TWO BILATERAL GYNANDROMORPHS IN THE CALYPTRATAE (DIPTERA): HYDROTAEA METEORICA (MUSCIDAE) AND SIPHONA HOKKAIDENSIS (TACHINIDAE)

Abstract

AbstractTwo bilateral gynandromorphs, specimens of Hydrotaea meteorica (Linn.) (Muscidae) and Siphona hokkaidensis Mesnil (Tachinidae), are described and illustrated. Circumversion of male genital parts is thought to have been prevented by adjacent female genital elements. Study of essentially unrotated male genital halves of these specimens suggests that asymmetry of male sternite 6 in schizophorans results from asymmetrical development (as advocated by Emmert (1972) and Griffiths (1972)) and not as a consequence of slight rotation during circumversion (as advocated by Crampton (1942) and McAlpine (1981)). From study of genital fusion of male and female sclerites across midline, it is further suggested that sternite 6 + 7 in the above species is derived primarily from sternite 6, not from sternites 6 plus 7 as described in Calliphora vicina R.D. by Emmert (1972).