Journal of Insect Science最新文献

Semiochemicals are chemicals that mediate inter- and intraspecific interactions between insects. Recently, these chemicals have begun to be investigated as an alternative for the management of the Central American locust, Schistocerca piceifrons piceifrons (Walker, 1870), a pest that can cause substantial damage to crops, pastures, and native vegetation. A suitable method for investigating the range of semiochemicals present in Central American locust is surface washing in organic solvents. In the work described here, the extraction of chemical compounds was carried out with hexane in a 1:10 (w/v) ratio, in 2 resting periods (1 and 24 h) and 2 stages of Central American locust development (young adult and adult in reproductive stage). By Gas Chromatography-Mass Spectrometry, 17 chemical compounds previously identified with semiochemical potential in other insects were detected. The study of semiochemicals in Central American locust offers the opportunity to identify specific chemical compounds that may have the potential to implement management alternatives for this pest. Specific studies of each compound detected in this work are needed to elucidate whether they have semiochemical activity and potential to combat the pest and reduce the environmental damage caused by the application of synthetic chemical products.

Mitochondrial genomes are a rich source of data for various downstream analyses such as population genetics, phylogeny, and systematics. Today it is possible to assemble rapidly large numbers of mitogenomes, mainly employing next-generation sequencing and third-generation sequencing. However, verification of the correctness of the generated sequences is often lacking, especially for noncoding, length-variable parts. Here we have assembled the mitochondrial genome (mitogenome) from four specimens of Agabus bipustulatus (L.) using long-read nanopore sequence data. The use of the latest nanopore chemistry (V14) combined with a comprehensive error correction workflow enabled the generation of mitogenomes with high accuracy and reproducibility, as tested on four samples. The resulting mitogenome is 17,876 bp long, including 13 protein-coding genes, 22 transfer RNA genes, 2 ribosomal RNA genes, and a control region. Differences in the control region length between samples were minimal. The arrangement of protein-coding genes, transfer RNAs, and ribosomal RNAs is similar to that of the ancestral insect mitogenome. Finally, we used the assembled, well-supported mitogenomes in the phylogenetic analysis of a part of the Dytiscidae related to the studied species and confronted the results with previous hypotheses. Conflicting estimates of their phylogeny suggest that considerably more robust data are required for a plausible sketch of their evolutionary history. Our research has confirmed that readily available third-generation sequencing technologies, such as Oxford Nanopore Technologies, combined with long-read sequencing, offer a highly efficient, reliable, and cost-effective approach to generate complete mitogenomes and potentially other longer regions of the genome. The use of reliable data will ultimately contribute to a deeper understanding and improved conservation strategies for diving beetles and other organisms.

The olive fruit fly, Bactrocera oleae (Rossi), is the most important widespread pest in olive-growing areas worldwide, causing significant yield losses and deterioration of olive oil quality. This study hypothesized that olive cultivars differ in their susceptibility to B.oleae and that the cultivar in which the pest develops may affect population variability. The primary goal was to assess susceptibility across 6 olive cultivars, while the secondary goal was to analyze population variability using geometric morphometrics to identify cultivar-specific phenotypic differences. Conducted at 2 sites, Banjevci (Dalmatia) and Vodnjan (Istria), the study revealed significant differences in infestation levels, emergence, and wing morphology. Higher humidity in Vodnjan favored increased fly populations. Larger-fruited cultivars such as Oblica, Istarska bjelica, and Ascolana tenera experienced higher infestation rates, whereas smaller-fruited cultivars like Frantoio and Leccino exhibited lower infestation levels. Wing shape analysis highlighted sexual dimorphism, with female flies exhibiting broader wings that may enhance dispersal and oviposition efficiency, particularly in larger fruits. The observed phenotypic plasticity of B. oleae across cultivars and locations indicates an ability to adapt to varied host and cultivation conditions, enhancing pest resilience. The findings underscore the role of cultivar selection as a passive pest management strategy and demonstrate the utility of geometric morphometrics in capturing cultivar-specific morphological adaptations.

Insects perceive and respond to carboxylic acids (CAs), amines, and aldehydes primarily via conserved ionotropic receptors (IRs). These receptors form the basis for a second olfactory system distinct from the well-characterized odorant receptors. Neurons expressing IRs are housed in dedicated sensilla and innervate glomeruli, separate from those innervated by odorant receptor neurons. The IR8a co-receptor is highly conserved across insect orders and, together with ionotropic receptor tuning receptors, primarily detects CAs. The conservation of genes and the anatomical separation of neural pathways underscore the importance of these compound classes and CAs, specifically in insect chemical ecology. We provide a summary of carboxylic acid detection in insects, focusing on dipteran and lepidopteran species of significance to public health and agriculture. An overview of insect behavior toward CAs is provided, as well as a comprehensive update on carboxylic acid receptor function in insects. Phylogenetic analysis of publicly available genome databases reveals several species that encode and express homologs of previously deorphanized carboxylic acid receptors, highlighting avenues for future research.

Radio frequency identification (RFID) technology and marker recognition algorithms can offer an efficient and non-intrusive means of tracking animal positions. As such, they have become important tools for invertebrate behavioral research. Both approaches require fixing a tag or marker to the study organism, and so it is useful to quantify the effects such procedures have on behavior before proceeding with further research. However, frequently studies do not report doing such tests. Here, we demonstrate a time-efficient and accessible method for quantifying the impact of tagging on individual movement using open-source automated video tracking software. We tested the effect of RFID tags and tags suitable for marker recognition algorithms on the movement of Argentinian wood roaches (Blapicta dubia, Blattodea: Blaberidae) by filming tagged and untagged roaches in laboratory conditions. We employed DeepLabCut on the resultant videos to track cockroach movement and extract measures of behavioral traits. We found no statistically significant differences between RFID tagged and untagged groups in average speed over the trial period, the number of unique zones explored, and the number of discrete walks. However, groups that were tagged with labels for marker recognition had significantly higher values for all 3 metrics. We therefore support the use of RFID tags to monitor the behavior of B. dubia but note that the effect of using labels suitable for label recognition to identify individuals should be taken into consideration when measuring B.dubia behavior. We hope that this study can provide an accessible and viable roadmap for further work investigating the effects of tagging on insect behavior.

Asian longhorned beetle (Anoplophora glabripennis Motschulsky), a wood borer (Coleoptera: Cerambycidae) native to China, has been unintentionally and repeatedly introduced to North American and European landscapes as a stow-away in the wood packing material commonly used in international trade. Asian longhorned beetle causes extensive damage and mortality in multiple deciduous tree species and in response, countries in both North America and Europe have adopted policies of eradication. Models that integrate patterns of Asian longhorned beetle dispersal with records of infested trees are critical in optimizing survey and eradication efforts and tracking eradication progress. While these tools continue to be developed, they have been limited by the availability of experimental dispersal data. Existing data is restricted to observations made in the beetle's native range in China or based on inference of dispersal in invaded landscapes. Direct observation of beetle dispersal behavior in invaded landscapes could provide critical behavioral information, but the experimental release of gravid females has been incompatible with eradication program efforts. To fill this knowledge gap, there is a need to identify field-portable methods of effectively sterilizing mated females that do not alter ovipositional behavior. Here, we present a protocol for cauterizing a beetle's ovipositor to prevent successful oviposition. Results of lab trials demonstrate the efficacy of ovipositor cauterization in inhibiting successful oviposition without altering the egg-laying behavior of gravid Asian longhorned beetle females. This method enables research to inform models of beetle dispersal and infestation risk without adding to actual or perceived risk of exacerbating infestations in an eradication program.

The granulate ambrosia beetle, Xylosandrus crassiusculus (Motschulsky), and the black stem borer, Xylosandrus germanus (Blandford) are important pests in ornamental nurseries in the eastern USA. These beetles are managed mainly using preventative trunk applications of pyrethroids, such as permethrin or bifenthrin when females typically fly out of woodlots and attack young trees in the spring. Verbenone and methyl salicylate are potential phytochemicals reported as repellants but not completely validated in ornamental nurseries for ambrosia beetle management as an alternative option. Thus, this study aimed to compare the efficacy of verbenone alone or with methyl salicylate and permethrin on ambrosia beetle attacks. In 2023 and 2024, a study was conducted where verbenone (with methyl salicylate) and permethrin were combined with 10% and 50% ethanol-infused maple bolts. Verbenone alone or combined with methyl salicylate did not reduce ambrosia beetle attacks on bolts compared to permethrin. Permethrin was effective in reducing ambrosia beetle attacks on bolts. This suggests that permethrin is still the best option to prevent ambrosia beetle attacks on young trees in ornamental nurseries.

The fall armyworm, Spodoptera frugiperda J.E. Smith (Lepidoptera: Noctuidae), is a well-known agricultural pest in North and South America and has invaded Africa, the Far East, and Australia in the past decade. To investigate the integrated management of S. frugiperda, the sublethal impacts of emamectin benzoate were studied. Leaf-dipping bioassays were used to investigate the effects of sublethal (LC10 and LC30) concentrations of emamectin benzoate on S. frugiperda demographic parameters, and data were interpreted based on the age-stage, two-sex life table theory. The results showed that the developmental time of larvae was prolonged while the fecundity decreased after sublethal concentration treatment. Furthermore, the intrinsic and finite rates of increase, as well as the net reproductive rate, significantly declined following LC30 concentration exposure, whereas the average generation time was extended in comparison to the control group. The intrinsic rate of increase (rm) dropped to 0.14 (LC10) and 0.13 (LC30)/day, compared to the control group (0.18/day). The net reproductive rate (R0) dropped from 775.40 to 303.10 and 193.30 after the LC10 and LC30 concentration treatment, respectively. In this study, sublethal concentrations of emamectin benzoate adversely affected the developmental time, fecundity, and life table parameters of S. frugiperda.

Navel orangeworm, Amyelois transitella (Walker), is a key pest in California's almonds, pistachios, and walnuts. This insect's strong dispersal capacity can potentially undermine the efficacy of localized management efforts. The timing and extent of A. transitella movement between orchards remain unclear, and more studies are needed to better characterize its landscape ecology. Mark-release-recapture studies offer a potential solution but require a reliable insect marker that is durable, easily identifiable and has minimal impacts on A. transitella longevity and flight ability. To address this, we evaluated 4 colors (red, blue, green, and yellow) of a fluorophore marker (SmartWater) for adult A. transitella. We conducted laboratory assays to assess moth flight ability and mortality, as well as marker persistence over time using both quantitative (plate reader) and qualitative (visual observation) fluorophore detection methods. Results demonstrated that none of the 4 colors negatively affected A. transitella flight ability or mortality. Green and yellow markers were persistent and readily identified by both detection methods, unlike blue and red markers. Although marker degradation was observed over time with the quantitative method, a high percentage of moths (70.3%) retained green and yellow markers after 14 days. In contrast, these markers did not show significant degradation using the qualitative method, with over 94.2% of moths showing fluorescence 14 days postmarking. These findings highlight the strong potential of green and yellow markers for field studies with A. transitella. We discuss their use in future mark-release-recapture studies and compare the 2 fluorophore detection methods.

Death-feigning, or thanatosis, is an anti-predator behavioral strategy in many animals. Because individuals remain immobile while feigning death, individuals with longer durations of death feigning often show lower locomotor activity. Thus, metabolic rate, which is closely related to locomotor activity, may also be related to the intensity of death feigning. If there is a genetic correlation between death feigning and metabolism, metabolic rate may respond to selection on death-feigning behavior. Here, we tested for a relationship between metabolic rate and death-feigning using replicated populations of the red flour beetle (Tribolium castaneum) subjected to artificial bidirectional selection on the duration of death-feigning behavior. The results indicated that metabolic rate did not differ between populations selected for increased or decreased death feigning, although locomotor activity was significantly different between these treatments; populations selected for reduced death-feigning durations tended to be more active. These results suggest that death-feigning behavior is not genetically correlated with metabolic rate in T. castaneum.