Pest Species Research Articles

A genotyping array for the globally invasive vector mosquito, Aedes albopictus

BackgroundAlthough whole-genome sequencing (WGS) is the preferred genotyping method for most genomic analyses, limitations are often experienced when studying genomes characterized by a high percentage of repetitive elements, high linkage, and recombination deserts. The Asian tiger mosquito (Aedes albopictus), for example, has a genome comprising up to 72% repetitive elements, and therefore we set out to develop a single-nucleotide polymorphism (SNP) chip to be more cost-effective. Aedes albopictus is an invasive species originating from Southeast Asia that has recently spread around the world and is a vector for many human diseases. Developing an accessible genotyping platform is essential in advancing biological control methods and understanding the population dynamics of this pest species, with significant implications for public health.MethodsWe designed a SNP chip for Ae. albopictus (Aealbo chip) based on approximately 2.7 million SNPs identified using WGS data from 819 worldwide samples. We validated the chip using laboratory single-pair crosses, comparing technical replicates, and comparing genotypes of samples genotyped by WGS and the SNP chip. We then used the chip for a population genomic analysis of 237 samples from 28 sites in the native range to evaluate its usefulness in describing patterns of genomic variation and tracing the origins of invasions.ResultsProbes on the Aealbo chip targeted 175,396 SNPs in coding and non-coding regions across all three chromosomes, with a density of 102 SNPs per 1 Mb window, and at least one SNP in each of the 17,461 protein-coding genes. Overall, 70% of the probes captured the genetic variation. Segregation analysis found that 98% of the SNPs followed expectations of single-copy Mendelian genes. Comparisons with WGS indicated that sites with genotype disagreements were mostly heterozygotes at loci with WGS read depth < 20, while there was near complete agreement with WGS read depths > 20, indicating that the chip more accurately detects heterozygotes than low-coverage WGS. Sample sizes did not affect the accuracy of the SNP chip genotype calls. Ancestry analyses identified four to five genetic clusters in the native range with various levels of admixture.ConclusionsThe Aealbo chip is highly accurate, is concordant with genotypes from WGS with high sequence coverage, and may be more accurate than low-coverage WGS.Graphical

Beyond the present: How climate change is relevant to pest risk analysis

AbstractClimate change is widely recognized as a critical global challenge with far‐reaching consequences. It affects pest species by altering their population dynamics, actual and potential distribution areas, as well as interactions with their hosts and natural enemies. Climate change thus has potentially important implications for multiple areas of the pest risk analysis (PRA) process. The importance of including climate change in PRA may vary depending on the climatic context of the PRA area in relation to the speed of climate change. If climatic changes within the time horizon of interest are minimal, their potential impact on pest risk is reduced accordingly. For PRAs in a changing climate, we need to be concerned with how future climates could alter our assessment of the risks currently posed by each pest species. While climate can influence the distribution and abundance of pests and hosts alike, its significance will vary depending on the situation. The inclusion of climate change within a PRA also presents challenges. The dynamic nature of climate change, with its complex interactions and uncertainties, can make it difficult to predict and assess the future risks posed by pests accurately. Uncertainties related to future predictions may be much greater than the potential effects associated with climate change and species’ responses to it. This paper outlines examples of the effects of climate change on hosts and different groups of pests, including invertebrates, pathogens, weeds and vector species. The aim is to review the opportunities and challenges of incorporating climate change into PRA, offering insights for a variety of stakeholders including policymakers on this topic.

Rapid risk assessment of plant pathogenic bacteria and protists likely to threaten agriculture, biodiversity and forestry in Zambia

A prioritisation study was conducted to address the lack of adequate information about potential pests likely to be introduced in Zambia and become invasive. The study was conducted by subject matter experts from relevant institutions in and outside Zambia. Although this study focused on major pest categories, this paper only addresses bacteria and Protista. A list of 306 bacterial and 10 Protista species adjudged to affect plants was generated using CABI’s Horizon Scanning Tool. The 316 (total) pest species were refined to focus on pests that affect value chains important to Zambia’s economy. This resulted in a final list of 133 bacteria and eight Protista. Four additional bacteria species considered of phytosanitary interest were added and all 137 bacteria and eight Protista species were subjected to a rapid risk assessment using agreed guidelines. Vectors reported to transmit any of the pathogenic organisms were also subjected to a risk assessment. A proportion of 53% (n = 77 of 145) comprising 73 bacteria and four Protista species were reported as present in Africa. Of these, 42 (57%, n = 73) bacterial species and two (n=4) Protista species were reported in neighbouring countries. Considering a cut-off of 54, the highest scoring pests were 40 bacteria (highest score of 140) and three Protista (highest score of 125). Three actions were suggested for high-scoring pests, a detection surveillance, a pest-initiated pest risk analysis (PRA) or a detection surveillance followed by pest-initiated PRA. A “no action” was suggested where the risk was very low although, for some pathogenic organisms, a “no action” was followed by periodic monitoring. This information will contribute towards proactive prevention and management of biological invasions.

Development of remote-controlled solar-powered pesticide sprayer vehicle

Pest species pose a significant threat to the agricultural industry as they can negatively impact crop productivity and result in potential financial losses due to damage. This research aims to address agricultural challenges in the local area and improve the efficiency of pesticide application. A solar-powered, remote-controlled, semi-automated knapsack sprayer vehicle has been developed to address this issue. It operates using a 100 AH battery that is charged by four 30W solar panels connected in tandem to produce 120 W, providing power to the motors and pump. The vehicle uses a 12 V hub motor to drive the back and steer the front and is equipped with a 12 V window regulator/wiper motor. The vehicle is controlled by a remote control and an HC-05 transmitter and receiver, programmed with an ATMEGA32A linked to a relay board. The vehicle utilizes a 116 psi ≈ 799.8 kPa pump for the sprayer. Results indicate that as the feed pressure increases, the flow rate steadily rises and reaches 4 L per minute at the 799.8 kPa pump. With a pump spray rate of 5 L per minute when increased and a pesticide tank capacity of 20 L, the vehicle can spray for a total of 4 min and cover 159 m. Employing a remote control reduces the need for manual labour, making pesticide spraying more consistent, efficient, and productive. The sprayer also saves time compared to traditional methods and poses no harm to the operator.

Resistance risk assessment, cross-resistance potential and realized heritability of resistance to methomyl in Musca domestica Linnaeus.

The use of insecticides in agricultural settings often exerts negative effects on nontarget species. Methomyl, a broad-spectrum carbamate insecticide, is recommended to manage a number of insect pests of the cotton crop. Recently, Musca domestica, which is a nontarget insect species in cotton fields, has shown resistance to methomyl in Pakistan. The present study tried to assess resistance-risk assessment, rapidity of resistance development to methomyl, cross-resistance potential to other insecticides, resistance heritability and to forecast the projected rate of resistance development under field conditions. For this purpose, a field strain of M. domestica with 186 fold resistance to methomyl was re-selected in the laboratory for eight consecutive generations. Consequently, LD50 values increased rapidly (126.64 ng/fly to 3112.79 ng/fly) compared to those before selection experiments. Similarly, RR values increased from 186 to 3113 fold as a result of the selection process. However, resistance to methomyl did not remain stable when the selected strain (Meth-SEL) reared for the next five generations in a pesticide free environment. The Meth-SEL strain also developed cross-resistance to permethrin. The realized heritability (h2) value for the Meth-SEL strain was 0.39 with 27% average mortality of M. domestica. Assuming the standard deviation (σp) value 0.27 and the h2 value 0.39 for eight generations of continuous exposure to methomyl, then five, seven, eight, ten and twelve generations at 90, 80, 70, 60 and 50% selection intensity, respectively, would be required for a tenfold increase in the LD50 value of methomyl. In conclusion, the Meth-SEL strain of M. domestica exhibited a high risk of resistance development to methomyl under continuous selection pressure. Resistance increased rapidly during selection experiments that reflect the probability of resistance development under field conditions if M. domestica receive exposures to methomyl during its applications for the management of target pest species.

Kayısı Bahçelerinde Kullanılan Bazı Pestisitlerin Laboratuvar Koşullarında Exochomus nigromaculatus (Coleoptera:Coccinellidae)’a Karşı Yan Etkilerinin Araştırılması

Several harmful pest species can cause damage to apricot trees. Chemical control is the often preferred method in controlling these pests. The use of pesticides has generally resulted in pesticide resistance and elimination of natural enemies. Exochomus nigromaculatus is a predatory insect of globose scale and other scale insects. Inappropriate use of pesticides has been linked with adverse effects on non-target organisms (e.g., reduction of beneficial species populations and increase of pest populations). This study evaluated the side effects of five insecticides (Acetamiprid, deltamethrin, spirotetramat, sulfoxaflor, dimethoate) and a plant extract (orange oil) on immature stages of E. nigromaculatus using dry film method. Acetamiprid and deltamethrin caused the highest mortality rate (97.3%) besides standard toxic dimethoate. Sulfoxaflor accounted for approximately 70% mortality to E. nigromaculatus. In contrast, spirotetramat and orange oil caused less than 20% mortality to the predator. As a result of the dry film method applied against the pre-adult stage of E. nigromaculatus; dimethoate was classified as harmful (class 4), acetamiprid and deltamethrin were classified as moderately harmful (class 3), sulfoxaflor were classified as less harmful, (class 2) while spirotetramat and orange oil were classified as harmless. Thus, it was concluded that spirotetramat and orange oil did not have a negative effect on the predatory insect, E. nigromaculatus and could be used safely in IPM programs.

A comparison of adult population fluctuation of Anastrepha pest species between agricultural environments and protected natural areas in northeastern Mexico

AbstractFruit fly pestiferous species within the genus Anastrepha Schiner (Diptera: Tephritidae) affect fruit growing in northeastern Mexico, particularly citrus and mango production. Little is known about the population fluctuation of these pests in protected natural areas adjacent to agricultural environments. This study aimed to compare and analyse the temporal profiles of adult populations of Anastrepha pest species inhabiting agricultural zones and a protected natural area. Six years of adult capture data of Anastrepha ludens (Loew), A. obliqua (Macquart), A. striata Schiner and A. serpentina (Wiedemann) were compared and analysed between commercial orchards and fruit tree areas located in the buffer zone of the biosphere reserve “El Cielo”. The analyses were carried out for each of two triennial periods (2008–2010 and 2019–2021). Temporal patterns of the pest populations were characterized, and generalized linear mixed models were used for data analysis. All locations registered the four species, although Anastrepha ludens and A. obliqua represented the highest number of adult captures. Populations of pest species of Anastrepha showed similar fluctuation patterns throughout the year regardless of the location. However, significant differences in the population size were noted between the “El Cielo” reserve and commercial areas. The “El Cielo” reserve and its surroundings captured the highest population levels of the four species. Persistent populations of A. striata and A. serpentina were related to the area under ecological protection. The “El Cielo” reserve is a shelter for the pest species of Anastrepha, which are mainly linked to backyard hosts. We discuss the importance of these findings in the context of an Area‐Wide Integrated Pest Management approach and of studying fruit flies' quarantine pests in Mexico's neotropical limits. Practical implications in designing specific phytosanitary measures to suppress or control pest populations are addressed.

Aberrant splicing of a nicotinic acetylcholine receptor alpha 6 subunit is associated with spinosad tolerance in the thrips predator Orius laevigatus

Susceptibility to insecticides is one of the limiting factors preventing wider adoption of natural enemies to control insect pest populations. Identification and selective breeding of insecticide tolerant strains of commercially used biological control agents (BCAs) is one of the approaches to overcome this constraint. Although a number of beneficial insects have been selected for increased tolerance to insecticides the molecular mechanisms underpinning these shifts in tolerance are not well characterised. Here we investigated the molecular mechanisms of enhanced tolerance of a lab selected strain of Orius laevigatus (Fieber) to the commonly used biopesticide spinosad. Transcriptomic analysis showed that spinosad tolerance is not a result of overexpressed detoxification genes. Molecular analysis of the target site for spinosyns, the nicotinic acetylcholine receptor (nAChR), revealed increased expression of truncated transcripts of the nAChR α6 subunit in the spinosad selected strain, a mechanism of resistance which was described previously in insect pest species. Collectively, our results demonstrate the mechanisms by which some beneficial biological control agents can evolve insecticide tolerance and will inform the development and deployment of insecticide-tolerant natural enemies in integrated pest management strategies.

GROUNDNUT CROP PEST DETECTION AND CLASSIFICATION USING COMPREHENSIVE DEEP-LEARNING MODELS

Pests pose a significant threat to crops, leading to substantial economic losses and decreased food production. Early detection and accurate classification of pests in crops are crucial for effective pest management strategies. In this study, we propose a method for pest detection and classification in groundnut crops using deep learning models. In this research, we compare the performance of three deep learning models, namely Custom CNN [proposed], LeNet-5, and VGG-16, for groundnut pest detection and classification. A comprehensive dataset containing images of diverse groundnut crop pests, including thrips, aphids, armyworms, and wireworms, from the IP102 dataset was utilized for model evaluation. The performance is evaluated using reliability metrics such as accuracy and loss. These findings demonstrate the utility of deep learning models for reliable pest classification of groundnut crops. The Custom CNN [proposed] model demonstrates high training accuracy but potential overfitting, while the VGG-16 model performs well on both training and test data, showcasing its ability to generalize. The models’ accuracy in predicting pest species underscores their capability to capture and utilize visual patterns for precise classification. These findings underscore the potential of deep learning models, particularly the VGG-16 model, for pest detection and classification in groundnut crops. The knowledge gained from this study can contribute to the development of practical pest management strategies and aid in maintaining crop health and productivity. Further analysis and comparisons with other models are recommended to comprehensively evaluate the competitiveness and suitability of deep learning models in real-world applications of pest detection and classification in agricultural settings.

Optimal allocation of resources among general and species-specific tools for plant pest biosecurity surveillance.

This paper proposes a surveillance model for plant pests that can optimally allocate resources among survey tools with varying properties. While some survey tools are highly specific for the detection of a single pest species, others are more generalized. There is considerable variation in the cost and sensitivity of these tools, but there are no guidelines or frameworks for identifying which tools are most cost-effective when used in surveillance programs that target the detection of newly invaded populations. To address this gap, we applied our model to design a trapping surveillance program in New Zealand for bark- and wood-boring insects, some of the most serious forest pests worldwide. Our findings show that exclusively utilizing generalized traps (GTs) proves to be highly cost-effective across a wide range of scenarios, particularly when they are capable of capturing all pest species. Implementing surveillance programs that only employ specialized traps (ST) is cost-effective only when these traps can detect highly damaging pests. However, even in such cases, they significantly lag in cost-effectiveness compared to GT-only programs due to their restricted coverage. When both GTs and STs are used in an integrated surveillance program, the total expected cost (TEC) generally diminishes when compared to programs relying on a single type of trap. However, this relative reduction in TEC is only marginally larger than that achieved with GT-only programs, as long as highly damaging species can be detected by GTs. The proportion of STs among the optimal required traps fluctuates based on several factors, including the relative pricing of GTs and STs, pest arrival rates, potential damage, and, more prominently, the coverage capacity of GTs. Our analysis suggests that deploying GTs extensively across landscapes appears to be more cost-effective in areas with either very high or very low levels of relative risk density, potential damage, and arrival rate. Finally, STs are less likely to be required when the pests that are detected by those tools have a higher likelihood of successful eradication because delaying detection becomes less costly for these species.

Involvement of miR-8510a-3p in response to Cry1Ac protoxin by regulating PxABCG3 in Plutella xylostella

Overuse of insecticides has accelerated the evolution of insecticide resistance and created serious environmental concerns worldwide, thus incentivizing development of alternative methods. Bacillus thuringiensis (Bt) is an insecticidal bacterium that has been developed as a biopesticide to successfully control multiple species of pests. It operates by secreting several insect toxins such as Cry1Ac. However, metabolic resistance based on ATP-binding cassette (ABC) transporters may play a crucial role in the development of metabolic resistance to Bt. Here, we characterized an ABCG gene from the agricultural pest Plutella xylostella (PxABCG3) and found that it was highly expressed in a Cry1Ac-resistant strain, up-regulated after Cry1Ac protoxin treatment. Binding miR-8510a-3p to the coding sequence (CDS) of PxABCG3 was then confirmed by a luciferase reporter assay and RNA immunoprecipitation. miR-8510a-3p agomir delivery markedly reduced PxABCG3 expression in vivo and consequently decreased the tolerance of P. xylostella to Cry1Ac, while reduction of miR-8510a-3p significantly increased PxABCG3 expression, accompanied by an increased tolerance to Cry1Ac. Our results suggest that miR-8510a-3p could potentially be used as a novel molecular target against P. xylostella or other lepidopterans, providing novel insights into developing effective and environmentally friendly pesticides.

Detection and Identification of Quarantine and Non-Quarantine Pest Species of Prunus avium Agroecosystem in Kyrgyzstan

Research of agroecosystem is a comprehensive study of one species with in biocenosis taking into account integrated plant protection to increase output. Gardeners in developing countries most often resort to the use of highly toxic universal pesticides, which leads to the Pesticide Syndrome with general decline of these products. The purpose of the research is to identify fauna of the cherry orchard in the south of Kyrgyzstan to apply eco-methods to control pest of stone fruits. Research objectives: 1) identification of organisms in the agrocenosis of the cherry orchard; 2) classification into biological groups; 3) comparison of the experimental and control fields. Our work was carried out in the autumn and spring periods on 2 experimental fields in the South of Kyrgyzstan for 2021-2022. The identified fauna species comprised of 26 species, which are: Coleoptera (26.9%) the largest order; followed by Lepidoptera and Equidoptera (Homoptera) (19.2%); and Hymenoptera (15.4%). The others are less than 10%: Diptera (7.7%); Acariformes; Hemiptera; Neuroptera (3.8%). At the same time, Coleoptera (26.9%) and Lepidoptera pests make up the bulk of the biomass of the agrocenosis of cherry orchard (19.2%) which dominants and most harmful. The research field no. 1 with annual pesticide load has 20% quarantine pest species with no zoophages among identified species. Whereas non-pesticide-treated field no. 2, no quarantine species, there is biocontrol and with richer biodiversity where trophic relationships is preserved.

Bio-efficacy and Persistence of Inert Dust Formulations as Stored-grain Protectants against Sitophilus oryzae (L.)

&#x0D; &#x0D; &#x0D; Inert dust formulations of natural origin act as promising alternatives in controlling storage infestations caused by deleterious coleopteran insect pests. In that context, laboratory studies were conducted in order to evaluate the insecticidal activity, progeny inhibition and persistence of three commercially available dust formulations, namely, diatomaceous earth, zeolite and cloisite 20A against Sitophilus oryzae adults, a major coleopteran pest of stored grains, throughout 90 days of storage period. Adulticidal and persistence bioassays were conducted to evaluate the toxicity of binary combinations of inert dusts using their sub-lethal doses towards the test insect for 60 days of storage period. Further, ultrastructural architecture of the test insect pest species was examined via Field Emission Scanning Electron Microscopy (FE-SEM), and Energy Dispersive X-Ray Analysis (EDX) to study the uptake/penetration pattern of inert dust particles through the cuticular layers of target insect pest. All inert dust formulations exhibited very efficacious toxic and progeny inhibition activities and extraordinary mortality percentages irrespective of the inert dust used at the end of initial 30 day-long storage period. Thereafter, mortality percentages gradually declined with the progress of the storage time period, declining in the order of, diatomaceous earth&gt;zeolite&gt;cloisite 20A. All the dust formulations successfully inhibited the progeny production and the lowest average progeny production was recorded at the end of initial storage period. Progeny inhibition decreased with the progress of storage time. Binary combinations of inert dust formulations exhibited additive and antagonistic effects against S. oryzae and similarly, the mortality percentages gradually decreased with the prolongation of the storage period. The FE-SEM and EDX micrographs clearly indicated the presence of dust particles and the distribution of their constituting elements on the cuticular layer of the exposed insect pests with the appearances of abrasions and scratches that may have led to dehydration and eventual death of S. oryzae. Thus, findings of the present study suggest that, naturally-derived diatomaceous earth, zeolite and cloisite 20A can be used as eco-friendly means as stored grain protectants against S. oryzae populations successfully in the storage grain systems.&#x0D; Keywords: Sitophilus oryzae, Diatomaceous earth, Cloisite 20A, Zeolite&#x0D; &#x0D; &#x0D;

Comparison of baiting strategies in common vole management.

Worldwide, pest rodents can cause extensive damage to agriculture, forestry, food storage, and infrastructure and pose a risk to public health and livestock due to the spread of zoonotic pathogens. In Europe, the most common pest rodent species is the common vole (Microtus arvalis). Management during periodic outbreaks largely relies on rodenticidal bait with zinc phosphide. Efficient baiting with rodenticides or possibly anti-fertility products in the future require baiting methods that allow a sufficient proportion of the population to consume an effective dose of bait. We used a bait with the quantitative marker ethyl-iophenoxic acid (Et-IPA) to evaluate baiting strategies in enclosure experiments. This wheat-based bait with Et-IPA was placed in bait boxes or directly into the tunnel system entrances in different seasons and common vole abundances. Voles were live-trapped, individually marked and blood samples were collected to relate Et-IPA blood residues to bait uptake. The percentage of animals consuming bait was not heavily affected by the baiting strategy but voles had higher Et-IPA blood residues if tunnel baiting was used in autumn and if bait boxes were used in winter. Non-reproductive as well as lighter animals tended to have higher Et-IPA blood residues than reproductive individuals, whereas sex had no effect. Population density had a negative effect on the probability of residues present as well as on Et-IPA blood concentration. The results of this study might help to improve baiting techniques to manage overabundant rodent pest species regardless of the compounds to be delivered. © 2024 Julius Kühn-Institut. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

The paper wasps (Hymenoptera: Vespidae: Polistinae) of Sri Lanka recorded from recent investigations.

Paper wasps of subfamily Polistinae Lepeletier have been studied in many countries of the world due to their importance as pest species, predators, model organisms in research and medical significance. Seven species have been well documented in Sri Lanka, of these five species represent genus Ropalidia Gurin-Mneville, and two species genus Polistes Latrielle. However, the species have not been studied systematically for many years and recent records are not available. In the present study investigations for wasps (Vespidae) were conducted in 28 locations of all provinces and climatic zones of the country. Five species of paper wasps were found in 15 of the locations investigated, four in the genus Ropalidia and one in the genus Polistes. Ropalidia marginata Lepeletier was the most abundant and widely distributed species, while the other species had more limited distribution. Polistes (Gyrostoma) olivaceus De Geer, previously recorded from Sri Lanka, was not recorded during the present study. All the species of paper wasps encountered in the present study showed changes in distribution from their historical locations, decline in distributional ranges and occurrence in new locations.

Incorporation of climate change into a multiple stressor risk assessment for the Chinook salmon (Oncorhynchus tshawytscha) population in the Yakima River, Washington, USA.

One outcome of the 2022 Society of Environmental Toxicology and Chemistry Pellston Workshop on incorporating climate change predictions into ecological risk assessments was the key question of how to integrate ecological risk assessments that focus on contaminants with the environmental alterations from climate projections. This article summarizes the results of integrating selected direct and indirect effects of climate change into an existing Bayesian network previously used for ecological risk assessment. The existing Bayesian Network Relative Risk Model integrated the effects of two organophosphate pesticides (malathion and diazinon), water temperature, and dissolved oxygen levels on the Chinook salmon population in the Yakima River Basin (YRB), Washington, USA. The endpoint was defined as the entity, Yakima River metapopulation, and the attribute was defined as no decline to a subpopulation or the overall metapopulation. In this manner, we addressed the management objective of no net loss of Chinook salmon, an iconic and protected species. Climate change-induced changes in water quality parameters (temperature and dissolved oxygen levels) used models based on projected climatic conditions in the 2050s and 2080s by the use of a probabilistic model. Pesticide concentrations in the original model were modified assuming different scenarios of pest control strategies in the future, because climate change may alter pest numbers and species. Our results predict that future direct and indirect changes to the YRB will result in a greater probability that the salmon population will continue to fail to meet the management objective of no net loss. As indicated by the sensitivity analysis, the key driver in salmon population risk was found to be current and future changes in temperature and dissolved oxygen, with pesticide concentrations being not as important. Integr Environ Assess Manag 2024;20:419-432. © 2023 The Authors. Integrated Environmental Assessment and Management published by Wiley Periodicals LLC on behalf of Society of Environmental Toxicology & Chemistry (SETAC).

Variation in RNA interference sensitivity in the southern pine beetle, Dendroctonus frontalis (Coleoptera: Curculionidae)

Abstract Intraspecific genetic variation underpins many evolutionary processes and phenomena. For species considered pests, the dynamics of how genetic variation is distributed geographically take on a greater importance, because they can impact pest-management strategies directly. This is particularly true when management strategies are genetic in nature, such as population manipulation via RNA interference (RNAi; a naturally occurring antiviral response that disrupts translation of messenger RNAs into proteins to silence genes). Using RNAi for gene silencing is highly species specific; however, the efficacy of this approach in geographically distinct populations of widespread pest species has not been evaluated comprehensively. Here, we present a preliminary study evaluating differential susceptibility of geographically disparate populations of southern pine beetle, Dendroctonus frontalis, to RNAi. Although the efficacy of RNAi has been demonstrated in localized populations, D. frontalis has a broad distribution across North and Central America and is expanding its range owing to climate change. We observe differences in response between and within geographically distinct populations from its core range and recently expanded range. Our findings have broad implications for the use of RNAi as a management tool in widely distributed species and highlight the need for a deeper understanding of intraspecific genetic variation in this species and others.

Seasonal abundance and trap comparisons of the invasive brown marmorated stink bug Halyomorpha halys (Hemiptera: Pentatomidae) adults from its native region

A challenging, yet fundamental part of initiating effective control measures against an invasive pest species is developing reliable means of monitoring the pest’s seasonal abundance. Halyomorpha halys, a polyphagous insect pest native to East Asia, has become a major economic threat to agricultural systems following unintentional introductions to North America, South America, and Europe. Research involving the seasonal phenology and monitoring attractant preferences of H. halys from its native range remain scarce. An 11-year collection of H. halys monitoring trap data from black light, incandescent light, and methyl (E, E, Z)-2, 4, 6-decatrienoate (MDT) lured traps from three locations in Kyoto, Japan was analyzed to fill gaps in knowledge relating to the native seasonal abundance and effectiveness of diferent trapping techniques for the pest. Due to a high amount of zero trap counts, a zero-inflated approach was taken to analyze the dataset. Overall, H. halys followed a bell-shaped population trend in Kyoto, with abundance peaking in the mid-summer. The attractant preference of H. halys varied slightly with the season, with black light traps producing to highest mean trap counts. The MDT lure traps generated the lowest mean trap counts, but displayed potential use in the reliable detection of early season H. halys. This work is expected to provide greater insight on H. halys in its native range and ultimately help refine existing management programs in invaded regions.

Host-instar selection, interspecific competition, and reproductive capacity of extant and novel parasitoids (Hymenoptera: Braconidae) on Egyptian cotton leafworm

Abstract Background Cotesia marginiventris (Cresson) and Microplitis rufiventris Kok. (Hymenoptera: Braconidae) are larval endoparasitoids of Spodoptera frugiperda (Smith) and S. littoralis (Boisd.), respectively. Cotesia marginiventris was introduced in Egypt to control the recent invasive pest, S. frugiperda and local one, S. littoralis. Therefore, competition between the two parasitoid species may occur. Results When single females of C. marginiventris (Exp. 1), single females of M. rufiventris (Exp. 2), and one female each of C. marginiventris and M. rufiventris (Exp. 3) were offered a choice of 60 1st, 60 2nd, and 60 3rd instars, of the tested host species, S. littoralis and different parasitization levels were obtained. In the non-competitive context (Exps. 1, 2), all instars were parasitized, but C. marginiventris and M. rufiventris parasitized primarily 2nd and 3rd instar host larvae, respectively. In the competitive context (Exp. 3), the same preference pattern emerged but the percentage of parasitism was lower than in each of the two non-competitive contexts. Conclusions M. rufiventris appears to be a superior competitor when simultaneously exploiting the host with the other parasitoid species. The knowledge of this work can be used to predict and/or understand possible outcomes of a biological control program using the two biocontrol agents against one or the two pests species, and to gain insight into possible biotic interference between species at the same trophic level exploiting the same host. Graphical abstract

ECONOMIC PROBLEMS RELATED TO ECOLOGY AND CLIMATE CHANGE

Global climate change is widely studied globally. Today on Earth global climate change is observed. The average temperature on our planet is over thirty a degree increased in the year. New species of insects and pests have appeared. This a very big problem. Hence the climate change that the study raises causes, among other problems, humanity in nature during its existence is associated with interference. Logging, plowing, land improvement, and etc. will cause changes in humidity and wind conditions and an opinion on this -mulochases can attract the attention of a person and bring the scientific novelty of the topic increases.