Journal of Asia-pacific Entomology最新文献

We present observations on Melittobia sosui Dahms chewing ability, courtship and egg-laying behaviors. Under laboratory conditions and with 12 tested different hosts, the parasitoid took a successful chewing on cocoons of four Sphecidae wasps and puparia of Drosophilidae and Muscidae flies. The highest successful chewing proportion was 83.3% on Chalybion bengalense (Sphecidae) cocoons. During courtship, the male mounted the female^’s back by grasping her pronotum with his forelegs, his hindlegs straddling her abdomen, his midlegs raising upwards, and clasping the female’s antennal tips into his antennal scapes. The male tapped his midlegs on the female^’s midlegs or pronotum, shook his antennae and simultaneously fluttered the wings. A male of M. sosui could courtship many females, even female pupae. After feeding on hemolymph exuded from the wounds made by her sting, the physogastric female laid batches of eggs. To oviposit, the female extended her legs to the sides and her wings were raised to an angle of about 45^° from the body. She exposed and lowered her ovipositor often perpendicular to the host surface and laid eggs; after each oviposition her abdominal apex was slightly raised upwards.

Ladybugs (Coccinellidae) are commonly known for their beneficial roles in insect pest population suppression. Despite their importance and the limited scientific research conducted in Cambodia, the ladybug fauna needs to be documented in the country. Therefore, this study aims to establish the first checklist of Cambodian ladybug fauna including a brief taxonomic description and distribution for each species. We identified a total of 13 species based on the specimens deposited in the collection of Cambodian Entomology Initiatives. 9 of all species are newly recorded for Cambodia. Within this addition and six previously recorded species, ladybugs reached 15 species recorded from Cambodia. However, many new species are under-discovered in the country. The study provided a valuable baseline checklist for the taxonomy, diversity and ecology of ladybugs in Cambodia.

Previously we suggested the significance of some of the hymenopteran (Andrenidae, Apidae, and Halictidae) and dipteran (Syrphidae) families in Japanese pear pollination. However, they might contribute differentially to the pollination reflecting their pollination efficiencies. For this study, we investigated the pollination efficiency of three insect pollinator groups at an insect-pollinated Japanese pear orchard: Apis mellifera (Hymenoptera: Apidae), solitary bees (Hymenoptera), and flies (Diptera). First, we examined the contribution of the insect pollinator groups to the fruit-set ratio of inflorescences. Results indicated that the floral visits of A. mellifera had a positive effect on the fruit-set ratio. Then, for two consecutive years, the numbers of Rosaceae pollen grains deposited on the stigma after a single floral visit by insects were examined. The obtained results were not consistent, but data in one year showed that A. mellifera and Andrena spp. (Hymenoptera: Andrenidae) deposited more pollen grains than Panurginus crawfordi (Hymenoptera: Andrenidae) did. Third, we examined the presence of pollen grains derived from the pollinizer variety among those removed from the body surfaces of the flower-visiting insects. Results indicated the involvement of the three pollinator groups in pollen grain transfer of the pollinizer variety. Finally, we recorded the abundance of flower-visiting insects by walking around the study site. Results demonstrated that flies were observed stably irrespective of temperatures during the survey period, unlike A. mellifera and solitary bees, which exhibited little flower-visiting activity under low temperatures. Results also demonstrated that solitary bees were abundant at the study site in the late flowering period. These results suggest that hymenopterans and dipterans contribute differentially but mutually complementarily to open insect pollination in the Japanese pear orchard.

Tribolium castaneum (Herbst) is a pest that threatens global grain and cereal production. Previous studies have shown that insect metabolism can be influenced by the gut microbiome. However, comprehensive research on the gut microbial population and dominant bacterial flora in T. castaneum is lacking. This study aims to examine the gut microbiota of T. castaneum using microbiome analysis and analyze its impact on the insect's metabolism through metabolome analysis. The microbiota diversity in adult T. castaneum was found to be higher than that in the larva group. Functional analysis revealed that the gut bacterial community is associated with metabolic pathways such as alanine, glutamine and glutamate, arginine and proline, tyrosine, and carbohydrate metabolism based on Tax4fun prediction. Meanwhile, metabolomics analysis of T. castaneum adults and larvae identified 141 differentially abundant metabolites (DAMs), including 126 up-regulated and 15 down-regulated metabolites. These DAMs were enriched in pathways including the tricarboxylic acid (TCA) cycle, arginine biosynthesis, alanine, aspartate and glutamate metabolism, and tyrosine metabolism. Additionally, correlation analysis showed significant relationships between the gut microbiota and metabolites. These findings enhance our understanding of the gut microbiota in T. castaneum and provide insights for the development of more effective strategies in controlling stored-product insect pests.

The present study investigated the immune regulatory mechanisms of Poria cocos polysaccharides (PS) in a cyclophosphamide (CTX)-induced immunosuppression silkworm model. We found that PS increased the superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH-Px) activities, as well as reactive oxygen species (ROS) levels in the fat body or haemocytes of CTX-treated silkworms. PS also strongly stimulated the immunity of silkworms by increasing haemocyte counts and PO activity and upregulating the mRNA expression of immune-related genes. We further investigated the metabolic profile of the fat body after PS treatment using  liquid chromatography–massspectrometry/mass spectrometry (LC–MS/MS) and identified 236 differentially expressed metabolites. Among them, nine metabolites related to amino acid metabolism were present at high levels in the PS-treated group, whereas the contents of metabolites involved in sphingolipid metabolism and alpha-linolenic acid metabolism were significantly decreased after PS treatment. The amino acid metabolism pathways and lipid metabolism pathways were found to be significantly altered in the PS-treated group, which indicates that PS may regulate the immune system of silkworms by reprogramming lipid and amino acid metabolism. This study provides new insight into the immune regulatory effect of PS in animals.

Cuticular hydrocarbons (CHCs) are the main components of the wax layer present on insects’ surface, serving as protective agents against environmental stress and/or as communication signals. It has been documented that the chemical composition of CHCs varies with species and even with developmental stage or sex of the same species. However, studies involving in a life-cycle identification of CHCs are rare. In this work, we attempted to profile the components and relative abundance of CHCs in the cotton bollworm Helicoverpa armigera at all the four developmental stages and in both sexes of pupae and adults. A total of 29 CHCs were putatively identified by gas chromatography-mass spectrometer analysis, including 14 n-alkanes, 4 methyl-branched alkenes and 11 methyl-branched alkanes, with 15 of them being detected at all the four developmental stages. Of the 29 CHCs, the straight-chain alkanes with 27, 29 and 31 carbon atoms were the major CHCs. All three classes of CHCs (n-alkanes, methyl-branched alkanes and methyl-branched alkenes) were found in both larvae and pupae, while no unsaturated hydrocarbons were observed in eggs and adults. Methyl-branched alkanes were the main component found in eggs and adults, while the composition of n-alkanes and methyl-branched alkanes in larvae and pupae varied with ages. Principal component analysis (PCA) revealed that the CHC profiles in larvae and adults changed significantly with ages, while the CHC profiles in early pupae (1-day-old) showed distinct difference from those of late pupae. Furthermore, sexual dimorphism in the CHC profile was observed in mature adults (3-day-old and 5-day-old), with male adults possessing more n-C31 and n-C33, but less 3-MeC29 than females.

Only two species in the tortricid genus Lepteucosma Diakonoff, 1971 is currently recognized, namely L. ceriodes (Meyrick, 1909) and L. shikokuensis (Kawabe, 1984) in Taiwan. Two new species, Lepteucosma blandoides Lu & Hsu, sp. nov. and Lepteucosma dasyueshanensis Lu & Hsu, sp. nov., are found in Taiwan and being described. The key to the Lepteucsoma species in Taiwan is provided, and a checklist of the genus of the world is also given. We also propose a new combination, Lepteucosma yoshiyasui (Kawabe, 1989) comb. nov., based on the genitalia and wing characters. The results of this study increase the number of the Lepteucosma species to 24. Finally, we advocate paying more attention to the insects inhabitng the alpine area of Taiwan.

www.zoobank.org/urn:lsid:zoobank.org:pub:10C030E6-905B-4AA5-8595-123AA0290241.

The detrimental effects of agricultural pesticides on human and environmental health necessitate the development of alternatives to conventional pesticides. In the laboratory, the cotton leafworm (Spodoptera littoralis) and aphid (Aphis gossypii) insects were used to evaluate the insecticidal activity of bio-oil derived from olive cake. The application of bio-oil by leaf dipping against S. littoralis demonstrated no mortality at a concentration of 1 % bio-oil. In contrast, the bio-oil showed better results against A. gossypii by slide dip method with LC₅₀ = 1310.40 mg/l and LC₉₀ = 3117.40 mg/l. The combined activity of bio-oil and the biopesticide Beauveria bassiana (bio-oil/B.b) was comparable, with LC₅₀ = 1386.94 mg/L and LC₉₀ = 3142.05 mg/L. The field application (two sprays) of bio-oil, bio-oil/B.b, and a commercial insecticide (alpha super) on aphids revealed a reduction of 52 %, 74.33 %, and 74.67 % in the first spray and 59.67 %, 63.33 %, and73.67 % in the second spray for, bio-oil, bio-oil/B.b, and super alpha respectively. The bio-oil and bio-oil/B.b had significantly less effect on the population densities of two predators (predator mite Amblyseius swirskii and aphid lion Chrysoperla carnea) than the insecticide used. Analyses of bio-oil by gaschromatography–mass spectrometry (GC–MS) identified 30 compounds possibly have pesticidal activity. The most abundant compounds are 9 octadecenoicacid methyl ester, hexadecanoic acid, methyl ester, 6 octadecenoic acid, methyl ester and Phenol, 2methoxy. The pyrolysis byproduct (bio-oil) of olive cake biomass contains bioactive compounds that can be used as biopesticide.

The diamondback moth (DBM) is involved in great amount of predominant gut bacterium Enterococcus mundtii. Radish seedlings and cabbage leaves are natural suitable foods to feed the pest in laboratory. Leaf microbiome could be reshaped by insect herbivory. In this study, phyllosphere bacterial composition on radish seedlings with and without DBM herbivory in the chamber, and on cabbage leaves in the field with no DBM herbivory were investigated by high-throughput sequencing technology. Results showed that Proteobacteria and Bacteroidota were two common predominant phyla for both radish seedlings and cabbage leaves, while Firmicutes was only detected in phyllosphere of radish seedlings. Pseudomonas was the only common shared phyllosphere genus; Alkanindiges and Delftia were the unique dominant bacterial genera in cabbage and in radish, respectively. More bacterial varieties and higher bacterial community diversity was also found in cabbages leaves than that of radish seedlings. The bacterial community diversity and richness in radish seedlings fed by DBM was higher than that of not fed. Gut bacterium Enterococcus was only found on radish seedlings leaves that fed by DBM, while neither in radish seedlings nor in cabbage leaves not fed by the pest. As one survey in origin of predominant gut bacterium Enterococcus from DBM, this study offers new insights into the phyllosphere bacterial composition and diversity from the feeding food of DBM in field cabbage leaves and in laboratory radish seedlings.

Several Coleoptera fossils, including Coptoclavidae, Elateridae, Ommatidae, and Staphylinidae, were previously described from the Jinju Formation (Albian), South Korea. However, numerous beetle fossils require further research to fully understand the biodiversity of this important Cretaceous deposit. In this study, we present an overview of the diversity of Coleoptera from the Jinju Formation. Future studies on beetles of the Jinju Formation will be divided into several parts corresponding to the major lineages found in this Albian deposit. In this first part, we introduce the geological context, review previous studies related to Coleoptera fossils from the Jinju Formation, and present specimens that will undergo detailed examination in subsequent papers.