Gall-feeding habits in Lepidoptera of Japan. IV : Tortricid moths reared from two cecidomyiid fruit-galls collected in late autumn

Abstract

This study examined tortricids reared from two cecidomyiid fruit-galls collected in late autumn. 1) The fruit galls of a cecidomyiid on the herb Achyranthes japonica (Amaranthaceae) were sampled on 16 October and 20 November, and reared in the laboratory. The galls were fed on by the larvae of two tortricid species, Lobesia aelopa Meyrick and Adoxophyes dubia Yasuda and the attack rate was less than 5%. In addition, since the larvae of the gall midge had already matured on 16 October and most larvae had egressed from the galls by 20 November, the tortricids imposed little negative effect on the cecidomyiid larvae. 2) Adoxophyes dubia emerged from the fruit galls of a cecidomyiid, Asteralobia sp. on the liana Trachelospermum asiaticum (Apocynaceae). The larva of A. dubia bored into and fed on gall tissue and the gall was considerably damaged. However, most cecidomyiid larvae matured or had already exited the galls. In addition, the attack rate was 8.3% (N=12). These two tortricid species are facultative cecidophages that primarily utilize normal plant tissues rather than plant galls. The tortricid larvae may feed on gall tissues as an alternative food source due to a dearth of fresh leaves in late autumn.