Control Of Insect Pests Research Articles

Investigating the Potency of Camphor Combined With Kerosene on the Emergence of Anopheles Gambiae

Background Camphor has a long-term application history in the control of insect pests and their mixture with kerosene is not an exception in the control of mosquitoes. Objectives Due to differences in larval biology and positioning in breeding sites, this study was designed to reassess the potency of camphor mixed with kerosene against the emergence of Anopheles mosquitoes in order to ascertain that efficacy of a treatment may not differ greatly with different mosquito species. Methodology Larvae and pupae of Anopheles mosquitoes were collected from Ndokwa West Area of Delta State, Nigeria using standard World Health Organization method and left to acclimatize for 6 h in the Insectary before exposure. Mosquitoes were confirmed as Anopheles gambiae. Camphor (2 g) and its mixture with kerosene in equal ratio were introduced into 100, 200, and 400 mL of water which equated 0.02%, 0.01%, and 0.005%, respectively. Anopheles mosquitoes exposed to only water served as control for the experiment. Twenty larvae and pupae in their third stage of larval development was first sorted into 1000 mL glass beaker and then introduced into various treatment concentrations in 3 replicates. Results Highest mortality was recorded in larvae exposed to 0.02% of camphor mixed with kerosene. Pupae exposed to same concentration compared favorably. Lethal dosage (LD50 and LD95) of camphor exposed to Anopheles larvae and pupae ranged from 0.002% to 0.004% and 0.021% to 0.491%, respectively. More so, values were 0.002% and range from 0.010% to 0.021% in camphor mixed with kerosene, respectively. Conclusion Therefore, the intensification in the use of camphor mixed with kerosene among the population in mosquito breeding sites would reduce the mosquito biting activities and diseases in the locality.

Advancing RNAi-based Strategies for Eco-friendly and Targeted Insect Pest Management in Sustainable Agriculture

The RNA interference (RNAi) has emerged as a promising approach for targeted and eco-friendly insect pest management in sustainable agriculture. The RNAi involves the silencing of specific genes through the introduction of double-stranded RNA (dsRNA), leading to the degradation of complementary mRNA and subsequent reduction in the expression of targeted proteins. This chapter provides a comprehensive overview of the current state and future prospects of RNAi-based strategies for insect pest control. We discuss the molecular mechanisms underlying RNAi, delivery methods for dsRNA, and the design and selection of effective target genes. The application of RNAi in controlling various insect pests, including lepidopterans, coleopterans, and hemipterans is extensively reviewed. also highlight the potential challenges and limitations associated with RNAi-based pest management, such as off-target effects, variable efficacy across insect species, and the development of resistance. Strategies to overcome these challenges, including the use of nanoparticle-based delivery systems and the combination of RNAi with other pest control methods, are explored. Furthermore, discuss the environmental and ecological considerations surrounding the use of RNAi in agriculture, emphasizing the importance of assessing non-target effects and the need for appropriate risk assessment frameworks. The chapter concludes by outlining future research directions and the potential for RNAi to revolutionize insect pest management, contributing to the development of sustainable and resilient agricultural systems.

Role of CYP9E2 and a long non-coding RNA gene in resistance to a spinosad insecticide in the Colorado potato beetle, Leptinotarsa decemlineata.

Spinosads are insecticides used to control insect pests, especially in organic farming where limited tools for pest management exist. However, resistance has developed to spinosads in economically important pests, including Colorado potato beetle (CPB), Leptinotarsa decemlineata. In this study, we used bioassays to determine spinosad sensitivity of two field populations of CPB, one from an organic farm exposed exclusively to spinosad and one from a conventional farm exposed to a variety of insecticides, and a reference insecticide naïve population. We found the field populations exhibited significant levels of resistance compared with the sensitive population. Then, we compared transcriptome profiles between the two field populations to identify genes associated primarily with spinosad resistance and found a cytochrome P450, CYP9E2, and a long non-coding RNA gene, lncRNA-2, were upregulated in the exclusively spinosad-exposed population. Knock-down of these two genes simultaneously in beetles of the spinosad-exposed population using RNA interference (RNAi) resulted in a significant increase in mortality when gene knock-down was followed by spinosad exposure, whereas single knock-downs of each gene produced smaller effects. In addition, knock-down of the lncRNA-2 gene individually resulted in significant reduction in CYP9E2 transcripts. Finally, in silico analysis using an RNA-RNA interaction tool revealed that CYP9E2 mRNA contains multiple binding sites for the lncRNA-2 transcript. Our results imply that CYP9E2 and lncRNA-2 jointly contribute to spinosad resistance in CPB, and lncRNA-2 is involved in regulation of CYP9E2 expression. These results provide evidence that metabolic resistance, driven by overexpression of CYP and lncRNA genes, contributes to spinosad resistance in CPB.

Chemical Composition and Mosquitocidal activity of the methanolic leaf extracts from Ziziphus mauritiana L. against Aedes aegypti L. and Culex quinquefasciatus Say.

Mosquito vectors are a significant cause of pathogen transmission to both animals and humans. Mosquitoes are responsible for transmitting various diseases, including chikungunya, filariasis, West Nile fever, dengue, malaria, and Zika fever, placing approximately 80% of the world's population at risk of infection at any given time. Controlling mosquitoes has become a multifaceted challenge, influenced by diverse environmental factors such as deforestation, urbanization, and climate change on a global scale. For centuries, medicinal plants have been utilized as bioinsecticides to control insect pests. Ziziphus mauritiana, also known as Chinese apple or Indian jujube is a deciduous thorny tree or shrub. Different parts of the Z. mauritiana plant have been traditionally used to treat various common diseases, a practice still prevalent in India and China. In the current investigation, the chemical properties of the Z. mauritiana leaf extract were examined through UV-Vis Spectroscopy, Fourier Transform Infra-Red Spectroscopy (FTIR), and GC-MS Analysis. Second and fourth instar larvae, as well as pupae, of Aedes aegypti and Culex quinquefasciatus were subjected to different concentrations of the methanolic extract of Z. mauritiana for 24 h and 48 h to assess larvicidal and pupicidal activity. The FT-IR spectrum analysis revealed the presence of various functional groups in the chemical compounds extracted from Z. mauritiana, including amines, aromatics, alkanes, alkyls, carbonyls, and carboxylic acids. Additionally, GC-MS analysis identified Isoborneol (25.37%), 4-Acetylbutyric Acid (26.82%), and 2-Vinyl-9-[Beta-D-Ribofuranosyl] Hypoxanthine (24.24%) as the three major phytoconstitutents in the methanol extracts of Z. mauritiana. Regarding the larvicidal activity, the methanolic extract of Z. mauritiana exhibited LC50 values of 155.67 mg/L and 208.57 mg/L for second instar larvae, and 177.68 mg/L and 252.13 mg/L for fourth instar larvae of Cx. quinquefasciatus and Ae. aegypti, respectively, after 24 h of exposure. For pupicidal activity, the LC50 values were 502.02 mg/L and 514.99 mg/L on pupae of Cx. quinquefasciatus and Ae. aegypti, respectively, within 24 h. Overall, the GC-MS analysis provides valuable insights into the chemical composition of the Z. mauritiana extract, highlighting its potential as a natural and eco-friendly alternative for combating insect vectors and contributing to integrated mosquito management programs.

A faster killing effect of plastid-mediated RNA interference on a leaf beetle through induced dysbiosis of the gut bacteria

The expression of double-stranded RNAs (dsRNAs) from the plastid genome has been proven to be an effective method for controlling herbivorous pests by targeting essential insect genes. However, there are limitations to the efficiency of plastid-mediated RNA interference (PM–RNAi) due to the initial damage caused by the insects and their slow response to RNA interference. In this study, we developed transplastomic poplar plants that express dsRNAs targeting the β-Actin (dsACT) and Srp54k (dsSRP54K) genes of Plagiodera versicolora. Feeding experiments showed that transplastomic poplar plants can cause significantly higher mortality in P. versicolora larvae compared with nuclear transgenic or wild-type poplar plants. The efficient killing effect of PM–RNAi on P. versicolora larvae was found to be dependent on the presence of gut bacteria. Importantly, foliar application of a gut bacterial strain, Pseudomonas putida, will induce dysbiosis in the gut bacteria of P. versicolora larvae, leading to a significant acceleration in the speed of killing by PM–RNAi. Overall, our findings suggest that interfering with gut bacteria could be a promising strategy to enhance the effectiveness of PM–RNAi for insect pest control, offering a novel and effective approach for crop protection based on RNAi technology.

Improved YOLOv8 and SAHI Model for the Collaborative Detection of Small Targets at the Micro Scale: A Case Study of Pest Detection in Tea

Pest target identification in agricultural production environments is challenging due to the dense distribution, small size, and high density of pests. Additionally, changeable environmental lighting and complex backgrounds further complicate the detection process. This study focuses on enhancing the recognition performance of tea pests by introducing a lightweight pest image recognition model based on the improved YOLOv8 architecture. First, slicing-aided fine-tuning and slicing-aided hyper inference (SAHI) are proposed to partition input images for enhanced model performance on low-resolution images and small-target detection. Then, based on an ELAN, a generalized efficient layer aggregation network (GELAN) is designed to replace the C2f module in the backbone network, enhance its feature extraction ability, and construct a lightweight model. Additionally, the MS structure is integrated into the neck network of YOLOv8 for feature fusion, enhancing the extraction of fine-grained and coarse-grained semantic information. Furthermore, the BiFormer attention mechanism, based on the Transformer architecture, is introduced to amplify target characteristics of tea pests. Finally, the inner-MPDIoU, based on auxiliary borders, is utilized as a replacement for the original loss function to enhance its learning capacity for complex pest samples. Our experimental results demonstrate that the enhanced YOLOv8 model achieves a precision of 96.32% and a recall of 97.95%, surpassing those of the original YOLOv8 model. Moreover, it attains an mAP@50 score of 98.17%. Compared to Faster R-CNN, SSD, YOLOv5, YOLOv7, and YOLOv8, its average accuracy is 17.04, 11.23, 5.78, 3.75, and 2.71 percentage points higher, respectively. The overall performance of YOLOv8 outperforms that of current mainstream detection models, with a detection speed of 95 FPS. This model effectively balances lightweight design with high accuracy and speed in detecting small targets such as tea pests. It can serve as a valuable reference for the identification and classification of various insect pests in tea gardens within complex production environments, effectively addressing practical application needs and offering guidance for the future monitoring and scientific control of tea insect pests.

Tripartite interactions of an endophytic entomopathogenic fungus, Asian corn borer, and host maize under elevated carbon dioxide.

Biological control of insect pests is encountering an unprecedented challenge in agricultural systems due to the ongoing rise in carbon dioxide (CO2) level. The use of entomopathogenic fungi (EPF) in these systems is gaining increased attention, and EPF as crop endophytes hold the potential for combining insect pest control and yield enhancement of crops, but the effects of increased CO2 concentration on this interaction are poorly understood. Here, the introduction of endophytic EPF was explored as an alternative sustainable management strategy benefiting crops under elevated CO2, using maize (Zea mays), Asian corn borer (Ostrinia furnacalis), and EPF (Beauveria bassiana) to test changes in damage to maize plants from O. furnacalis, and the nutritional status (content of carbon, nitrogen, phosphorus, potassium), biomass, and yield of maize. The results showed that endophytic B. bassiana could alleviate the damage caused by O. furnacalis larvae for maize plants under ambient CO2 concentration, and this effect was enhanced under higher CO2 concentration. Inoculation with B. bassiana effectively counteracted the adverse impact of elevated CO2 on maize plants by preserving the nitrogen content at its baseline level (comparable with ambient CO2 conditions without B. bassiana). Both simultaneous effects could explain the improvement of biomass and yield of maize under B. bassiana inoculation and elevated CO2. This finding provides key information about the multifaceted benefits of B. bassiana as a maize endophyte. Our results highlight the promising potential of incorporating EPF as endophytes into integrated pest management strategies, particularly under elevated CO2 concentrations. © 2024 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Pan-Genome Analysis and Secondary Metabolic Pathway Mining of Biocontrol Bacterium Brevibacillus brevis

Brevibacillus brevis is one of the most common biocontrol strains with broad applications in the prevention and control of plant diseases and insect pests. In order to deepen our understanding of B. brevis genomes, describe their characteristics comprehensively, and mine secondary metabolites, we retrieved the genomic sequences of nine B. brevis strains that had been assembled into complete genomes from the NCBI database. These genomic sequences were analyzed using phylogenetic analysis software, pan-genome analysis software, and secondary metabolite mining software. Results revealed that the genome size of B. brevis strains ranged from 6.16 to 6.73 Mb, with GC content ranging from 47.0% to 54.0%. Phylogenetic analysis classified the nine B. brevis strains into three branches. The analyses of ANI and dDDH showed that B. brevis NEB573 had the potential to become a new species of Brevibacillus and needed further research in the future. The pan-genome analysis identified 10032 gene families, including 3257 core gene families, 3112 accessory gene families, and 3663 unique gene families. In addition, 123 secondary metabolite biosynthetic gene clusters of 20 classes were identified in the genomes of nine B. brevis strains. The major types of biosynthetic gene clusters were non-ribosomal peptide synthase (NRPS) and transAT polyketide synthase (transAT-PKS). Furthermore, a large number of untapped secondary metabolites were identified in B. brevis. In summary, this study elucidated the pan-genome characteristics of the biocontrol bacterium B. brevis and identified its secondary metabolites, providing valuable insights for its further development and utilization.

Assessment of Safe Vegetable Cultivation at Jashore in Bangladesh: Evidence from Country Bean, Cucumber and Pointed Gourd Cultivation

The study was designed to assess the present status and methods of safe vegetable production at farm level in selected areas of Jashore during January-May, 2023. For the study ninety sample farmer were selected by stratified sampling from three sub-district of Jashore. Average farm size was 0.79 ha in study area. Farmer doing different agronomic management such as weeding, irrigation, spraying, de-topping, stalking, earthing up etc. Farmer used different methods simultaneously such as insecticide spray, bio-pesticide, sex pheromone, yellow trap, white trap, hand picking etc. for controlling insect pest. About sixty-four percent farmer sprayed synthetic pesticide and rest of them used bio control method such as bio-pesticide (bio-chamak, eco-mac, bio-envir, bio-cin), sex pheromone trap, yellow trap and hand picking for control insect pest in their fields. About fifty-eight percent farmer used bio-fertilizer along with organic fertilizer (manure, vermin compost) and seventy-eight percent farmer used chemical fertilizer for vegetable cultivation. Total production cost of country bean was Tk.3,36,579 ha-1, cucumber was Tk.3,25,915 ha-1 and pointed gourd was Tk.4,40,106 ha-1. Among the cost item labor cost was highest. Average yield of country bean was 30.60 tha-1, cucumber was 30.08 tha-1 and pointed gourd was 41.60 tha-1. Highest benefit cost ratio was cucumber (2.13) followed by pointed gourd (2.07) and country bean (1.50), that means safe vegetable cultivation also profitable. Farmer awareness, havoc attack of pest and insect were the main problem for safe vegetable cultivation. Market facilities, demand, value chain, proper price for organic vegetable, and farmer motivation can promote and enhance safe vegetable cultivation.

Effect of faba bean nectar on longevity and fecundity of Plutella xylostella and its parasitoid Cotesia vestalis

Intercropping faba bean with vegetables provides a possibility to promote pest control and better nutrient cycling in sustainable agriculture. Faba bean produces extrafloral nectar which supports parasitoid wasps that play a role in the biological control of pest insects. However, adult lepidopteran pests also benefit from nectar, increasing their lifespan and the number of offspring they produce. Here, a laboratory-based study was conducted to assess the role of faba bean on the components of a Brassica-based host-parasitoid system. We measured how access to faba bean affected the longevity and fecundity of the brassica pest Plutella xylostella and its parasitoid Cotesia vestalis. It was also studied if odors of flowering faba bean disrupt host finding by C. vestalis in Y-tube bioassays and volatile organic compounds were analyzed to explain the olfaction-based choices made by the parasitoids. The longevity of C. vestalis was 6.6 times longer and the number of pupae produced almost 10 times greater when they had access to faba bean. Meanwhile, the longevity of P. xylostella was 3.6 times longer and it laid 4.6 times more eggs when provided access to faba bean. In Y-tube bioassays, C. vestalis females also oriented toward host-related odors of the damaged cabbage more than intact cabbage when odors of faba bean were mixed with both of them. In conclusion, faba bean provided sustenance to both pest insects and their natural enemies that prolonged their lifespans and their reproductive capacity.

Evaluation of the performance of maize storage facilities for control of storage insect pests in Ethiopia

Maize plays a vital role in Ethiopia's food security, supporting the lives of millions of people. However, postharvest grain deterioration due to insect infestation is a significant issue. To address this and improve food availability, reducing storage losses is essential. The experiments were carried out in both indoor and outdoor settings, where the indoor experiment evaluated the effectiveness of different storage facilities (jute sack, PICS bag, fertilizer bag, AgroZ® bag, and polypropylene bag) over varying durations (0, 2, 4, 6, and 8 months) in three replications. In the outdoor experiment, traditional and modified gombisa constructed in an open field at the Jimma University Research Site (Eladale), along with different storage duration (initial loading, 2, 4, 6, and 8 months after storage), were evaluated in three replications. The data collected included grain damage percentage, weight loss, seed germination, and proximate analysis. Statistical analysis revealed significant differences in grain damage, weight loss, and seed germination of grains stored in different storage types. Jute sacks showed the most severe damage to grains and weight loss, while PICS and AgroZ® bags had the lowest values. The PICS and AgroZ® bags exhibited the highest seed germination, while the Jute bags had the lowest. In particular, traditional gombisa storage resulted in more significant grain damage, weight loss, and reduced germination than modified gombisa. As storage duration increased, grain damage and weight loss increased significantly in Jute sacks, Polyethylene bags, and traditional gombisa. Furthermore, the proximate analysis showed that storage periods and facilities significantly affected the characteristics of the quality of the maize grain. The moisture content, the crude protein, and the crude fat decreased with longer storage durations in all storage types, while the crude fiber and the ash content increased. The results confirmed the effectiveness of PICS, AgroZ® bags, and modified gombisa in reducing the qualitative and quantitative losses caused by the infestation of storage insect pests. These storage methods can be recommended to protect maize grain for eight months.

The potential neuroprotective of luteolin against acetamiprid-induced neurotoxicity in the rat cerebral cortex.

Acetamiprid is a class of neuroactive insecticides widely used to control insect pests. The current study aimed to investigate the potential neuroprotective effects of luteolin against acetamiprid-induced neurotoxicity in the rat cerebral cortex. Four equal groups of adult male rats (10 in each): control, acetamiprid (40 mg/kg for 28 days), luteolin (50 mg/kg for 28 days), and acetamiprid+luteolin cotreatment were used. Acetamiprid was shown to alter the oxidative state by increasing oxidant levels [nitric oxide (NO) and malondialdehyde (MDA)] and decreasing antioxidants [glutathione (GSH), glutathione peroxidase (GPx), glutathione reductase (GR), superoxide dismutase (SOD), and catalase-(CAT)], with increased activity of nuclear factor erythroid 2-related factor 2-(Nrf2). Likewise, acetamiprid increases the inflammatory response, as evidenced by increased interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α), and nuclear factor kappa B-(NF-κB). In contrast, the treatment with luteolin brought these markers back to levels close to normal, showing that it protects neurocytes from oxidative damage and the neuroinflammation effects of acetamiprid-induced inflammation. Luteolin also demonstrated a neuroprotective role via the modulation of acetylcholinesterase (AChE) activity in the cerebral cortex tissue. Histopathology showed severe neurodegenerative changes, and apoptotic cells were seen in the acetamiprid-induced cerebral cortex layer, which was evident by increased protein expression levels of Bax and caspase-3 and decreased Bcl-2 levels. Histochemistry confirmed the neuronal degeneration, as proven by the change in neurocyte colour from brown to black when stained with a silver stain. Luteolin may have a neuroprotective effect against biochemical and histopathological changes induced by acetamiprid in the rat cerebral cortex.

Chromosome-level genome assembly of the bethylid ectoparasitoid wasp Sclerodermus sp. ‘alternatusi’

The Bethylidae are the most diverse of Hymenoptera chrysidoid families. As external parasitoids, the bethylids have been widely adopted as biocontrol agents to control insect pests worldwide. Thus far, the genomic information of the family Bethylidae has not been reported yet. In this study, we crystallized into a high-quality chromosome-level genome of ant-like bethylid wasps Sclerodermus sp. ‘alternatusi’ (Hymenoptera: Bethylidae) using PacBio sequencing as well as Hi-C technology. The assembled S. alternatusi genome was 162.30 Mb in size with a contig N50 size of 3.83 Mb and scaffold N50 size of 11.10 Mb. Totally, 92.85% assembled sequences anchored to 15 pseudo-chromosomes. A total of 10,204 protein-coding genes were annotated, and 23.01 Mb repetitive sequences occupying 14.17% of genome were pinpointed. The BUSCO results showed that 97.9% of the complete core Insecta genes were identified in the genome, while 97.1% in the gene sets. The high-quality genome of S. alternatusi will not only provide valuable genomic information, but also show insights into parasitoid wasp evolution and bio-control application in future studies.

Establishment of RNAi-Mediated Pest Control Method for Red Imported Fire Ant, Solenopsis invicta.

RNAi plays a crucial role in insect gene function research and pest control field. Nonetheless, the variable efficiency of RNAi across diverse insects and off-target effects also limited its further application. In this study, we cloned six essential housekeeping genes from Solenopsis invicta and conducted RNAi experiments by orally administering dsRNA. Then, we found that mixing with liposomes significantly enhanced the RNAi efficiency by targeting for SiV-ATPaseE. Additionally, we observed a certain lethal effect of this dsRNA on queens by our established RNAi system. Furthermore, no strict sequence-related off-target effects were detected. Finally, the RNAi effect of large-scale bacteria expressing dsRNA was successfully confirmed for controlling S. invicta. In summary, this study established an RNAi system for S. invicta and provided a research template for the future development of nucleic acid drugs based on RNAi.

Insect pests incidence of peanut (Arachis hypogaea L.) in the dryland of Kupang District, East Nusa Tenggara, Indonesia

The presence of insect pests is one of the obstacles in efforts to increase peanut production in Kupang District. This study aimed to evaluate farmers’ knowledge of peanut insect pests and assess their adopted control measures and to identify the types of insect pests and their respective incidence rates in peanut crops. Within each sub-district, two villages were selected on the advice of the local extension agents; five farmers were interviewed using predefined checklists. The checklists were designed to gather information about the farmers’ awareness of various pests affecting their peanut crops and the measures they employed to safeguard their crops. The second part of the study involved examining peanut fields in the chosen locations to assess pest infestation. The results revealed that farmers demonstrated a comprehensive understanding of the insect pests frequently linked to peanut cultivation, but the majority of farmers (64.3%) did not try to control insect pests on their peanut plants. Five insect pests were identified on peanut plants: Aphis craccivora, Anoplocnemis phasiana, Aulacophora indica, Chrysodeixis chalcites, and Lamprosema indicata. The incidences of the identified pests varied between 14.1% to 26.8%. Lamprosema indicata exhibited the lowest incidence, while Aphis craccivora had the highest.

ACCOMPLISHMENTS AND FUTURE OF BIOLOGICAL CONTROL AND INTEGRATED CONTROL IN BRAZIL – PART 1

Efforts to biologically control insect pests in Brazil though modest in the past have in recent years been increasing, and the future possibilities of biological control are most promising if certain facilities and conditions are provided. We shall deal here mainly with biological control. Biological control is a natural ecological phenomenon. It is the regulation of plant and animal numbers by natural enemies. Natural enemies are parasites, predators and pathogens.

Genetic Diversity Analysis of Rhynocoris marginatus Fabricius Based on 18S Ribosomal RNA Gene (Heteroptera: Reduviidae)

The R. marginatus are essential components of ecosystem, but also important in the biological control of insect pest, infesting a varity of agro ecosystem and medicine. The present investigation was carried out in the insect molecular genetic variation of 18S Ribosomal RNA gene from R. marginatus. The study was represent by the reduviid insect R. marginatus nucleotide gene sequences were translate amino acid sequence and obtained hydropathy, Domain, Transmembranes of proteins were calculated. The multiple gene sequence alignment of in-silico translated amino acid sequence of the partial ribosomal genes protein of R. marginatus were generated and the phylogenetic relationships were observed.

Viral diversity in the European spruce bark beetle Ips typographus as revealed through high-throughput sequencing

The European spruce bark beetle, Ips typographus is the economically most important biotic damaging agent of Norway spruce. Efforts to delimit beetle populations by trapping, application of chemical insecticides, or mechanically excluding the beetles from their breeding substrates are often expensive and mostly inadequate. The use of natural enemies and viruses is receiving increased research interest as a potential environmentally healthy approach to control pest insect populations, but practical biocontrol methods against I. typographus are still lacking. To learn more about putative enemies of this pest species, we used high-throughput sequencing to determine its viral community using beetles collected at a Finnish forest site. The analysis revealed a diverse community of RNA viruses associated with I. typographus, including novel viruses that could be affiliated with the classified families Benyviridae, Metaviridae, Narnaviridae, Partitiviridae, Phenuiviridae, Solemoviridae, Virgaviridae, Tombusviridae, and proposed family Spiciviridae, as well as unclassified “quenyaviruses”. Based on phylogenetic analysis, the viruses were distinct from, but resembled, unclassified viruses originating from other arthropods, and many of them were distantly related to previously described viruses. The possibility that the viruses could be hosted by other organisms than the beetle itself (associated fungi, nematodes and protozoa) was addressed by bioinformatic and phylogenetic analyses and is discussed.

The effect of chitin on the effectiveness of Beauveria bassiana formulation product to control cocoa pod borer in vitro

Fungal entomopathogens are suggested to be used as a bioinsecticide due to their biological persistence and ecological friendliness. Beauveria bassiana is an entomopathogenic fungus that can effectively control insect pests, including cocoa pod borer. This study aims to determine the level of effectivity of the B. bassiana (Bb) formulation product from Palu against cocoa pod borer pupae in vitro . This research used a completely randomized design (CRD) consisting of two factors: conidia concentrations and chitin treatments, which were repeated thrice. The conidia concentrations consisted of two levels, that were 106 and 107 conidia/mL. The chitin treatment included seven treatments: isolate from Kediri without formulation with chitin (Bb-K), isolate from Palu without formulation with chitin (Bb-P0), four formulations of isolates from Palu with the addition of chitin to various growth media (Bb-P1, Bb-P2, Bb-P3, and Bb-P4), and control (without Bb suspension). Bb-P0 and Bb-P2 treatments at a concentration of 107conidia/mL began to colonize CPB on the third day after the treatment application, while the other formulations started on the fifth day. However, Bb-P0 showed the lowest infection rate at the end of the observation. Contrarily, the data on the pupa-infected ratio showed that the Bb-P2 treatment was the highest compared to other treatments. It conformed to the adult emergence ratio that Bb-P2 exhibited the lowest, which means Bb-P2 has the most virulence of other formula. The result showed that PDA and PDB media-supplemented chitin was the most effective for culturing B. bassiana origin Palu before mass production.

Key residues involved in the interaction between chlorpyrifos and a chemosensory protein in Rhopalosiphum padi: Implication for tracking chemical residues via insect olfactory proteins

The development of advanced biosensors for tracking chemical residues and detecting environmental pollution is of great significance. Insect chemical sensory proteins, including chemosensory proteins (CSPs), are easy to synthesize and purify and have been used to design proteins for specific biosensor applications. Chlorpyrifos is one of the most commonly used chemicals for controlling insect pests in agriculture. This organophosphate is harmful to aquatic species and has long-term negative consequences for the ecosystem. CSPs can bind and carry a variety of environmental chemicals, including insecticides. However, the mechanism by which CSPs bind to insecticides in aphids has not been clarified. In this study, we discovered that RpCSP1 from Rhopalosiphum padi has a higher affinity for chlorpyrifos, with a Ki value of 4.763 ± 0.491 μM. Multispectral analysis revealed the physicochemical binding mechanism between RpCSP1 and chlorpyrifos. Computational simulation analysis demonstrated that the main factor promoting the development of the RpCSP1-chlorpyrifos complex is polar solvation energy. Four residues (Arg33, Glu94, Gln145, Lys153) were essential in facilitating the interaction between RpCSP1 and chlorpyrifos. Our research has improved knowledge of the relationship between CSPs and organophosphorus pesticides. This knowledge contributes to the advancement of biosensor chips for tracking chemical residues and detecting environmental pollution through the use of CSPs.