Wing dimorphism in three carabid species living in the grasslands of Mt. Omuro, Shizuoka, Japan

Abstract

A 3 y study on the wing polymorphism of carabid beetles living in various habitats was conducted in Ito, Shizuoka, Japan. The survey covered grasslands, copses and farmlands. Seven species were grassland specialists, four were woodland or copse specialists, one was found only in fallow paddies and six species were identified as generalists being caught irrespective of the kind of habitat. Wing dimorphism was found in Hemicarabus tuberculosus (Dejean et Boisduval), Cymindis daimio Bates and Pterostichus samurai (Lutshnik), all of which were grassland inhabitants. Macropterous forms of H. tuberculosus were found at a low proportion of 0.022 in the population, giving an estimate of 0.15 for the frequency of a presumed recessive allele determining macroptery. There was a tendency for macropterous males to be larger in body size compared with brachypterous ones. Three and one macropterous specimens were found in the 39 and 35 sampled specimens of C. daimio and P. samurai, respectively. The three dimorphic species were found mainly in volcanic grassland, which is burned every February. It was suggested that they are the inhabitants of unstable harsh habitats.