Demographic Interactions between the Inquiline Midge Macrolabis mali (Diptera: Cecidomyiidae) and its Gall-inducer Host Dasineura mali (Diptera: Cecidomyiidae)

Abstract

The apple leaf curling midge, Dasineura mali (Kieffer 1904), damages apple trees when inducing leaf galls. Recently a new species, Macrolabis mali Anfora 2005, signalled from South Tyrol to South Western Germany, was described and hypothesized to be an inquiline of D mali. In this study, investigations of the biology of M mali and its interactions with D mali have been made both in laboratory and in field. The results indicate that M mali females lay eggs in young galls caused by their host and that M mali larvae act as inquilines. The inquiline population increases during the summer until the end of September. At this point, the inquiline population has become larger than that of the host, whose larvae fall back. Therefore, M mali contributes to reducing apple leaf curling midge populations.