Journal of Asia-pacific Entomology最新文献

Supercritical fluid extraction (SFE) is a rapid, selective, and convenient method for sample preparation prior to the analysis of compounds in a volatile product of plant matrices. In this study, insecticidal activity and repellency were examined in a laboratory study to determine the active constituent of Chamaeparis obtusa and a supercritical fluid extract from Chamaeparis obtusa against hard tick Haemaphysalis longicornis.

The repellency of C. obtusa oil was evaluated in comparison with two commercial repellents (Icaridin and DEET) against H. longicornis. Filter-paper diffusion assay revealed that C. obtusa oil (3.2 µg/cm²) had a 100 % repellency and icaridine (3.2 µg/cm²) had a 96.1 % repellency at 120 min. Repellencies of 31 compounds against H. longicornis were compared with the repellency of DEET at 3.2 µg/cm². Responses varied according to the test compound and exposure time. Repellencies of α-terpinene, terpinene-4-ol, and α-terpineol were 100 % at 30 min post-treatment. They were 85.5 %, 56.4 %, and 68.9 %, respectively, at 120 min. C. obtusa oil, α-terpinene, terpinene-4-ol, and α-terpineol merit further study as potential fumigants or lead compounds for the control of H. longicornis.

The tomato leafminer, Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae), is a highly destructive insect pest in Solanaceae, particularly in tomato crops. In this study, bacteria symbionts of eggs, the whole body, and different tissues of the fourth instar larvae of two populations, Rasht and Karaj, were isolated and identified. Using the 16S rRNA procedure, all symbiont bacteria, whether cultured or non-cultured, were classified at the phylum level as Proteobacteria and Firmicutes. BLASTn analyses revealed an overlap of Wolbachia, Enterobacter, Pseudomonas, Staphylococcus, and Acinetobacter genera in both populations. However, Bacillus subtilis, and Serratia marcescens were found only in Rasht, while Paenibacillus sp. and P. pasadenensis were identified solely in the Karaj population. Phylogenetic analysis of all bacterial sequences, except Wolbachia, revealed a distant evolutionary relationship between the leafminer's symbionts and those of other lepidopterans. Thus, we could demonstrate the microbiota diversity of this insect pest across different locations. Furthermore, this research will provide insights for discovering new biorational control methods for T. absoluta based on the parasitic or mutualist symbionts.

Organism size significantly influences various aspects of physiology and ecology. In insects, body size can be assessed using parameters such as wing length, thorax width, abdomen length, and body weight. Among Lepidoptera, wing length is a commonly used metric for measuring body size, although obtaining data on body weight can be challenging. The relationship between wing length and body weight of moths was examined based on the samples collected from three mountain areas in southern Korea, Mt. Hallasan (HL), Mt. Jirisan (JR), and Mt. Seungdalsan (MN) from June to October 2020. The study aimed to investigate the relationship between wing length and body weight and whether this relationship varied at the moth families and study sites. In addition, we investigated whether the body size depended on the elevation. We collected a total of 366 species and 1,356 individual moths across 17 families. The regression power for the combined taxa across all areas was 3.05 (±0.05 S.E.) and the regression power was high on the island mountain and this increased as the elevation rose. No significant association across the three mountains between body size and elevation, while the species-rich families such as Geometridae, Noctuidae, and Notodondidae showed different relationships across mountains.

The cotton or melon aphid (Aphis gossypii Glover) is one of the most important agricultural insect pests worldwide. Many populations of this pest have been documented to be resistant to multiple classes of insecticides in Xinjiang Uygur Autonomous Region of China. Understanding the molecular mechanisms behind resistance in field populations is crucial for making effective strategies for control of this pest. In this study, we investigated potential genetic mutations responsible for insecticide resistance in two insecticidal targets in four cotton aphid populations in Xinjiang. Our data showed that the classical A2′S mutation in the γ-aminobutyric acid (GABA) receptor RDL1 was present in the cotton aphid at frequencies ranged from 4.5 % to 50 %, indicating that the cotton aphids have evolved the Rdl-based mechanism of resistance to synthetic insecticides via a parallel mutation in Rdl1 even in the genetic background with the 2ʹS-carrying duplicated Rdl (Rdl2). In addition, three mutations (A302S, A332V and S431F) in the acetylcholinesterase AChE1 were found to be prevalently distributed in A. gossypii populations. Notably, the resistant 431F allele was fixed in the four examined populations, and all existing ace-1 alleles were resistant, carrying either one or two of the three mutations. The occurrence of resistance-conferring mutations in multiple insecticidal targets warns a risk of failure in aphid control using chemical insecticides in Xinjiang, the major cotton planting region of China.

In this study, we report a new species of the genus Elasmus Westwood (Hymenoptera: Eulophidae). The new species parasitizes two different unidentified Oiketicinae species of bagworm moths (Lepidoptera: Psychidae) and shows both solitary and gregarious traits. A description of the new species Elasmus psycheae n.sp. is provided in addition to figures and information about the biology. In addition, a key to the species of this genus from Korea is also presented.

www.zoobank.org/urn:lsid:zoobank.org:pub:17C2AA8B-4017-44BC-A44D-BD45746EC387.

Although the species Povilla heardiHubbard, 1984 was described from both males and putative nymphs, no photographic structures were presented, and this species was not found in China before. In 2023, dozens of adults were trapped and reared from nymphs in southwestern Chinese Yunnan Province. Detailed descriptions and photographs of them confirmed the synonym Povilla junki to P. heardi, and represent the first nymph-adult association of Asian species in the genus. In addition, our findings represent the first record of Asthenopodinae in this country, widened the Northern distribution of Povilla, and provide some biological information for this poorly known species.

ZooBank LSID: urn:lsid:zoobank.org:pub:392A0D37-258B-4662-A318-BA671654E093.

Genus Sinodima Kundrata, Sormova & Qiu, 2019 was originally described based on a single species represented by the female holotype. In this study, we examined more than 500 specimens of Sinodima collected using Malaise traps. As a result, we described two new species from China: Sinodima liupanshuiensis sp. nov. and Sinodima nanlingensis sp. nov. The males of this genus are firstly reported and distinctly differentiated from the females by the elongate body and fully developed hind wings. Two new combinations are proposed for species originally described in genus Penia Laporte, 1838: Sinodima elongata (Arimoto, 2023), comb. nov. and Sinodima sucinea (Schimmel, 2001), comb. nov. The newly discovered Sinodima species provide the first report on strong sexual dimorphism in Dimini and highlight an unusual season activity of adults during autumn to early winter.

Sogatella furcifera is a typical r-strategist insect with strong adaptability and one of the major pests in rice cultivation. Small heat shock proteins (sHsp) play a vital role in insects responding to external abiotic stress. However, little is known about the role of sHsp in the defense against abiotic stress in S. furcifera. In this study, four sHsp genes (SofHsp20.7, SofHsp21.6, SofHsp21.7, and SofHsp21.8) were identified from S. furcifera, and their gene expression patterns were analyzed at different developmental stages, temperature stress, insecticide exposure, and UV-A irradiation. The results indicated that four sHsp were expressed at various developmental stages of the S. furcifera, with the highest transcription levels in the first-instar nymphs, fourth day fifth instar nymphs, third-day adult females, and eggs, respectively. High-temperature stress (30 °C and 40 °C) significantly induced the expression of all four sHsp genes, while low-temperature stress (10 °C) reduced their expression. Sublethal concentrations (LC₁₀ and LC₂₅) of buprofezin increased the expression levels of SofHsp20.7 and SofHsp21.8. Under UV-A irradiation, the S. furcifera also significantly induced the expression of all four sHsp genes, with the highest expression observed at 90 min after exposure to the stress. These results suggest that sHsp genes are essential for the resistance or tolerance of S. furcifera to high temperature, buprofezin, and UV-A irradiation. This research provides a foundation for understanding the molecular mechanisms underlying the S. furcifera adaptation to abiotic stress.

The red-necked longhorn beetle Aromia bungii (Coleoptera: Chrysomeloidea: Cerambycidae) is a wood-boring pest of Prunus spp. We analyzed two complete mitochondrial genomes of A. bungii collected in South Korea. The complete mitochondrial genomes were 15,759 bp and 15,760 bp long, including a typical set of genes (13 protein-coding, 22 transfer RNA, and two ribosomal RNA genes) and one non-coding region. Phylogenetic analysis revealed that the two mitochondrial genomes of A. bungie clustered with previously reported three mitochondrial genomes from China in one clade and was a sister group to Closteromerus belonging to the tribe Callichromatini.

Myocyte enhancer factor-2 (MEF2) plays essential roles in a variety of developmental processes. Prominent amongst multiple MEF2 functions is the regulation of muscle differentiation in Drosophila melanogaster. Nevertheless, the physiological importance of MEF2 has not been explored in non-Drosophilid insect species. Here we found HvMef2 was highly expressed at the first-instar larvae, 0-day-old second- and fourth-instar larvae, pupae and adults, especially in adult muscle in a Coleopteran potato defoliator Henosepilachna vigintioctopunctata. Injection of 200, 500 or 1000 ng of dsMef2 into the third instar larvae significantly reduced the expression of HvMef2 and impaired larval-pupal-adult transition, in a dose-dependent manner. About 68 %, 77 % and 87 % of the resulting larvae arrested as stunted prepupae, which were gradually blackened and eventually died. Around 32 %, 23 % and 13 % of the HvMef2 depleted beetles formed pupae. Among these HvMef2 depleted pupae, 22 %, 16 % and 7 % became shriveled pupae until death; roughly 10 %, 7 % and 6 % emerged as malformed adults. The growth of the adult thorax muscles was repressed. The length and width of dorsal–ventral muscles were significantly reduced. Knockdown of HvMef2 at the fourth larval instar stage caused similar defects. Likewise, introduction of dsMef2 at a dose of 200, 500 or 1000 ng into pupae led to 27 %, 20 % and 11 % emergence percentages respectively, with deformed elytra and hindwings. Therefore, MEF2 plays vital roles during metamorphosis, especially in myogenic regulation network in H. vigintioctopunctata.