Mitsuhiro Iwasa

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 control at 14 d after treatment. However, emergence rates of L. minutus were significantly reduced in dung from treated cattle for up to 14 d after treatment in both laboratory and field experiments. In a field experiment using emergence traps, numbers of flies emerged were 10,494 (18 families) in dung from untreated control cattle and 9,348 (17 families) in dung from treated cattle. Emergence of Paregle cinerella (Fallén), Neomyia cornicina (Fabricius), Ravinia striata (Fabricius), Sepsis latiforceps Duda, Sepsis duplicata Haliday, Sphaeroceridae spp., and Empididae spp. was reduced severely in dung from treated cattle. Conversely, numbers of Ceratopogonidae and Psychodidae increased in dung from treated cattle. Total dry weights of flies emerged from 48 dung pats in field experiments was 5,849.7 mg in dung from control cattle and 1,268.2 mg in dung from treated cattle, showing a 79.3% reduction in treated dung.

mtDNA variation in Vietnamese pigs, with particular emphasis on the genetic relationship between wild boars from Vietnam and the Ryukyu Islands

ABSTRACT To examine the genetic origin of Ryukyu wild boar, we sequenced mitochondrial DNA (mtDNA: 574-bp) from Vietnamese wild boar and Vietnamese indigenous domestic pigs and compared these sequences with the mtDNA of Ryukyu wild boar by phylogenetic analysis. Numerous Vietnamese wild boars were genetically related to Ryukyu wild boar, suggesting that descendants of the ancestors of Ryukyu wild boar still inhabit Vietnam. The mtDNA sequences of Vietnamese indigenous domestic pigs are extremely diverse and are thought to have contributed to the diversity of mtDNA among East Asian domestic pigs.

Effects of the Activity of Coprophagous Insects on Greenhouse Gas Emissions from Cattle Dung Pats and Changes in Amounts of Nitrogen, Carbon, and Energy

ABSTRACT Effects of coprophagous insects on greenhouse gas emissions from cattle dung pats were investigated during the initial stage in the decomposition of dung, with accompanying changes in nitrogen, carbon, and energy content. We set up three treatments with adults of Caccobius jessoensis Harold (dung beetle) and larvae of the fly Neomyia cornicina (F.): 1) dung with dung beetles; 2) dung with fly larvae; and 3) dung without insects. In these treatments, the gas flux was measured from air flow exiting the glass containers connected with an in vitro continuous gas analysis system. Total gas fluxes from dung pats with fly larvae were lowest in carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O). The presence of dung beetles significantly increased CO2 flux from dung, but reduced CH4 flux compared with dung without insects. Fluxes of N2O from dung pats with dung beetles and without insects had distinct peaks at different times after the start of the experiment, while N2O from dung with fly larvae was emitted in extremely low levels throughout the experiment. Carbon (C) content in dung with beetles was significantly lower than that of untreated dung pats designated as fresh dung, whereas that of dung with fly larvae was higher than dung with beetles and without insects. Nitrogen (N) content was significantly lower in dung with fly larvae than the other treatments. Contents of C and N in fly pupae were 35.87 and 8.05%, respectively. During the larval growth of the fly, energy accumulated in the fly body was 2,830 J/g.

The calliphorid larvae parasitic on birds in Japan (Diptera: Calliphoridae)

ABSTRACT. The immature stages of Protocalliphora maruyamensis Kano et Shinonaga are newly described and the third instar larva of P.azurea (Fallén) is redescribed from specimens collected in Japan. The larval morphology of Protocalliphora is discussed. A key to the third instar larvae of Japanese bird‐parasitic blowflies is given.

Six new species of the genus Dicranosepsis Duda (Diptera, Sepsidae) from Vietnam, with a revised key to the species

The flies of the genus Dicranosepsis from Vietnam were investigated and classified taxonomically. Six new species (D. longa sp. nov., D. kurahashii sp. nov., D. monoseta sp. nov., D. sinuosa sp. nov., D. barbata sp. nov., and D. vietnamensis sp. nov.) are described and illustrated. Dicranosepsis is redefined and a revised key to the species is also provided.

Taxonomic and faunistic studies of the Sepsidae (Diptera) from Vietnam, with descriptions of six new species

A total of 52 species belonging to nine genera of the Sepsidae are reported from Vietnam. Of these, six species (Dicranosepsis splendifica sp. nov., D. trochanteris sp. nov., Mucha rectotibialis sp. nov., Perochaeta exilis sp. nov., Sepsis nigriminima sp. nov. and S. silvicola sp. nov.) are described as new to science. Eighteen species are newly recorded from Vietnam. Toxopoda pseudoviduata Ozerov, 2010 is synonymized with T. cavata Iwasa, 2008. The faunal composition of Vietnamese Sepsidae is divided into six groups based on distributional data and discussed. A key to the species of Vietnamese Sepsidae is also provided.

Carabid beetles (Coleoptera: Carabidae) in coniferous plantations in Hokkaido, Japan: effects of tree species and environmental factors

The distribution, species composition and abundance of carabid beetles in monospecific plantations of three different coniferous tree species (Japanese spruce, Sakhalin fir and larch) were investigated by baited pitfall traps in Hokkaido, Japan. In total, 16 150 carabid beetles consisting of 31 species in 13 genera were collected in 2011 and 2012. The most predominant species was Pterostichus thunbergii Morawitz, followed by Synuchus melantho (Bates) and Carabus opaculus (Putzeys). Average numbers of beetles per trap were significantly reduced in larch. Large‐sized Carabus species (C. arboreus arboreus Lewis and C. opaculus) were collected in large numbers in Japanese spruce. There was no significant difference in diversity and equitability among the three kinds of plantation. The ordination of redundancy analysis showed that medium‐sized forest generalists, Pterosticus subovatus (Motschulsky) and P. thunbergii, were highly associated with Japanese spruce and Sakhalin fir, and the forest specialist Synuchus nitidus (Motschulsky) was with Sakhalin fir. In contrast, in larch there was no such associated forest species, and some species of Carabus, Pterostichus and Synuchus were considerably reduced in number, suggesting that larch has unfavorable effects on some forest species. The most important environmental variables influencing carabid assemblages were soil moisture and foliage layer cover. Practices in forest management to minimize the effects of plantations on carabid assemblages are discussed.

The genus Phyllomyza Fallén (Diptera: Milichiidae) from Japan, with descriptions of four new species

The Japanese species of the genus Phyllomyza Fallén are revised. Four new species, Phyllomyza kanmiyai sp. nov., P. amamiensis sp. nov., P. proceripalpis sp. nov. and P. japonica sp. nov., are described and illustrated. P. securicornis Fallén is recorded from Japan for the first time. A key to the Japanese species of Phyllomyza is presented.

The Strongylophthalmyiidae (Diptera) of Papua New Guinea, with descriptions of five new species and a world checklist

Eight species of the Strongylophthalmyiidae are reported from Papua New Guinea. Of these, five species (Strongylophthalmyia gigantica sp. nov., S. papuana sp. nov., S. rubella sp. nov., S. sedlaceki sp. nov. and S. shatalkini sp. nov.) are described as new to science. Strongylophthalmyia puncticollis Frey is recorded for the first time from Papua New Guinea. Faunistic remarks, a key to the species of the Strongylophthalmyia in Papua New Guinea and a world checklist are provided.

Revisional notes on the genus Toxopoda Macquart (Diptera, Sepsidae) in the Oriental and Australasian regions

I herein revise the genus Toxopoda Macquart of the Oriental and Australasian regions. A total of 16 species is discussed. Six new species are described: T. cavata sp. nov., T. angulata sp. nov., T. elephantina sp. nov., T. zuskai sp. nov., T. malayana sp. nov., and T. ozerovi sp. nov. The species T. contracta (Walker), T. viduata (Thomson) and T. simplex Iwasa, which can be easily confused with other species, are correctly redescribed and illustrated. Distributional notes and a key to the species of the Oriental and Australasian regions are provided.