Target Arthropods Research Articles

Risk Assessment of the Pesticide Coragen 20 SC with the Active Substance Chlorantraniliprole

Coragen 20 SC is a new product in Norway containing the active substance chlorantraniliprole. It is applied for use in apples against codling moth (Cydia pomonella), apple fruit moth (Argyresthia conjugella) and free leaf living larvae. The Norwegian Scientific Committee for Food Safety (VKM) was asked by the Norwegian Food Safety Authority to perform a risk assessment on human health, environmental fate and ecotoxicological of the active substance and the product. The risk assessment of the product was approved at a meeting 11th of May 2010 by VKMs Scientific Panel on Pesticides (Panel 2). VKMs Panel 2 concludes as following: The product and the active substance have low acute oral, dermal and inhalation toxicities. Both are non-irritating to the skin, and no allergenic potential by skin contact were shown. Coragen was non-irritating to the eyes, while chlorantraniliprole showed a weak irritating potential. Chlorantraniliprole is not shown to have any genotoxic or carcinogenic potential, or to be teratogenic or toxic to the reproduction of female animals. The potential for testicular toxicity of chlorantraniliprole is unclear because the study design and the limited number of young dogs (2/sex/group) do not provide basis for a firm conclusion. No particular target organ for toxicity in any species in the sub-chronic and chronic toxicity studies was seen. The observed dose- and time dependent increased degree of microvesiculation in the zona fasiculata of the adrenal cortex in male rats, is however of uncertain biological significance. All test species (rat, mice, dog) showed physiological adaption to chlorantraniliprole administration (increased liver metabolism with induction of cytochrome P450 enzymes) which was manifested as increased liver weight and hepatocellular hypertrophy. In the chronic toxicity study in mice, the increased liver weight and hepatocellular hypertophy was accompanied with eosinofilic foci, which was assessed as an adverse effect. The no observed effect level (NOAEL) derived from this study serves as basis for calculations of values for acceptable daily intake (ADI) and acceptable operator exposure level (AOEL). 
 In Panel 2‘s opinion a sub-chronic study (90 days) with the technical material (E2Y45-282) including relevant concentration of the impurity IN-G2S78 should be performed. This would bring information on possible influence of the impurity on the toxicological profile of the technical material, and consequently on the assessment of the NOAELs in the various toxic studies. 
 The estimated risk for operator and for bystanders or for workers re-entering treated crops is assessed as minimal. 
 Chlorantraniliprole is persistent in soil with half live of about 1 year. The long half life indicates high potential for accumulation in soil after repeated use, which is confirmed by both model simulations and field studies. The Panel considers field data from the south of Europe not to be relevant for the Nordic conditions based on different climate conditions and soil properties contributing in different directions.
 The Panel considers that the existing documentation is not sufficient for a firm conclusion on the use of normalised field data for modelling purposes. However, the substance is persistent and expected to accumulate in soil. The Panel concludes that there is minimal risk for toxic effects on mammals, birds, bees, and microorganisms in soil due to chlorantraniliprole exposure with the proposed exposure regime. Panel concludes that there is “very high risk” for effects on in-field non target arthropods from chlorantraniliprole exposure. 
 For soil living invertebrates, earthworms seem rather insensitive to chlorantraniliprole and the Panel considers the toxic effects to be minimal. Panel considers the risk for toxic effects on soil living arthropods to be high. Crustaceans and insects larvae are the aquatic organisms most sensitive to chlorantraniliprole. The Panel concludes that there is a minimal risk of toxic effects on aquatic organisms due to exposure to chlorantraniliprole with the proposed application regime provided that a buffer zone of 30 m to surface water is applied.

Improving Natural Enemy Selection in Biological Control through Greater Attention to Chemical Ecology and Host-Associated Differentiation of Target Arthropod Pests.

Simple SummarySome species of insect herbivores can feed on a wide variety of plant species. Over evolutionary time, insect herbivores can associate preferentially with different host-plant species, which frequently leads to genetic divergence between populations of an herbivore species. This phenomenon, referred to as host-associated differentiation (HAD), not only affects insect herbivores, but can also impact their associated natural enemies, particularly predatory or parasitic insects, which are responsible for biological control in agroecosystems. Although the mechanisms underlying HAD in populations of herbivores and associated natural enemies remain underexplored, we argue that the chemical communication between plants, herbivores, and natural enemies likely plays a major role. Chemical cues emitted by plants and insect herbivores influence natural enemy foraging behavior, and divergent chemical cues can lead to natural enemy HAD, ultimately shaping biological control. In this synthesis paper, we explore how the chemical ecology of HAD could influence classical, conservation, and augmentative biological control, and propose research agendas to further biological control efficacy through natural enemy selection.Host-associated differentiation (HAD) refers to cases in which genetically distinct populations of a species (e.g., herbivores or natural enemies) preferentially reproduce or feed on different host species. In agroecosystems, HAD often results in unique strains or biotypes of pest species, each attacking different species of crops. However, HAD is not restricted to pest populations, and may cascade to the third trophic level, affecting host selection by natural enemies, and ultimately leading to HAD within natural enemy species. Natural enemy HAD may affect the outcomes of biological control efforts, whether classical, conservation, or augmentative. Here, we explore the potential effects of pest and natural enemy HAD on biological control in agroecosystems, with emphases on current knowledge gaps and implications of HAD for selection of biological control agents. Additionally, given the importance of semiochemicals in mediating interactions between trophic levels, we emphasize the role of chemical ecology in interactions between pests and natural enemies, and suggest areas of consideration for biological control. Overall, we aim to jump-start a conversation concerning the relevance of HAD in biological control by reviewing currently available information on natural enemy HAD, identifying challenges to incorporating HAD considerations into biological control efforts, and proposing future research directions on natural enemy selection and HAD.

Dynamic monitoring of the impact of insect-resistant transgenic poplar field stands on arthropod communities

The safety of genetically modified forest trees is an important ecological issue worldwide, and concerns about genetic modification are one factor hindering in-depth research and large-scale planting of genetically modified trees. This study evaluated the impact of transgenic poplars on the ecosystem by analyzing differences in arthropod communities, target arthropods, and nontarget arthropods in transgenic (BtCryIAc) and non-transgenic experimental forests of Populus × euramericana cv. “74/76” (hereafter, tPE and ntPE, respectively). Five years of dynamic monitoring showed that the tPE had stable and lasting insect resistance to Lepidoptera, especially Arctiidae. However, the insertion of exogenous genes also had a negative impact on certain tPE line. The principle response curves (PRC) indicated that the genetic modification contributed much less to the community difference than the year factor (7% vs. 60%, respectively), and nontarget arthropods may be more sensitive to interannual variations. Nontarget arthropods that respond sharply to the PRC curve include Aphididae and Tenthredinidae (species weight > 0.5), but this difference appears only in certain years or lines. Our research shows that the tPE had no obvious adverse effects on nontarget arthropods. In areas with severe lepidopteran pests, the tPE could help to increase the diversity and stability of arthropod communities, while providing greater ecological and economic benefits than non-transgenic poplars.

Controversial impact of experimental soil inoculant containing Beauveria bassiana and Metarhizium anisopliae on Sitophilus granarius

AbstractThe insecticidal efficacy of the experimental bioinoculants (Natur Nova, Natur Agro Hungary Ltd., Hungary) containingBeauveria bassiana(Bals.-Criv). Vuill. andMetarhizium anisopliaeMetschnikoff against stored product pests modelled by granary weevil,Sitophilus granariusL. was evaluated on wheat in laboratory tests. In order to comparability, two applications were also set up: one purely ash-treated grain treatment against wireworms and a soil-injected one. Our results confirmed that some biopesticides can exert unexpected effect on non-target arthropods. However, the examined biopesticides were as empirically effected against the target arthropods regarding wireworms. Nevertheless, the application exempt from ash of the examined bioinoculants Natur Nova containingB. bassianaandM. anisopliaewere not suitable for the elimination of the stored product pests modelled byS. granarius. In contrast, the putative plant protection effect of these biopesticides was observed in the course of applying the agents in the recommended environment and pest species as well as when applying them with ash carrier.

Need for growing non-Bt cotton refugia to overcome Bt resistance problem in targeted larvae of the cotton bollworms, Helicoverpa armigera and Pectinophora gossypiella

BackgroundThe effectiveness of Bacillus thuringiensis (Bt) cotton against target arthropod larvae is decreasing day by day. The comparative effect of Bt expression among Bt cotton varieties and different plant parts was observed against the cotton bollworms: Helicoverpa armigera and Pectinophora gossypiella larvae.ResultsIn the present study, larval mortality of H. armigera was higher than P. gossypiella among selected Bt cultivars. Median lethal concentration (LC50) values were 8.91, 13.4, 14.0, and 36.4 for P. gossypiella, while 5.91, 4.04, 2.37, and 8.26 for H. armigera of FH-142, MNH-886, IR-3701, and FH-Lalazar, respectively. These values depicted that P. gossypiella had more Bt resistance problem than H. armigera larvae. The host range of both targeted insect larvae was different from each other due to the polyphagous feeding nature of the larvae of H. armigera that feed on different host plants, but P. gossypiella attacked only cotton with monophagous feeding habit. It was also notable from results that Bt expression in reproductive parts where the attacked pink bollworm was lower than the American bollworm, so the former had the maximum chance of resistance due to repeated exposure to Bt.ConclusionsIt was concluded that farmers be advised to follow the practice of growing non-Bt as a refuge crop to reduce the problem of Bt resistance in the target arthropod species.

Known Target and Nontarget Effects of the Novel Neonicotinoid Cycloxaprid to Arthropods: A Systematic Review.

Neonicotinoids are the most widely used insecticide class worldwide, and unfortunately, the widely used neonicotinoid imidacloprid is problematic for pollinators and other nontarget organisms. These nontarget impacts and the development of resistance prompt the ongoing development and testing of new neonicotinoids. The novel neonicotinoid cycloxaprid was described in 2011 and registered in China in 2015. Studies investigating its use and effect on target and nontarget species are recent and ongoing, and empirical evidence has not yet been collectively considered. Therefore, a systematic review was performed to identify and summarize data associated with target and nontarget, lethal and sublethal impacts of cycloxaprid for its use as a new insecticide. We performed keyword literature searches in Web of Science, PubMed, Academic Search Complete, and Google Scholar and explored citations used in identified articles. The search strategy yielded 66 citations; 25 citations fulfilled eligibility criteria and were included in the review. Under experimental conditions, cycloxaprid reduced populations of plant-feeding insect pests, suppressed populations of sucking and biting insect pests, and affected reproduction, development time, longevity, growth, gene regulation and expression, and phloem-feeding behavior of various life stages of certain insects. Studies focus on pest control efficacy and comparison with imidacloprid. Five nontarget organisms have been evaluated: Apis mellifera, Chrysoperla sinica, Harmonia axyridis, Daphnia magna, and Eisenia fetida. Variation in study design, to date, precludes a metaanalysis. However, these results provide valuable insight into possible effects to target and nontarget arthropods. Because cycloxaprid is a new insecticide, additional research is needed to clarify the mechanism of action of cycloxaprid and its metabolites, and to determine if it harms natural enemies or other nontarget organisms, if resistance develops, and if it exhibits cross-resistance with other insecticides. Although research on target arthropods will inform some effects on nontarget organisms, studies focusing explicitly on impacts to nontarget organisms are needed. Integr Environ Assess Manag 2020;16:831-840. © 2020 SETAC.

Management of Plant and Arthropod Pests by Deer Farmers in Florida

Abstract Deer farming is a growing livestock industry. As with established livestock farming, biting arthropod pest control is a challenge, but knowledge about pest control practices being utilized by deer farmers is limited. To fill this knowledge gap and to assess if recommended integrated pest management (IPM) programs were being used, we surveyed Florida deer farmers about their pest management programs via an online questionnaire. Of surveyed deer farmers in Florida, 94% reported using chemicals for plant and arthropod pest control. Deer farmers reported controlling biting midges, mosquitoes, horse flies, and deer flies as their target arthropods. The primary herbicide and arthropod-targeted pesticide reported were glyphosate and permethrin, respectively. Two thirds of deer farmers reported that they were concerned about pesticide resistance developing on their properties, and 72% reported utilizing resistance mitigation techniques such as alternating pesticides or using less pesticide at the start of a management routine. A majority, 66%, of deer farmers reported using a combination of control techniques. Future work should focus on best management practice development based on the study findings, as well as educational materials regarding IPM use for deer farmers. Together these tools should improve animal health and well-being on deer farms by facilitating safe and sustainable arthropod management.

Current Knowledge of the Entomopathogenic Fungal Species Metarhizium flavoviride Sensu Lato and Its Potential in Sustainable Pest Control.

Fungal entomopathogens are gaining increasing attention as alternatives to chemical control of arthropod pests, and the literature on their use under different conditions and against different species keeps expanding. Our review compiles information regarding the entomopathogenic fungal species Metarhizium flavoviride (Gams and Rozsypal 1956) (Hypocreales: Clavicipitaceae) and gives account of the natural occurrences and target arthropods that can be controlled using M. flavoviride. Taxonomic problems around M. flavoviride species sensu lato are explained. Bioassays, laboratory and field studies examining the effect of fermentation, culture regimes and formulation are compiled along with studies on the effect of the fungus on target and non-target organisms and presenting the effect of management practices on the use of the fungus. Altogether, we provide information to help conducting basic studies, and by pointing out relatively uncharted territories, help to set new research areas.

Phylogenetics and vector competence of a bovine ephemeral fever virus strain from Israel

Bovine ephemeral fever virus (BEFV) [Family Rhabdoviridae: genus Ephemerovirus] causes a transient febrile illness in cattle that results in economic losses and morbidity, with occasional mortality. Epidemics of the disease have been particularly costly in countries of the Middle East, including Israel. The virus is considered a vector-borne pathogen although the exact relationship with a number of blood-feeding arthropods has not been established. In order to improve developments in diagnostic detection, phylogeographic investigations and virus-vector relationships of BEFV we have derived the first genome of this virus from an isolate from Israel and used this to assess recent outbreaks of disease. We have also investigated the vector competence of BEFV with a number of target arthropod species. The complete genome sequence of BEFV (Israel strain 1) is 14 850 base pairs in length and shows over 95 % identity with the only other Middle Eastern genome for BEFV from Turkey. A wider phylogeny shows that these viruses form a clade, previously described as cluster II, which is clearly distinct from BEFV strains derived from China, Japan and Australia. However, there is a distinct separation of those viruses from Israel to others in the Middle East. Preliminary vector competence studies suggest that at least three species of mosquito that are potential transmission vectors of the virus are incapable of infection with, or transmission of, BEFV. Current studies are ongoing to assess other blood-feeding insect species as potential vectors.

Pesticide-Induced Stress in Arthropod Pests for Optimized Integrated Pest Management Programs.

More than six decades after the onset of wide-scale commercial use of synthetic pesticides and more than fifty years after Rachel Carson's Silent Spring, pesticides, particularly insecticides, arguably remain the most influential pest management tool around the globe. Nevertheless, pesticide use is still a controversial issue and is at the regulatory forefront in most countries. The older generation of insecticide groups has been largely replaced by a plethora of novel molecules that exhibit improved human and environmental safety profiles. However, the use of such compounds is guided by their short-term efficacy; the indirect and subtler effects on their target species, namely arthropod pest species, have been neglected. Curiously, comprehensive risk assessments have increasingly explored effects on nontarget species, contrasting with the majority of efforts focused on the target arthropod pest species. The present review mitigates this shortcoming by hierarchically exploring within an ecotoxicology framework applied to integrated pest management the myriad effects of insecticide use on arthropod pest species.

Are kaolin and copper treatments safe to the olive fruit fly parasitoid Psyttalia concolor?

Kaolin particle films and copper-based products can be considered as possible alternatives to traditional agrochemicals used for controlling the dominant pest of olive grove areas of the Mediterranean Basin, the olive fruit fly, Bactrocera oleae (Rossi) (Dip. Tephritidae), to which this pest has already evolved resistance. Psyttalia concolor (Szepligeti) (Hym. Braconidae) is a koinobiont larval–pupal endoparasitoid of many Tephritidae of economic importance. It has been routinely used in the Mediterranean Basin for augmentative releases against B. oleae. Detailed knowledge of lethal and sublethal effects of these agrochemicals on non target arthropods is required for effective integrated pest management programmes. The aims of this study were to evaluate direct mortality caused by kaolin and copper salts on the parasitoid and the sublethal effects on emergence of adults from treated pupae and on beneficial capacity of females through four different experiments, three at laboratory level and one in semi-field conditions. Dual choice and no-choice experiments in the case of kaolin were also performed to test kaolin oviposition repellence. The results indicated that the tested agrochemicals were not harmful to the parasitoid. No lethal toxicity or effects on beneficial capacity were recorded. The behavioural experiments, however, showed that when females could choose between parasitising through a kaolin-treated surface and a water-treated one, there was a slight reduction in the percentage of parasitised hosts for kaolin. No differences were detected when females were not given a choice.

Vertical stratification in arthropod spatial distribution research

Spatial heterogeneity within individual host trees is often overlooked in surveys of phytophagous arthropod abundance and distribution. The armored scale Aulacaspis yasumatsui is controlled by the predator Rhyzobius lophanthae to a greater degree on leaves at 75-cm height than on leaves at ground level within its host tree Cycas micronesica. The direct influence of elevation on the predator indirectly generates vertical heterogeneity of the scale insect. Arthropod sampling schemes that fail to include all strata within the vertical profile of the host tree species may generate misleading outcomes. Results indicate that sub-meter increments can reveal significant differences in vertical distribution of phytophagous insects, and that inclusion of observations on other organisms that interact with the target arthropod may illuminate determinants of vertical heterogeneity.

Sweeping beauty: is grassland arthropod community composition effectively estimated by sweep netting?

Arthropods are critical ecosystem components due to their high diversity and sensitivity to perturbation. Furthermore, due to their ease of capture they are often the focus of environmental health surveys. There is much debate regarding the best sampling method to use in these surveys. Sweep netting and pan trapping are two sampling methods commonly used in agricultural arthropod surveys, but have not been contrasted in natural grassland systems at the community level. The purpose of this study was to determine whether sweep netting was effective at estimating arthropod diversity at the community level in grasslands or if supplemental pan trapping was needed. Arthropods were collected from grassland sites in Montana, USA, in the summer of 2011. The following three standardized evaluation criteria (consistency, reliability, and precision) were developed to assess the efficacy of sweep netting and pan trapping, based on analyses of variations in arthropod abundances, species richness, evenness, capture frequency, and community composition. Neither sampling method was sufficient in any criteria to be used alone for community-level arthropod surveys. On a taxa-specific basis, however, sweep netting was consistent, reliable, and precise for Thysanoptera, infrequently collected (i.e., rare) insects, and Arachnida, whereas pan trapping was consistent, reliable, and precise for Collembola and bees, which is especially significant given current threats to the latter's populations worldwide. Species-level identifications increase the detected dissimilarity between sweep netting and pan trapping. We recommend that community-level arthropod surveys use both sampling methods concurrently, at least in grasslands, but likely in most nonagricultural systems. Target surveys, such as monitoring bee communities in fragmented grassland habitat or where detailed information on behavior of the target arthropod groups is available can in some instances employ singular methods. As a general ecological principle, consistency, reliability, and precision are appropriate criteria to evaluate the applicability of a given sampling method for both community-level and taxa-specific arthropod surveys in any ecosystem.

Perspectives on the potential of entomopathogenic fungi in biological control of ticks

Ticks are serious health threats for humans, and both domestic and wild animals. Ticks are controlled mostly by application of chemical products; but these acaricides have several negative side effects, including toxicity to animals, environmental contamination, and induction of chemical resistance in some tick populations. Entomopathogenic fungi infect arthropods in nature and can occur at enzootic or epizootic levels in their host populations. Laboratory studies clearly demonstrate that these fungi can cause high mortality in all developmental stages of several tick species, and also reduce oviposition of infected engorged females. Tick mortality following application of fungi in the field, however, often is less than that suggested by laboratory tests. This is due to many negative biotic and climatic factors. To increase efficacy of fungal agents for biological control of ticks under natural conditions, several points need consideration: (1) select effective isolates (viz., high virulence; and tolerance to high temperature, ultraviolet radiation and desiccation); (2) understand the main factors that affect virulence of fungal isolates to their target arthropods including the role of toxic metabolites of the fungal isolates; and (3) define with more precision the immune response of ticks to infection by entomopathogenic fungi. The current study reviews recent literature on biological control of ticks, and comments on the relevance of these results to advancing the development of fungal biocontrol agents, including improving formulation of fungal spores for use in tick control, and using entomopathogenic fungi in integrated pest (tick) management programs.

Development of a framework based on an ecosystem services approach for deriving specific protection goals for environmental risk assessment of pesticides

General protection goals for the environmental risk assessment (ERA) of plant protection products are stated in European legislation but specific protection goals (SPGs) are often not precisely defined. These are however crucial for designing appropriate risk assessment schemes. The process followed by the Panel on Plant Protection Products and their Residues (PPR) of the European Food Safety Authority (EFSA) as well as examples of resulting SPGs obtained so far for environmental risk assessment (ERA) of pesticides is presented. The ecosystem services approach was used as an overarching concept for the development of SPGs, which will likely facilitate communication with stakeholders in general and risk managers in particular. It is proposed to develop SPG options for 7 key drivers for ecosystem services (microbes, algae, non target plants (aquatic and terrestrial), aquatic invertebrates, terrestrial non target arthropods including honeybees, terrestrial non-arthropod invertebrates, and vertebrates), covering the ecosystem services that could potentially be affected by the use of pesticides. These SPGs need to be defined in 6 dimensions: biological entity, attribute, magnitude, temporal and geographical scale of the effect, and the degree of certainty that the specified level of effect will not be exceeded. In general, to ensure ecosystem services, taxa representative for the key drivers identified need to be protected at the population level. However, for some vertebrates and species that have a protection status in legislation, protection may be at the individual level. To protect the provisioning and supporting services provided by microbes it may be sufficient to protect them at the functional group level. To protect biodiversity impacts need to be assessed at least at the scale of the watershed/landscape.

Geographic Patterns of Ground-dwelling Arthropods Across an Ecoregional Transition in the North American Southwest

Abstract We examined the biogeographic patterns of ground-dwelling arthropod communities across a heterogeneous semiarid region of the Southern Rio Grande Rift Valley of New Mexico. Our 3 sites included portions of 5 ecoregions, with the middle site a transition area where all ecoregions converged. We addressed the following 3 questions: (1) Do the species assemblage patterns for ground arthropods across habitats and sites conform to recognized ecoregions? (2) Are arthropod assemblages in distinct vegetation-defined habitats within an ecoregion more similar to each other or to assemblages in similar vegetation-defined habitats in other ecoregions? (3) Is there a detectable edge effect with increased arthropod diversity in the area of converging ecoregions? We encountered 442 target arthropod species from pitfall traps operating continuously for 7 years over a series of different habitats at each of the 3 sites. We examined geographic distributions of spider and cricket/grasshopper species in detail, and t...

FORUM 'Integrated biological control': A proposal for enhancing success in biological control

It is widely recognized that the proportion of classical biological control initiatives which contribute towards the management of the target arthropod pests is lower than desired and is typically less than 10%. We argue that an important factor contributing to this relatively poor success rate is thattoo little attention is given to the requirements of the agent. Conservation biological control uses habitat manipulation techniques to enhance the impact of endemic, native-natural enemies but we show that it can also increase the impact of exotic agents. This suggests that classical biological control may more often reach its full potential when coupled with habitat manipulation techniques which ensure the agents' requirements for nectar, pollen, moderated microclimate or alternative hosts are met. Greater attention to the requirements of agents may also maximize the longevity and impact of natural enemies released in inundative (in contrast to inoculative) biological control. This concept constitutes a breaking-down of prevailing methodological boundaries. We propose the term 'integrated biological control' for this approach which, we suggest, will become increasingly important in 21st century pest management.