatments in the presence/absence of Bt toxins and antibiotics (Ab) through bacterial isolate analyses and by high throughput sequencing of the bacterial 16S rRNA gene. Additionally, species specific primers were used, to detect endosymbionts from gonads in S. frugiperda corn strain. Firmicutes, Proteobacteria and Bacteroidota were the most dominant bacterial phyla found in S. frugiperda corn strain. No significant differences in bacteria species diversity and richness among the six treatments were found. Two species of Enterococcus spp., E. mundtii and E. casseliflavus were detected in treatments with Bt and antibiotics, suggesting that they are less susceptible to both of them. Additionally, the endosymbiont Arsenophonus was also identified on treatments in presence of Bt and antibiotics. The results obtained here are important since little knowledge exists about the gut microbiota on this pest and its interaction with Bt endotoxins. Previous studies made in Lepidoptera suggest that alteration of gut microbiota can be used to improve the management of pest populations, demonstrating the relevance of the results obtained in this work.

Isolation and Identification of Entomopathogenic Fungi from Soils of Manipur (N-E India)

Background: Entomopathogenic fungi (EPF) are natural adversaries of insects, serving a crucial role in the regulation of insect pest populations. In response to the growing demand for sustainable agricultural practices that prioritize environmental protection, human safety and animal welfare, the utilization of bio-control agents like entomopathogenic fungi offers a superior and safe alternative to chemical pesticides. Entomopathogenic fungi effectively infect and eliminate insects, thereby contributing to the control of insect populations through the induction of lethal infections known as epizootics. Isolating EPF from the soil is an effective method as they naturally inhabit soil ecosystems. The north-eastern region of India possesses a forest cover exceeding 80%, with Manipur alone accounting for nearly 75% of forest cover in its total geographical area. This abundant forest cover, along with undisturbed land, contributes to the region’s wealth of micro flora and fauna, including a thriving population of entomopathogenic fungi. However, the potential of these fungi in pest population management remains largely unexplored. Therefore, this study was conducted to investigate the diversity of these promising entomopathogenic fungi. Methods: In this study, we isolated fungi from the soils of ten districts of Manipur and identified several isolates with entomopathogenic properties. Soil bating using Galleria mellonella larvae was employed for the isolation of entomopathogenic fungi. Result: A total of 73 fungal isolates were obtained from 100 soil samples, out of which 54 were identified as entomopathogenic fungi. The genus Aspergillus constituted the most commonly isolated entomopathogenic fungi, followed by isolates of Beauveria, Clonostachys, Talaromyces, Trichoderma, Fusarium, Aspergillus, Candida and Meyerozyma genera. Diversity studies revealed variations in the types and proportions of fungi among different regions of Manipur. Pathogenicity tests confirmed the virulence of the isolated entomopathogenic fungi, with 14 isolates of Beauveria bassiana and two isolates of Talaromyces purpureogenus causing 100% mortality of the test insects. The isolated fungi exhibited excellent performance in insect control and could be further mass-produced for effective pest management.

Impact of metal salts on the survival, development, and oviposition behavior of coconut rhinoceros beetle (Coleoptera: Scarabaeidae).

Oryctes rhinoceros (Coleoptera: Scarabaeidae) is an invasive pest of palms in the Pacific Region, including Hawaii, for which limited management options are available. O. rhinoceros larvae develop in materials rich in organic materials such as green waste and animal manure. Biosolid waste within Hawaii's infestation zone, however, was determined to inhospitable to O. rhinoceros. To determine if the elevated metal salts present in the biosolid waste was responsible for this observation, O. rhinoceros life stages were acutely and chronically exposed to several metal salts at increasing concentrations to determine the impact of these salts on survival, development, and oviposition behavior. Acute (7 days) exposure to mulch rehydrated in solutions of CaCl2, KCl, MgCl2, or NaCl increasing in concentration from 0 to 0.7 M resulted in increased mortality, with concentrations > 0.5 M generally being 100% lethal to both first and second-instar larvae. A similar trend in survival was observed in subsequent experiments using a horticultural grade of Epsom salt (MgSO4) at 1×, 2×, and 5× the recommended application rate. Chronic exposure (eggs reared on mulch through pupation) to Epsom salt at these same rates resulted in significantly delayed instar development and reduced adult biometrics at both 1× and 2× levels. Similar to the acute exposure, eggs exposed to 5× levels did not hatch, or the first instar died soon after emergence. In choice experiments, gravid females showed no oviposition preference for media hydrated with water or 2× Epsom salt but did avoid ovipositing in mulch rehydrated in 5× Epsom salt. These trials demonstrate a potentially novel approach to managing pest populations of O. rhinoceros.

Codling moth (Cydia Pomonella) control using sex pheromones and environmentally friendly insecticides

The research relevance on Codling moth peculiarities is predefined by it being a main threat to apple culture. The sensitivity of apple cultivars that have been planted so far and continue to be planted to this pest diverges in different cultivars. The research aims to determine the main elements of Cydia Pomonella control using sex pheromones and environmentally friendly insecticides. To achieve the goal, an experiment was conducted in the village of Dvoran in the Korcha region on three apple cultivars: Golden Delicious, Star King, and Granny Smith. On the trees of these varieties, traps with sex pheromones were used and environmentally friendly insecticides were utilised. The study found that using sex pheromone traps to monitor Cydia Pomonella is simple and less expensive for apple growers. The Spinosad medicine is the most effective in terms of protection against the pest, the second being Indoxacarb. Golden Delicious and Granny Smith cultivars had the lowest level of pest infestation, while the Star King cultivar was the most affected by Cydia Pomonella. It has also been established that apple fruits do not contain toxic residues, and the ecosystem remains clean. Additionally, the use of sex pheromones can be part of an integrated pest management approach that combines different control methods to sustainably manage pest populations in gardens. The practical significance of the obtained results is that they provide apple growers with a safe and effective method of controlling Cydia pomonella populations in their orchards. In addition, the scientific basis for the use of sex pheromones as a method of pest control can contribute to the implementation of sustainable control methods in apple production

POTENSI PENGENDALIAN HAYATI HAMA SPODOPTERA FRUGIPERDA UNTUK KEBERLANJUTAN PRODUKSI JAGUNG

The armyworm Spodoptera frugiperda, which damages corn plants, is one of the invasive pests. The armyworm S. frugiperda damages corn plants by eating leaf tissue from one side so that the remaining epidermal tissue then makes holes in the leaves and eats from the edge of the leaf to the inside, which causes perforation in the leaves. Control efforts using insecticides have not been practical due to the feeding behaviour of the second and third instar larvae that settle on the inside of the leaves under protected conditions. Therefore, it is necessary to carry out other control techniques that can suppress the development of environmentally friendly S. frugiperda by considering economic and ecological aspects, namely biological control.
 Biological control optimizes the role of natural enemies as biological control agents in efforts to manage pest populations which are part of the chain in agroecosystems. Utilization of natural enemies, parasitoids, predators, and pathogen, can suppress the development of the S. frugiperda pest in corn, reducing the use of synthetic pesticides. Natural enemies of S. frugiperda include the egg parasitoid Telenomus sp. and Trichogramma sp.; larva parasitoid Glyptapanteles creatonoti (Viereck), solitary larval parasitoid Campoletis chlorideae Uchida, and parasitoid larvae of the order Hymenoptera: Ichneumonidae: Ichneumoninae and G. creatonoti. as well as an entomopathogenic species, Nomuraea rileyi (Farl.) Samson. Natural enemies can control S. frugiperda pests to save sustainable maize yields based on the basic principles of sustainable agriculture models. Agroecological steps are taken to reduce the population of S. frugiperda in corn plants by:/ (1) sustainable management of soil fertility, primarily actions that maintain or store soil organic carbon; (2) intercropping with properly selected companion plants; and (3) diversification of the agricultural environment through the management of (semi) natural habitats at various spatial scales.

The Sentinel Bait Station: an automated, intelligent design pest animal baiting system

Context Ground baiting is a strategic method for reducing vertebrate pest populations. Best practice involves maximising bait availability to the target species, although sustaining this availability is resource intensive because baits need to be replaced each time they are taken. This study focused on improving pest population management through the novel baiting technique outlined in this manuscript, although there is potential use across other species and applications (e.g. disease management). Aims To develop and test an automated, intelligent, and semi-permanent, multi-bait dispenser that detects target species before distributing baits and provides another bait when a target species revisits the site. Methods We designed and field tested the Sentinel Bait Station, which comprises a camera trap with in-built species-recognition capacity, wireless communication and a dispenser with the capacity for five baits. A proof-of-concept prototype was developed and validated via laboratory simulation with images collected by the camera. The prototype was then evaluated in the field under real-world conditions with wild-living canids, using non-toxic baits. Key results Field testing achieved 19 automatically offered baits with seven bait removals by canids. The underlying image recognition algorithm yielded an accuracy of 90%, precision of 83%, sensitivity of 68% and a specificity of 96% throughout field testing. The response time of the system, from the point of motion detection (within 6–10 m and the field-of-view of the camera) to a bait being offered to a target species, was 9.81 ± 2.63 s. Conclusion The Sentinel Bait Station was able to distinguish target species from non-target species. Consequently, baits were successfully deployed to target species and withheld from non-target species. Therefore, this proof-of-concept device is able to successfully provide baits to successive targets from secure on-board storage, thereby overcoming the need for daily bait replacement. Implications The proof-of-concept Sentinel Bait Station design, together with the findings and observations from field trials, confirmed the system can deliver multiple baits and increase the specificity in which baits are presented to the target species using artificial intelligence. With further refinement and operational field trials, this device will provide another tool for practitioners to utilise in pest management programs.

A Comparison of RNA Interference via Injection and Feeding in Honey Bees.

Simple SummaryRNA interference is an important way to analyze gene function. It is also widely used in honey bees. It was thought that RNA interference with honey bee brain genes could only be achieved by injection. However, this method of injection is very complicated and can easily cause damage to bees. Recent studies have shown that specially treated siRNA can knockdown brain genes in animals by feeding them. Therefore, we used different approaches to deliver modified and unmodified siRNAs to investigate what methods can successfully interfere with honey bee brain genes. The results of this study are helpful to improve the application of RNA interference techniques in honey bees and other insects.RNA interference (RNAi) has been used successfully to reduce target gene expression and induce specific phenotypes in several species. It has proved useful as a tool to investigate gene function and has the potential to manage pest populations and reduce disease pathogens. However, it is not known whether different administration methods are equally effective at interfering with genes in bees. Therefore, we compared the effects of feeding and injection of small interfering RNA (siRNA) on the messenger RNA (mRNA) levels of alpha-aminoadipic semialdehyde dehydrogenase (ALDH7A1), 4-coumarate-CoA ligase (4CL), and heat shock protein 70 (HSP70). Both feeding and injection of siRNA successfully knocked down the gene but feeding required more siRNA than the injection. Our results suggest that both feeding and injection of siRNA effectively interfere with brain genes in bees. The appropriateness of each method would depend on the situation.

Museum Genomics of an Agricultural Super-Pest, the Colorado Potato Beetle, Leptinotarsa decemlineata (Chrysomelidae), Provides Evidence of Adaptation from Standing Variation.

Despite extensive research on agricultural pests, our knowledge about their evolutionary history is often limited. A mechanistic understanding of the demographic changes and modes of adaptation remains an important goal, as it improves our understanding of organismal responses to environmental change and our ability to sustainably manage pest populations. Emerging genomic datasets now allow for characterization of demographic and adaptive processes, but face limits when they are drawn from contemporary samples, especially in the context of strong demographic change, repeated selection, or adaptation involving modest shifts in allele frequency at many loci. Temporal sampling, however, can improve our ability to reconstruct evolutionary events. Here, we leverage museum samples to examine whether population genomic diversity and structure has changed over time, and to identify genomic regions that appear to be under selection. We focus on the Colorado potato beetle (CPB), Leptinotarsa decemlineata (Say 1824; Coleoptera: Chrysomelidae), which is widely regarded as a super-pest due to its rapid, and repeated, evolution to insecticides. By combining whole genome resequencing data from 78 museum samples with modern sampling, we demonstrate that CPB expanded rapidly in the 19th century, leading to a reduction in diversity and limited genetic structure from the Midwest to Northeast United States. Temporal genome scans provide extensive evidence for selection acting in resistant field populations in Wisconsin and New York, including numerous known insecticide resistance genes. We also validate these results by showing that known selective sweeps in modern populations are identified by our genome scan. Perhaps most importantly, temporal analysis indicates selection on standing genetic variation, as we find evidence for parallel evolution in the two geographical regions. Parallel evolution involves a range of phenotypic traits not previously identified as under selection in CPB, such as reproductive and morphological functional pathways that might be important for adaptation to agricultural habitats.

Carlina acaulis essential oil nanoemulsion as a new grain protectant against different developmental stages of three stored-product beetles.

Plant essential oils (EOs) represent eco-friendly alternatives to conventional insecticides for managing pest populations. Carlina acaulis root EO showed a wide insecticidal spectrum, being highly effective against insect pests and vectors, coupled with low mammal toxicity. To boost the chemico-physical properties of this EO and its main active ingredient, carlina oxide, C. acaulis EO was encapsulated in a nanoemulsion [NE, 6% EO (w/w)], and its insecticidal properties evaluated against larvae and adults of Tribolium castaneum, Tribolium confusum and Tenebrio molitor. Two NE concentrations (500 and 1000 ppm) were applied on stored wheat. Mortality was determined after 4, 8 and 16 h and 1, 2, 3, 4, 5, 6 and 7 days. The NE was toxic to larvae of T. castaneum and T. confusum, killing 93.9% and 98.9% at 1000 ppm after 7 days of exposure, respectively. Tenebrio molitor larvae were tolerant: only 18.9% were dead after 7 days of exposure on stored wheat treated with 1000 ppm NE. However, the NE exhibited high adulticidal activity leading to 85.2% mortality at 1000 ppm, 7 days post-exposure. The mortalities of T. confusum and T. castaneum adults were low (21.4% and 23.3% respectively) at 1000 ppm, 7 days post-exposure. A NE based on C. acaulis EO could be regarded as an efficacious green adulticide or larvicide, depending on the target insect species and its life stage, advancing and specifying the pest management strategies of the tested species in an eco-friendly way. © 2022 Society of Chemical Industry.

ИНСТРУМЕНТАЛЬНЫЙ ЭКОНОМИЧЕСКИЙ УРОВЕНЬ ПОВРЕЖДЕННОСТИ И ЭКОНОМИЧЕСКИЙ ПОРОГ ВРЕДОНОСНОСТИ ПОПУЛЯЦИЙ ПАУТИННОГО КЛЕЩА НА ЗЕМЛЯНИКЕ

Spider mites of the genus Tetranychus are universally one of the significant pests that damage garden strawberries and many other crops. One of the important problems of the pest population management is to be able to identify the thresholds of this pest, which, when feeding, causes a change in the color of plant leaves. Since it is very difficult to determine visually the level of leaf damage by spider mites, the authors of the study turned to the previously substantiated instrumental method for assessing damage using the relative electron transport rate (rETR) based on chlorophyll fluorescence detection in the leaf. Instrumental thresholds of pest damage were calculated: the economic injury level (EIL) and the economic threshold (ET). Studies were carried out in the laboratory on the leaves of strawberry grown in conteiners at temperature of 22 ± 2°C, relative humidity of 75 ± 10%, photoperiod (L : D) 16:8 h, as well as on the experimental plot of the strawberry plantation of JSC “Lenin Sovkhoz” (Moscow region); registration of the population dynamics of spider mites on the leaves being made. At the same time, using the JUNIOR-PAM fluorimeter (Heinz Walz, Germany), the dynamics of chlorophyll fluorescence in the leaves of the control (without mites) and experimental (damaged by mites) variants were measured. As a result, two varieties of industrial strawberries obtained a range of variation of the numerical physiological index, expressed in terms of the ratio of rETRmax between the experimental and control variants, equal to 1.4–2.0 conventional units, which corresponded to the economic injury level (EIL) of strawberry leaves. The latter trait was comparable to the same parameter obtained in the laboratory – 1.6. The economic threshold (ET), which signals the beginning of pesticide treatments, if it is reasonably expected that the number of pests will reach or exceed the value of EIL, also expressed in terms of the ratio of rETRmax between the experimental and control variants, turned out to be equal to 1.1–1.2 conventional units. The authors recommend using the proposed instrumental criteria for the harmfulness of the Atlantic spider mite on strawberries. We believe that this approach can be applied to other species of spider mites, as well as sucking insects.