Insects In Japan Research Articles

Discovery of a new population of the endangered giant water bug Kirkaldyia deyrolli (Heteroptera: Belostomatidae) in Kyushu and evaluation of their genetic structure

AbstractThe giant water bug Kirkaldyia deyrolli is one of the most well‐known endangered aquatic insects in Japan. The population of this species in Kyushu, one of the four major islands of the Japanese Archipelago, is extremely limited. In the present study, we identified a new population of K. deyrolli and undertook population genetic structure analyses based on genome‐wide nuclear DNA single nucleotide polymorphisms (SNPs). We collected samples using a nonlethal sampling method and obtained 59,279 SNPs. The results of our study confirm that sufficient SNP data for population genetic structure analysis can be obtained through nonlethal sampling. We determined that the newly identified population is genetically differentiated from a previously identified population on Kyushu. Therefore, this population is considered highly important for the conservation of K. deyrolli in Kyushu.

カイコ（チョウ目：カイコガ科），コバネイナゴ（バッタ目：バッタ科）およびモンクロシャチホコ（チョウ目：シャチホコガ科）の水溶性抗酸化能

To evaluate the dietary antioxidant content of insects, we analyzed the hydrophilic oxygen radical absorbance capacity（H-ORAC） of silkworms（Bombyx mori Linnaeus）, and rice grasshoppers（Oxya yezoensis Shiraki）, which have been used as edible insects in Japan for many years, and Japanese buff-tip moths, Phalera flavescens（Bremer et Grey）, which feed on cherry blossom tree leaves. Among these three insects, the H-ORAC value was highest（7455±185 µmol Trolox eq./100 g FW）in O. yezoensis adults, followed by B. mori pupae（4417.5±270.1）, B. mori larvae（4280±189.1）, and P. flavescens larvae（4112.5±409.4）. The H-ORAC of all three insect species were more than twice those of most fresh vegetables, suggesting high antioxidant potential.

Wickerhamiella bidentis sp. nov., a novel yeast species isolated from flowers and insects in Japan.

Two strains were isolated from flowers and insects in Japan, namely NBRC 115686T and NBRC 115687, respectively. Based on sequence analysis of the D1/D2 domain of the 26S large subunit (LSU) rRNA gene and the internal transcribed spacer (ITS) region and physiological characteristics, these strains were found to represent a novel yeast species of the genus Wickerhamiella. Considering pairwise sequence similarity, NBRC 115686T and NBRC 115687 differ from the type strain of the most closely related species, Wickerhamiella galacta NRRL Y-17645T, by 65-66 nucleotide substitutions with 12 gaps (11.65-11.83 %) in the D1/D2 domain of the LSU rRNA gene. The novel species differ from the closely related Wickerhamiella species in some physiological characteristics. For example, compared with Wickerhamiella galacta JCM 8257T, NBRC 115686T and NBRC 115687 assimilated d-galactose, and could grow at 35 and 37 °C. Hence, the name Wickerhamiella bidentis sp. nov. is proposed to accommodate this species in the genus Wickerhamiella. The holotype is NBRC 115686T (ex-type strain JCM 35540=CBS 18008).

Reviving the consumption of insects in Japan: a promising case of hebo (Vespula spp., wasps) by high school club activities

For people who hunt and eat hebo (Vespula spp., wasps) it is more about culture than it is about food production or environmental sustainability in mountainous central Japan. Individuals who currently semi-cultivate hebo do not intend to industrialize hebo semi-cultivation. Semi-cultivation of hebo is a seasonal activity and it is a hobby for them. This paper focuses on the declining number of wasp hunters. The number declined because younger generations did not take up the hobby or moved to urban areas in search of jobs. Hebo hunters thus consisted of seniors only. The number further declined as those who reached old age were no longer able to practice hebo hunting. Very recently, initiated a promising new development at Ena Agricultural High School. The support to the Hebo Club initiative was quickly expanded and now covers the members belonging to the Japan Vespula Association, and academics involved in edible insect research. We present an overview of the efforts of hebo hunters to maintain and promote the use of Vespula spp. as food and we describe the Hebo Club, a promising recent initiative spearheaded by the students of Ena Agricultural High School. The information was collected between fiscal 2015 and 2017 (namely from September 2015 to March 2018) by participant observation and semi-structured interviews with hebo hunters collaborating with the Hebo Club activities. The Hebo Club uses a hands-on approach: students gain knowledge on edible wasps and their semi-cultivation by actively engaging in the semi-cultivation of the wasps. The club thus teaches the students about resource use by engaging in resource use. The students are taught by experienced wasp hunters how to find, collect, house, and raise hebo. The Hebo Club’s colonies are housed in a shed in the school research forest. By cooperating with the members belonging to various Hebo Associations of south-eastern Gifu and northern Aichi, the students experience the variation in employed techniques and equipment, and make observations of hebo biology and ecology in different environments. Other than the hebo season, the club practice develops their idea for local development and applying it to tourism according to the evaluation of their activities. The successful beginning of the Hebo Club, a well-organized cultural initiative spearheaded by youngsters who are backed by seniors, is indicative of how people caring about hebo culture in central mountainous Japan maintains and preserves its culture and identity.

A novel approach using microsporidia to estimate the flight route of the common cutworm, Spodoptera litura (Lepidoptera: Noctuidae)

Microsporidia are unique fungi that exist as obligate intracellular parasites. Approximately 40% of the known microsporidian strains infect various insects. Due to their high host specificity, microsporidia have potential use as powerful biological pesticides. Here, we analyzed microsporidian strains isolated from the common cutworm, Spodoptera litura Fabricius (Lepidoptera: Noctuidae) of Japan and Taiwan, which is considered a pest insect. Two experiments were performed: a comparison of spore size and a phylogenetic analysis using small subunit ribosomal RNA gene sequencing. We then estimated the flight routes of S. litura by using the phylogenetic relationships of the isolated microsporidian strains as a marker. An analysis of spore size indicated that the test strains comprised three groups: Pleistophora, Nosema or Vairimorpha, and Trachipleistophora or Vavraia. The results of the phylogenetic analysis suggested a classification into five genera, including Vavraia. The genus Vavraia was first detected from lepidopteran insects in Japan. We estimated the sources and flight routes of S. litura using phylogenetic data for the genera Nosema and Trachipleistophora. In this study, we used microsporidia as a novel marker to estimate sources and flight routes of S. litura from Ogasawara and Southern China to mainland Japan, demonstrating the usefulness of this approach.

Molecular phylogeny and diversification timing of the Nemouridae family (Insecta, Plecoptera) in the Japanese Archipelago.

The generation of the high species diversity of insects in Japan was profoundly influenced by the formation of the Japanese Archipelago. We explored the species diversification and biogeographical history of the Nemouridae Billberg, 1820 family in the Japanese Archipelago using mitochondrial DNA and nuclear DNA markers. We collected 49 species among four genera: Indonemoura Baumann, 1975; Protonemura Kempny, 1898; Amphinemura, Ris 1902 and Nemoura Latreille, 1796 in Japan, China, South Korea and North America. We estimated their divergence times—based on three molecular clock node calibrations—using Bayesian phylogeography approaches. Our results suggested that Japanese Archipelago formation events resulted in diversification events in the middle of the Cretaceous (<120 Ma), speciation in the Paleogene (<50 Ma) and intra-species diversification segregated into eastern and western Japan of the Fossa Magna region at late Neogene (20 Ma). The Indonemoura samples were genetically separated into two clades—that of Mainland China and that of Japan. The Japanese clade clustered with the Nemouridae species from North America, suggesting the possibility of a colonisation event prior to the formation of the Japanese Archipelago. We believe that our results enhanced the understanding both of the origin of the species and of local species distribution in the Japanese Archipelago.

Species diversity of the entomopathogenic fungi Metarhizium anisopliae and M. flavoviride species complexes isolated from insects in Japan

Phylogenetic analyses of insect-derived isolates of the Metarhizium anisopliae and M. flavoviride species complexes in Japan were conducted to reveal their species diversity. Fifty-seven isolates were identified as nine species, including one species first reported for Japan. Metarhizium pingshaense was the most frequently isolated species from this genus, and the 29 isolates of M. pingshaense came from six orders and 14 families of insects. New host–pathogen associations were found for two species with relatively narrow host ranges: Hymenoptera-M. pemphigi, Orthoptera- and Phasmatodea-M. majus.

Species diversity of insects in Japan: Their origins and diversification processes

AbstractJapan is considered a global hot spot of biodiversity. With regard to species diversity, insects are no exception. To date, more than 32,000 insect species have been identified in Japan, while around 100,000 species of insects are estimated to inhabit this country. In this paper, we outline background factors having contributed to diversification of Japanese insects. Of course, the high degree of Japanese insect diversity is the result of many complex factors. In addition to the humid Asian monsoon climate and the extensive latitudinal gradient of habitats, the extremely complex geological history has contributed as an important factor to generate and maintain the high species diversity and endemism. In particular, the independent origins of northeastern and southwestern Japan from the Eurasian continent have greatly contributed to the diverse composition of Japanese insect fauna. To highlight the importance of this process, we introduce some case studies and previously published papers focusing on several insect groups with low dispersal ability. Those cases indicate that the geological history of Japan has played an important role in the differentiation of Japanese insect species. Besides such geological factors, climatic and ecological factors in combination have contributed to the formation of Japanese insect fauna in complicated ways and produced its particularly high degree of biodiversity. The knowledge compiled here will provide useful information for future studies aiming to understand more deeply the processes of speciation and faunal formation of Japanese insects.

Rediscovery of Celes akitanus (Orthoptera: Acrididae) from semi‐natural grasslands in Japan

AbstractCeles akitanus was rediscovered in semi‐natural grasslands in Japan. This species is one of the most endangered insects in Japan; most local populations were thought to be extinct. Reliable records of this rare species had been obtained only from Yamagata, Niigata, Tokyo and Nagano Prefectures. We compared the morphology of the holotype of Oedipoda akitana (=C. akitanus) and newly collected specimens and found that they matched with each other. The species was redescribed based on the holotype and new specimens. A molecular phylogenetic analysis involving other acridid species indicated that our samples were practically identical to C. akitanus from China. We conclude that the specimens we collected are C. akitanus, which has been rediscovered in Japan after about 30 years. Because the discovered populations were restricted to narrow and scattered areas, conservation of these populations should be a high priority. Population monitoring and habitat assessment are required. Because C. akitanus and many other endangered species are found in the grassland areas, these habitats should be protected and maintained.

大分県で採集したオンシツコナジラミのアセタミプリド剤に対する感受性低下

The greenhouse whitefly, Trialeurodes vaporariorum (Westwood) is one of the most devastating insects in Japan and has become a major pest of strawberry and tomato crops in the mountainous regions of Oita Prefecture. Seven populations collected from strawberry and tomato fields were tested for toxicity to 13 insecticides (acetamiprid, imidacloprid, clothianidin, dinotefuran, thiacloprid, nitenpyram, emamectin benzoate, chlorfenapyr, spinosad, tolfenpyrad, pymetrozine, pyridaben, and flonicamid), using the leaf-dipping method. Acetamiprid showed reduced mortality to both adults (mortality, 24.1 to 55.1%; LC50, 102.3 to 483.3 ppm) and larvae (mortality, 53.8% and 57.4%;LC50, 97.0 and 85.9 ppm). However, the other 12 insecticides showed high mortality (72.8 to 100%). These results provide the first evidence of a decline in susceptibility to acetamiprid in both adults and larvae of T. vaporariorum.

Comparison of egg-hatching rate, survival rate and development time of the immature stage between B- and Q-biotypes of Bemisia tabaci (Gennadius) (Homoptera: Aleyrodidae) on various agricultural crops

Bemisia tabaci (Gennadius) (Homoptera: Aleyrodidae) B- and Q-biotypes are exotic insects in Japan and are consequently regarded as insect pests in agricultural fields. Using B- and Q-biotypes, we investigated the hatching rate, survival rate during the larval stage and the total development period from egg to adult. Whiteflies were allowed to lay eggs on several host plants: cabbage, Brassica oleracea var. capitata; cucumber, Cucumis sativus L.; tomato, Solanum lycopersicum L.; eggplant, Solanum melongena L.; bell pepper, Capsicum annuum cv. grossum; and five cultivars of kidney bean, Phaseolus vulgaris (cvs. Kentucky101, Nagauzura, Morocco, Satsukimidori and Honkintoki), and the effects on the above traits were evaluated. Clear differences between the two biotypes were detected. A particularly important difference was that the B-biotype successfully developed to adults on only one of five cultivars of kidney bean, whereas the Q-biotype was able to utilize all the test plants as hosts regardless of the cultivar. This finding suggests that the determination of host plants in B. tabaci is greatly influenced by not only plant species but also by cultivar. In addition, there is a high possibility that the Q-biotype has the ability to adapt to a wider range of plant species and cultivars compared with the B-biotype.

B08 牛用駆虫剤モキシデクチンの糞分解性昆虫に及ぼす影響(一般講演,演題要旨,第58回日本衛生動物学会大会)

B08 牛用駆虫剤モキシデクチンの糞分解性昆虫に及ぼす影響(一般講演,演題要旨,第58回日本衛生動物学会大会)

Nontarget Effects of Ivermectin on Coprophagous Insects in Japan

Abstract Effects of the antiparasitic drug ivermectin on the dung-breeding flies and beetles Liatongus minutus (Motschulsky) were studied in laboratory and field experiments in Hokkaido, Japan. Ivermectin was detected in dung from 1 to 21 d after treatment, with a peak at the first day after treatment in two pour-on administrations (500 μg/kg). Laboratory bioassays were performed on the flies Musca bezzii Patton and Cragg and Scatophaga stercoraria L. and on the beetle Liatongus minutus. Dung from treated cattle inhibited larval development of M. bezzii from 1 to 14 d and pupation rate was reduced 21 d after treatment. In S. stercoraria, pupation and emergence rates were reduced for up to 14 and 28 d, respectively. In laboratory experiments of the dung beetle L. minutus, no significant difference was found in numbers of brood balls constructed per female between dung from treated and control cattle, whereas in field experiments, numbers of brood balls recovered in treatment were more abundant than that of...

Outbreaks of forest defoliating insects in Japan, 1950-2000.

In Japan, several forest-defoliating insects reach outbreak levels and cause serious defoliation. Stand mortality sometimes occurs after severe defoliation. However, in general, tree mortality caused by insect defoliation is low because of the prevailing moist climate in Japan. Evergreen conifers are more susceptible to tree mortality as a result of insect defoliation whereas deciduous broad-leaved trees are seldom killed. Insect defoliation occurs more frequently in man-made environments such as among shade trees, orchards, and plantations than in natural habitats. Outbreaks of some defoliators tend to occur in stands of a particular age: e.g. outbreaks of the pine caterpillar, Dendrolimus spectabilis Butler (Lepidoptera: Lasiocampidae) occur more frequently in young pine plantations. In contrast, defoliation caused by outbreaks of lepidopterous and hymenopterous pests in larch plantations is more frequent with stand maturation. There is a relationship between outbreaks of some defoliators and altitude above sea level. Most outbreaks of forest defoliators were terminated by insect pathogens that operated in a density-dependent fashion. Since the 1970s, Japan has been prosperous and can afford to buy timber from abroad. More recently, there has been an increasing demand for timber in Japan, that coincides with a huge demand internationally, so that the country will need to produce more timber locally in the future. The increasing pressure on the forestry industry to meet this demand will require more sophisticated methods of pest control coupled with more sustainable methods of silviculture.

Allergy to insects in Japan: III. High frequency of IgE antibody responses to insects (moth, butterfly, caddis fly, and chironomid) in patients with bronchial asthma and immunochemical quantitation of the insect-related airborne particles smaller than 10 μm in diameter

After recognizing that moth, butterfly, caddis fly, and chironomid were the insects predominantly found in our environment, reaginic sensitivities to these insects in patients with asthma were investigated with extracts of silkworm wing for the detection of moth and/or butterfly allergy, caddis fly wing for caddis fly allergy, and chironomid whole body for chironomid allergy. At least 50% of 56 randomly selected patients with asthma had positive intracutaneous reactions to these insect extracts, and at least 80% of the skin reaction positive patients had specific IgE antibodies. An immunochemical assay of these insect-related aeroallergens in the dust collected 18.6 m above ground revealed the presence in the air of insect-related particles <10 μm in diameter with two peaks a year, one in the spring (silkworm wing, 3.18 ng protein equivalent to that of the crude extract per cubic meter of air; caddis fly wing, 3.08 ng/m 3; and chironomid whole body, 5.21 ng/m 3) and one in the autumn (silkworm wing, 8.24 ng/m 3; caddis fly wing, 4.74 ng/m 3; and chironomid whole body, 18.19 ng/m 3). Although we have no idea whether or not such peak values are enough to cause asthmatic symptoms, seasonal fluctuations of specific IgE antibodies to these insects appeared to be similar to those of atmospheric insect allergens measured by this method. These findings suggest that insects are widespread and common inhalant allergens.

Allergy to insects in Japan: II. The reaginic sensitivity to silkworm moth in patients with bronchial asthma

The reaginic sensitivity to extract of silkworm moth wing (silkworm wing) and to that of silkworm moth body (silkworm body) was studied in 50 randomly selected asthmatic patients. Although none of the patients had occupational exposure to silkworm moth, 34 (68.0%) of these patients showed positive reaction to silkworm wing while 28 (56.0%) patients reacted positively to silkworm body following intracutaneous injection(s). Radioallergosorbent tests (RASTs) showed that 22 (44.0%) of 50 sera were positive to silkworm wing and 11 (22.0%) sera were positive to silkworm body, with less uptake of 125I-labeled anti-immunoglobulin E in silkworm body than in silkworm wing RASTs. This suggests that wing components are more common sensitizers than body components. A fairly high percentage of these 50 patients also showed reaginic sensitivity to the extracts of butterfly, moth, and mite. That is, 26 (52%), 22 (44%), and 32 (64%) of these 50 patients had butterfly-, moth-, and mite-specific IgE antibodies in their sera, respectively. The seasonal variations of silkworm wing-, butterfly-, moth-, and mite-specific IgE antibodies and mutual RAST inhibition tests revealed that IgE antibodies to silkworm wing, butterfly, and moth were identical but all differed from the antibody to mite. These data suggest that the extract of silkworm wing is useful for the detection of allergy to moth and butterfly and also provides a suitable allergen source of unlimited quantity and consistent quality. It was also shown that the allergy to Lepidoptera (moths and butterflies) in Japan is found as commonly as that to mite, but without cross-reactivity between them.

Dinorhynchus dybowskyi , 1 an Arboreal Predator of Forest Insects Including the Gypsy Moth, in Hokkaido, Japan, and Laboratory Rearing Success

In forests in Hokkaido, Japan, nymphs of the univoltine Dinorhynchus dybowskyi Jakovlev, an arboreal predator of forest insects in Japan and eastern Asia, developed in the presence of, and attacked, larvae, pupae, and adult gypsy moths, Lymantria dispar (L.). Oviposition, a double column of eggs laid in masses averaging 39.9 eggs, maximum 83, occurs Aug.–Oct. Eggs were found on smooth barked trees (44% Cornus controversa Hemsl. and 24% on Acer spp.) with avg trunk diam of 6.8 cm at an avg height of 2 m and were often positioned on the SW side of trees. Eggs overwintered and hatched in early June. Winter survival was high since 81.5% of eggs in 114 egg masses hatched; mortality was due to apparent infertility. One egg parasite was detected naturally, a damaged Telenomus sp. dead in a winter collected mass with holes from fall emergence. Oversized Anastatus japonicus Ashmead (Hymenoptera: Eupelmidae) emerged from some eggs reposited low on small trees, and Anastatus kashmirensis Mathur emerged from eggs accidentally exposed in quarantine. Phania vittata Meigen (Diptera: Tachinidae) maggots emerged from mature nymph or adult bugs. Birds occasionally damaged eggs during winter. Living material shipped to the USA was successfully reared for one generation. In early stage feeding tests, 1st-instar nymphs, though possibly “phytophagous,” readily molted to 2nd instar in the presence of only water or of several plant species tested. After the 1st molt, feeding requirements changed abruptly, lind they became obligate predators, occasionally cannibalistic, requiring an avg of 16.2 prey caterpillars for development. All known prey are tabulated and life stages are illustrated.

Allergy to insects in Japan: I. The reaginic sensitivity to moth and butterfly in patients with bronchial asthma

A high frequency of reaginic sensitivity to moth and butterfly extracts was shown in 66 randomly selected patients with bronchial asthma. Thirty-seven (56.1%) of these 66 patients showed positive intradermal reactions to 1:10,000 dilution of moth allergen and 34 patients (51.5%) had positive reactions to 1:10,000 butterfly allergen. These positive responses were as frequent as those to Candida or house dust which are recognized as the most commonly reactive allergens in Japan. Radioallergosorbent tests (RAST) showed that 20 of 66 sera were positive to moth and 22 sera were positive to butterfly, which indicates that about 113 of patients with bronchial asthma had specific IgE to moth and butterfly in the sera. Bronchial testing revealed that skin reaction-positive and RAST-positive patients were commonly provoked by specific allergen but skin reaction-negative and RAST-negative patients were not. These data suggest that moth and butterfly emanations could cause allergy-induced bronchial asthma in certain patients. Since moths are attracted readily to artificial lights and often fly into houses, these insects are especially suspect as important factors in extrinsic asthma.

Different infection response of silkworm larvae to the locality of cytoplasmic-polyhedrosis virus injection

Cytoplasmic polyhedrosis viruses (CPV) are common contaminants among the insect populations collected in the field or reared in the laboratory. This chapter discusses CPV with current updated results, mainly obtained in the laboratory, on the replication as well as on the biochemical and molecular biology of this group of viruses. The role of CPV as pathogens of beneficial insects in Japan contributed in the beginning to their recognition as important viruses among the Reoviridae. The demonstration of the role of CPV alone or combined with other pathogens and chemical products in the control of insect populations and their damage justifies their use as a component of integrated pest-control programs. Advances in molecular-biology studies and genetic engineering of the CPV, complemented by the development of excellent systems for the replication of these viruses, gave a new start to the study of the cytoplasmic polyhedrosis viruses.

Climatic Areas Potentially Vulnerable to Stored Product Insects in Japan

The relationship between the mean monthly normal temperatures at 116 geographical locations in Japan and the minimum temperatures below which development ceases was established theoretically for major species of stored product insects. In unheated premises monthly mean temperatures of 17°C or higher were considered minimum for the development o most injurious stored product insects including Callosobruchus chinensis, Sitophilus spp., Cadra cautella, and Plodia interpunctella, 20°C or higher for Tribolium spp., Oryzaephilus surinamensis, and 24°C or higher for Trogoderma granarium, Rhizopertha dominica, and Cryptolestes ferrugineus. From these relationships the number of months when storage premises have conditions favorable for the development of certain species or groups of species were calculated for various areas in Japan. Maps based on these evaluations show that Sitophilus and most other stored product insects can cause serious problems throughout Japan except in the central and northern part of Hokkaido. Rhizopertha dominica can attack stored food in Sikoku, Kyushu and the soluthern coastal areas of south-west Honsyu. But the severity of its infestation is likely to be minimised due to competition from Sitophilus spp. Triborium spp. and O. surinamensis are likely to occur in all parts of Japan except Hokkaido and most of north central Honsyu. Trogoderma granarium, because of its need for hot and dry conditions and pressure of inter-specific competition from Sitophilus spp. and R. dominica, was thought unlikely to be a serious pest of stored grain in most areas of Japan except in large warehouses along the coast of Seto Inland Sea, especially around Kobe and Kure.