Entomological Research最新文献

Agricultural intensification has led to significant increases in production, but the overuse of pesticides and associated hazards pose threats to biodiversity and ecological functions. Catalase (CAT), a key antioxidant enzyme, plays a crucial role in alleviating oxidative stress by directly interacting with toxins. In this study, we identified three CAT isoforms in Tenebrio molitor (TmCAT-iso1, TmCAT-iso2 and TmCAT-iso3). These CATs possess a CAT domain, tetramer interface sites and a heme-binding pocket. We examined the expression of Tm catalases across all developmental stages and in specific tissues using quantitative real time polymerase chain reaction (qRT-PCR) experiments. Our findings demonstrate that TmCAT-iso1 and TmCAT-iso3 exhibit peak expression in young and late larval stages, respectively, whereas TmCAT-iso2 shows peak expression during the egg and pre-pupal stages. Tissue distribution analysis revealed the high expression of TmCAT-iso1 and TmCAT-iso2 in larval hemocytes, whereas TmCAT-iso3 is predominantly expressed in larval Malpighian tubules. Furthermore, injection with chlorantraniliprole significantly elevated mRNA expression levels of TmCAT-iso1, TmCAT-iso2, and TmCAT-iso3 in larval groups, compared with control groups. Our study highlights the distinct developmental stages and tissues where TmCATs are expressed. We also elucidated the effects of pesticide application on the expression of each TmCAT, revealing the physiological characteristics of CATs in response to these pesticides, which are dose- and time-dependent in T. molitor.

In insects, the production of antimicrobial peptides is considered to be the solo arm of the innate immune response. The Toll and immune deficiency pathways are two major signaling pathways that lead to the production of antimicrobial peptides as final effectors. The dynamic functions of Toll/Toll-like receptors have been thoroughly reviewed in mammals and Drosophila. During the last decade, we have attempted to clarify the immunological roles of different Toll receptor variants and their ligands in Tenebrio molitor. Accordingly, we showed that TmToll-8, −9, and −10 mRNA transcripts are induced following systemic injections of Gram-negative, Gram-positive, and fungal infections. Our data revealed harmonic expression patterns of TmToll-8, −9, and −10 throughout the developmental stages of healthy individuals and in response to infections in the examined tissues (Malpighian tubules, gut, fat bodies, and hemolymph), illustrating similar evolutionary conversions of different Toll receptor variants in T. molitor. Taken together, our findings highlight the immunological actions of TmToll-8, −9, and −10 in response to pathogenic insults in T. molitor.

Bae, J, Kim, NH, Kim, SC, Chae, KS. Declination affects geomagnetic field-modulated geotaxis in fruit flies. Entomol. Res. 2023; 53: 479–484.

In the author byline, the text “JunYong BAE¹, Na-Hyeon KIM², Soo-Chan KIM³ and Kwon-Seok CHAE^4,5” was incorrect. This should have read: “JunYong BAE^1,†, Na-Hyeon KIM^2,†, Soo-Chan KIM³ and Kwon-Seok CHAE^4,5”.

We apologize for this error.

Human babesiosis is an emerging tick-borne zoonotic disease prevalent in large parts of the world. This study aimed to examine the status of Babesia microti infection in ticks collected from small mammals captured during the nationwide survey of the Republic of Korea (ROK), 2017. Ixodid ticks from small mammals of three species, Apodemus agrarius, Crocidura lasiura, and Tscherskia triton, were used for the molecular detection of B. microti. PCR analyses amplifying 18S ribosomal RNA (rRNA) of the genus Babesia showed 8.4% of the ticks to be positive. Nucleotide sequencing of the PCR products revealed two different genotypes of B. microti, the US and Kobe-type. The US-types of B. microti were detected in ticks from small mammals of almost all study sites, whereas detections of Kobe-types were restricted to ticks from southern part of ROK. Phylogenetic analysis also indicated that each of the two types of B. microti clustered into two distinct clades. This is the first report on the presence of the US and Kobe-type B. microti in ticks collected from small mammals trapped on a national scale in ROK.

A list of species of Lepidoptera, aquatic insects, and higher plant species inhabiting 22 National parks in Korea was compiled. A similarity analysis was performed to compare all National parks, and cladograms were constructed. In the case of higher plants, those inhabiting the Hallasan region were categorized as a separate group, while the plants living in National parks located near the southern and western coasts formed one group, and other terrestrial National parks were divided into two groups as follows: the Taebaek Mountain range/adjacent mountain group and the others group. Species of Lepidoptera, which appear to be related to plants, in the Hallasan, Taebaeksan, Taeanhaean, and Bukhansan mountains were each classified independently, and those in the Hallyeohaesang, Dadohaehaesang, Naejangsan, and Byeonsanbando in the southern and western parts of Korea were classified as a single group. In case of aquatic insects, those in the Hallasan, Taeanhaean, and Bukhansan region were categorized in independent groups, and other terrestrial National parks were placed in one group with high similarity. A similarity analysis was performed through a detailed classification of the habitats in National parks revealed that marine-coastal National parks particularly showed low similarity with other mountainous National parks. In addition, other terrestrial National parks were further grouped into large and small National parks. Comparing the subject map that divided Korea into climate, vegetation, and topography, some marine-coastal National park areas were confirmed to be distinguished from other areas. Furthermore, similarity analysis revealed that Gangwon-do and Baekdu-Daegan regions in Gyeongsangbuk-do were categorized into one group with high similarity.

Thrips are serious crop pests with a worldwide distribution. The first step in the design of control methods is accurate species identification. However, the morphological identification of thrips can be complex, especially as there is morphological variation amongst individuals of the same species. Analyzing a fragment of cytochrome c oxidase subunit I (COI) has been used successfully in the identification of insects and other arthropods. Citrus is among the most important crops in the world, and Mexico is one of the largest producers. Despite this, formal reports on the species diversity of thrips found in Mexican citrus orchards are scarce. We explored the species diversity of thrips in selected citrus orchards (of Mexican orange, Key lime and Persian lime), based on morphological taxonomy and on partial sequences of COI. We analyzed 111 thrips specimens, distributed in two genera: Frankliniella, including Frankliniella insularis, Frankliniella invasor and Frankliniella occidentalis; and Scirtothrips, including Scirtothrips citri and Scirtothrips dorsalis. Frankliniella insularis and F. invasor were the most abundant species in Mexican orange (Citrus × sinensis) and Persian lime (Citrus × latofolia) orchards. Scirtothrips dorsalis was the most abundant species in Key lime orchards (Citrus × aurantiifolia). Analysis of molecular variance (AMOVA) and haplotype analyses performed on F. insularis sequences (the most abundant species) showed no significant effect of geographical origin or plant host on its genetic population structure. DNA barcoding is a valuable method to complement the morphological identification of thrips in citrus orchards, allowing more accurate identification to species level.

Body decomposition is influenced by various factors, including temperature, rainfall, body mass, and the activities of insects and carnivores in areas where carcasses are abandoned. However, the specific impact of carcass mass on the decomposition rate remains unclear. Therefore, this study aimed to compare the effects of carcass mass on decomposition rate with controlled domestic environmental conditions. Carcasses were categorized as small and large. Decomposition patterns were evaluated using a visual scatterplot to illustrate the relationship between total body scores and log accumulated degree days (ADD). To quantitatively compare decomposition rates, a linear regression model was employed to analyze differences between the two carcass groups. Regardless of carcass mass, a similar oviposition period for flies (Diptera) was observed, and the external appearance of the carcass remained relatively stable until 1.8 logADD, marking the emergence of maggots. However, decomposition dramatically accelerated after reaching 1.8 logADD, coinciding with maggots hatching from eggs and their commencement of scavenging. In contrast to larger ones, the hastened decomposition of small carcasses can be attributed to the relatively substantial volume of Diptera larvae within the small carcasses, expediting colonization and utilization. Therefore, carcass mass should factor into postmortem interval estimation based on the degree of body decomposition.

In order to clarify the prediction accuracy of eight models for predicting the peak occurrence of the first generation larvae of Dendrolimus punctatus and provide basis for the pest control, a catastrophe prediction model was established based on the peak occurrence of the first generation larvae of Dendrolimus punctatus in Qianshan City, Anhui Province from 1983 to 2016, and compared with other seven prediction models. Comparing the forecasting results in 2015 and 2016 with actual value and taking 1 head/plant as the error standard, the errors of multiple regression models with six factors as independent variables, namely, peak occurrence of pupae in overwintering generation, peak occurrence of eggs in the first generation, cumulative population in overwintering generation, peak occurrence of adults in overwintering generation, rainfall in early April and parasitic rate of Trichogrammatid in the first generation eggs of Dendrolimus punctatus, were 0.21 heads/plant and 0.23 heads/plant with accuracy rate of 100%. The errors of stepwise regression model with the same six factors were 0.23 head/plant and 0.29 head/plant. The prediction accuracy of artificial BP neural network model, Markov chain model, contingency table model, stationary time series model, and fuzzy comprehensive evaluation model was 100%, but variance period extrapolation model had an accuracy rate of 88%. The accuracy of catastrophe prediction model was related to the selection of catastrophe threshold. Comprehensive comparison of the above eight models, multiple regression, stepwise regression, artificial BP neural network, Markov chain model, stationary time series model, and catastrophe prediction model were more accurate.

This study was carried out to assess the nutritional composition of Protaetia brevitarsis larvae (Pbl) reared on different feed materials. Four different types of feed materials were used to rear Pbl prior to nutritional analysis. The results show that the new formulation of feed material enhanced the crude fat content of Pbl by 75%, compared with the control. A marked increase in unsaturated fatty acids such as linoleic acid and oleic acid, by 100% compared with the control, in Pbl reared on the new formulation of feed material was also observed.

Storage grain infestation is a critical problem, with insect pests and rodents causing economic losses and reductions in the quality of food grains and food products. It has been assessed as affecting 9% of goods in developed countries and more than 20% of goods in developing countries. The chemical insecticides used for storing products protect against insect pests, but introduce hazards associated with handling insecticides and the residues on food, which threaten nontarget organisms, and so represent a serious problem to the environment. Biorational methods are low risk, are obtained from animals, plants, bacteria and some minerals, and are segregated into microbial, plant-associated protectant and biochemical substances. This method encompasses temperature management, modified atmospheric storage, ionizing irradiation, the mixing of inert materials, pheromone traps, botanicals, insect growth regulators, entomopathogens and host plant resistance. Biorational methods have emerged as alternative or supplemental pest control methods. Biopesticides would help in preventing the use of large quantities of pesticides across the globe, thus providing residue-free food and a safe environment for living. Further investigation is needed to integrate these elements to enhance the efficacy, minimize the losses and diminish the reliance on pesticides for the preservation of stored commodities.