Entomological Science最新文献

The extremely rare jewel beetles of the genus Tokaranodicerca Hattori (Coleoptera: Buprestidae) are distributed in isolated and small areas in and near villages in Japan and Vietnam, raising immediate conservation concerns. The present study investigated the molecular phylogeny among Tokaranodicerca and related genera (Dicerca and Touzalinia) using mitochondrial and nuclear DNA sequences as the fundamental knowledge for conservation. The phylogenetic analyses revealed that the genus Tokaranodicerca formed a monophyletic clade and was sister to the genus Touzalinia, which is consistent with the previous phylogenetic study based on morphology. The two Japanese species, Tokaranodicerca nishidai and Tokaranodicerca shimonoi were genetically distant from each other despite their close distribution areas and similar biology, particularly their association with aged Morus trees, indicating that they should be treated as different conservation units. In addition, the morphology of Vietnamese species Tokaranodicerca vietnamensis, which was not examined in this study, is more similar to that of T. shimonoi than T. nishidai. Therefore, the presence of undescribed Tokaranodicerca species is expected in East Asia. For conservation of Tokaranodicerca, protection of rural forests containing thick-trunked, aged Morus trees in East Asia is important.

Drosophila moriwakii (Diptera: Drosophilidae) generally has one generation in a year and enters summer–winter reproductive diapause in early summer in Sapporo, northern Japan, but a small fraction of the population produces the second generation in mid-summer at places where breeding resources are abundantly provided. In the laboratory experiments, flies were revealed to enter diapause under moderately low temperatures and short daylengths. Under long daylengths, they enter diapause when reared in cages in which they are able to fly freely but do not when reared in small vials in which they are prevented from flying. However, the effect of diet on diapause has not been investigated in the laboratory. In this study, we address this issue by using artificially prepared breeding resources made of Drosophila medium, apple juice and dry yeast. In the results, females of this species were prevented from entering diapause not only when they were fed with these resources but also when they were exposed only to the odor of fermenting apple juice.

The Guineo-Congolian forests, extending from Sierra Leone to Uganda, are recognized as one of the most biodiverse regions on Earth. Species distribution in these forests follows distinct patterns, including interconnected species with minimal genetic differentiation, species complexes with distribution gaps, and species with continuous ranges undergoing speciation. This study explored distribution patterns in the flower beetles of the genus Dicronorhina, especially D. cavifrons, D. m. micans, and D. johnstoni. From field surveys conducted in Côte d'Ivoire, Togo, Nigeria, Uganda, and South Sudan, we examine adult phenology, habitat characteristics, and the biogeographic implications of these species. We examine habitat use at both sighting and landscape scales using geographic information system–based spatial analyses, detrended correspondence analysis, and linear mixed methods. We show that within this species complex, D. cavifrons and D. m. micans display similar ecological traits. At the same time, D. johnstoni has distinct adaptations, including a broader habitat range and reduced reliance on mature forests. Rainfall positively influenced the activity of D. cavifrons and D. m. micans, though its effect on D. johnstoni was unclear. Intraspecific variation was minimal, while interspecific differences highlighted divergent ecological pathways. Biogeographically, the Volta River was hypothesized to act as a barrier, isolating D. cavifrons from D. m. micans, while D. johnstoni occupies a unique niche.

Parthenogenetic species that reproduce solely by females are pivotal for understanding the evolution and diversity of reproductive strategies. Rare males, often resulting from developmental errors, including chromosomal abnormalities, offer valuable insights into reproductive reversibility, although their rarity limits data on morphology, behavior, and fertility. Stick insects (Phasmatodea), with numerous parthenogenetic species, are key taxa for studying these phenomena; however, detailed analyses of rare males remain scarce. In this study, we investigated the spontaneous appearance of male and sexual mosaics within a captive colony of Neohirasea japonica, a widespread stick insect in Japan, where males are typically absent. In total, three individuals exhibiting male characteristics (penis and non-oviposition) were observed during the 8-year rearing. One displayed a typical male abdominal clasper and exhibited mating behavior with conspecific females, with morphological comparisons strongly suggesting that it was an N. japonica male. The other two individuals lacked mating behavior and were identified as sexual mosaics based on their external morphology and the presence of female reproductive systems upon dissection. This study provides foundational morphological and anatomical data on male, female, and sexually mosaic individuals in N. japonica. It also includes quantitative comparisons of key traits, such as the antenna-to-body length ratio, which is 0.78 in males and ranges from 0.52 to 0.53 in females. These findings establish valuable criteria for future identification of rare males and sexual mosaics in this species, ultimately contributing to our understanding of sexual trait degeneration in obligate parthenogenetic lineages.

To mitigate the impact of clear-cutting, the use of strip-cutting has increased in Japan. Strip-cutting creates uncut strips and extends forest edges compared to clear-cutting. To evaluate the impacts of strip-cutting on insect diversity, we captured carabid beetles using pitfall traps with or without fish meat bait in a conifer plantation that had undergone partial harvesting through 40-m-wide strip-cuttings and 60–120-m-wide clear-cuttings immediately before the study. The presence of bait had a negligible effect on carabid beetles. Species richness and Simpson's diversity index (1/D) were significantly higher in strip-cut areas than in clear-cut areas due to the increased presence of newly colonizing open-land species in the strip-cuts. Beetle assemblages were similar, with no significant differences observed between uncut forests and uncut strips. Species richness and diversity index were significantly higher at forest edges than in uncut areas, attributed to the presence of open-land species and the reduced abundance of the dominant forest species, Synuchus cycloderus, at forest edges. The diversity index was also significantly higher at forest edges than in harvested areas due to the presence of forest species and the low abundances of open-land species at forest edges. These findings suggest that strip-cutting is a more favorable harvesting method than clear-cutting to mitigate the impact on carabid diversity. Harpalus tridens, Harpalus jureceki, and Dolichus halensis exhibited significant positive relationships with understory cover degree in logged areas, whereas Colpodes buchanani showed a negative relationship. Carabus japonicus was abundant in both uncut areas and forest edges.

Reproductive interference has been reported in many organisms and has been observed in all aspects of the reproductive process. In some organisms, heterospecific females are preferred due to their larger body size. However, no studies have conducted mate choice experiments involving manipulation of female body size in species with smaller females than males. This study examined differential responses of males to female body size to determine the direction of reproductive interference in the butterflies Pieris melete and Pieris napi (Pieridae) by investigating whether female body size affects courtship partner recognition. In individuals of normal body size, both larger P. melete males and smaller P. napi males courted larger P. melete females with high frequency. However, when body size was manipulated by regulating temperatures during larval growth, smaller P. melete males courted smaller P. melete females, whereas larger P. napi males courted larger P. napi females. These results imply that an interspecies difference in the effect of female body size on courtship partner recognition caused reproductive interference between P. melete and P. napi.

The phytophagous ladybird beetle Henosepilachna niponica (Lewis) (Coleoptera: Coccinellidae) depends basically on thistles (Cirsium spp., Asteraceae) as its host plants. However, many previous studies have not identified the host plants (thistles, Cirsium spp.) of H. niponica, at the species level, and its host plants have often only been recorded as “thistles” or “Cirsium spp.” Furthermore, a few studies in which host thistle species have been identified appeared as small articles in Japanese language, reporting information regarding a particular site. Host thistle species across the distribution range of H. niponica have not yet been summarized, and only a few studies have elucidated the host plants of H. niponica at the regional level with the exact identification of the thistle species. In this study, we conducted a literature survey to integrate the scattered information on the host plants of H. niponica. In addition, we conducted field investigations for determining host-use patterns by H. niponica at 78 sites in the Tohoku district, northern Honshu, Japan, where information is relatively limited. The results revealed that H. niponica utilizes at least 19 thistle species as host plants across its distribution range, of which 4 thistle species (C. alpicola, C. amplexifolium, C. nipponicum, and C. tonense) are regarded as the main hosts of H. niponica in the Tohoku district.

Watanabe K (2024) Taxonomic revision of the extant species of the Japanese Stephanidae (Hymenoptera), with discussion on distribution pattern and conservation importance. Entomological Science 27, e12588. DOI: 10.1111/ens.12588

An error was noted in the data for a paratype of “Parastephanellus ryukyuensis sp. nov.”

The original statement incorrectly stated: “1F, Ryukyu Isls., Iriomotejima Is., Okinawa Pref., Taketomi Town, Komi, 4.XI.2023, in light trap, T.Wachi leg. (RUM).”

This should read as: “1F, Ryukyu Isls., Iriomotejima Is., Okinawa Pref., Taketomi Town, Funaura, 4.XI.2023, in light trap, N.Wachi leg. (RUM).”

We apologize for this error.

Cantharidin is produced only by beetles of Meloidae and Oedemeridae and represents a rare resource for canthariphilous insects that ingest fluids and/or portions of living and even dead meloid and oedemerid beetles. Although the physiological mechanism is unknown, these canthariphilous insects must have developed a superior ability to search for this rare resource in their habitats. They would be able to access cantharidin even in minute amounts. In this study, we found that canthariphilous insects are attracted to traces of cantharidin that remain in bird droppings after the birds have consumed meloid or oedemerid beetles. We succeeded in reproducing this phenomenon in the field by experimentally using quail droppings after giving meloid or oedemerid beetles. Thus, cantharidin was cycled from bird droppings to canthariphilous insects after being dispersed by birds widely and vertically in the cantharidin world consisting of cantharidin-producing insects and other interacting members via cantharidin.