Flight muscles of three pairs of flying and flightless beetles are examined by micro focus X-ray CT (SHIMADZU inspeXio SMX-100CT, or inspeXio SMX-225CT FPD HR). The flight muscles were completely atrophied in flightless forms of Phelotrupes (Eogeotrupes) laevistriatus (Geotrupidae) and Prosopocoilus hachijoensis (Lucanidae). On the other hand, they were not atrophied at all in the flightless strain of Harmonia axyridis (Coccinellidae), which was artificially produced for the purpose of biological control of harmful aphids in greenhouse.
Rosalia batesi Harold (Cerambycidae: Cerambycinae: Rosaliini) is associated with dead wood of many hardwood species in Japan mainland. Larvae have been observed to bore into heartwood, the least nitrogen-rich biomass. Little is known about its precise bionomics, however. In the present study, its larval boring habit was investigated together with another polyphagous dead-wood-boring cerambycine, Chlorophorus quiquefasciatus (Laporte & Gory) (Clytini) for comparison. Observations were carried out using boles of Pasania edulis (Makino) Nakai (Fagaceae) as their boring substratum. Larvae were regularly sampled to record the body weight, frass weight, larval tunnel volume, and C and N contents of larval body, frass and wood. The observations and measurements revealed no significant differences in mid-instar larvae for boring position within the wood substratum, the total length of the larval tunnels, and some other ecological factors between R. batesi and C. quinquefasciatus. On the contrary, R. batesi mature larva alone exhibited quite a different result from the others in the total length of tunnels, frass quantity, boring position, etc., suggesting quite different boring strategies of R. batesi larvae when matured. Rosalia batesi larva thus is thought to have a strategy, while young, of boring cambial and sapwood regions of the bole, obtaining more nutritious wood tissues as food, setting more importance on food quality than quantity, and then to have a strategy, when grown-up, of boring inner portion including heartwood, obtaining less nutritious tissues, setting more importance on food quantity than quality, with the latter situation likely involving less conspecific and/or heterospecific competitions and less hazzard of natural enemies.
An adult of Anthracophora rusticola (Burmeister, 1842) (Coleoptera: Scarabaeidae) was detected in the gut of a nestling Japanese crested ibis, Nipponia nippon (Temminck, 1835) which was once extinct in the wild in Japan and was subsequently reintroduced to Sado Island, northern Japan. To date, larvae and/or pupal chamber of A. rusticola have been collected from the nests of various bird species. This is the first study to report the possible predation of an adult A. rusticola by a nestling bird, N. nippon and the possible invasion of A. rusticola into the nests of these birds.
An overview of the families of Chrysidoidea distributed in Japan is given. As a common problem for each family, it is difficult to match males and females because of their sexual dimorphism and often their rareness. Due to changes in our lifestyle and land use, the abundance of some taxa has reduced compared to the past. On the other hand, several taxa previously seldom reported, like Embolemus, have been found one after another. The knowledge of the fauna of Japan was greatly improved especially for major groups such as Bethylidae in recent years.