Abai, MR

6th International Congress of DipterologyKey Words: mating behavior, wing modification, Hercostomus,Dolichopodidae∗∗∗∗∗∗∗∗∗∗Findings of two new Mikiola species (Diptera:Cecidomyiidae) that induce leaf galls on Fagus crenata(Fagaceae) in Japan and their phylogenetic relationshipswith M. fagi in EuropeSato, S. & J. YukawaKyushu University, Hakozaki, Fukuoka 812-8581, JapanIn Japan, at least 26 sorts of midge gall have been known to occur on theleaves of Fagus crenata (Fagaceae). Because gall shape and galledposition are species-specific of gall midges in many cases, we haveconsidered that the 26 sorts of gall are induced by different gall midgespecies (Diptera: Cecidomyiidae). However, most of them have been leftunidentified due to difficulties in rearing adults from larvae that overwinterin cocoons or in fallen galls on the ground. Among the 26 sorts, we havenoted that two different sorts of acorn-shaped gall on F. crenata leaves aresimilar to that induced by Mikiola fagi on the leaves of Fagus sylvatica inEurope. Recently, we succeeded to rear adults of the gall midges from theacorn-shaped galls. Based on morphological features of mature andimmature stages as well as the gall shape, we considered that the gallmidges belong to the genus Mikiola, which has been represented by onlytwo species in the world: Mikiola fagi in Europe and Mikiola orientalisinducing leaf galls on Fagus sp. in Asia Minor. Morphological differencesbetween the Japanese gall midges obtained from the two different acornshapedgalls were relatively obscure, but partial sequences of thecytochrome oxidase subunit I (COI) gene of mtDNA indicated that they220