A HISTOLOGICAL STUDY OF THE EFFECT OF FEEDING BY SMICRONYX SPP. (COLEOPTERA, CURCULIONIDAE) LARVAE ON SEED PRODUCTION BY STRIGA-HERMONTHICA(SCROPHULARIACEAE)

Experiments were conducted in Burkina Faso to determine the effect of feeding by Smicronyx spp. (Coleoptera: Curculionidae) larvae on the de velopment of fruit capsule and seed production in Striga hermonthica ( Scrophulariaceae). In treated plots Smi-cronyx adults were released in the cages while in untreated plots (= control) no Smicronyx were rele ased. The Striga capsules were collected, fixed, and prepared for hist ological examination. Uninfested Striga capsules developed normally. I n infested capsules, three types of galls were distinguished: they ref lected the development of capsule and the seeds. There was a synchrony between seed development and larval development in the same capsule. In most instances, one egg or larva was found per gall. Smicronyx larv ae completely destroyed Striga seeds in the developing capsule by two mechanisms: (1) by directly eating most of the seeds and (2) by eating the placenta that normally feed the seeds. (C) 1998 Academic Press.