Preliminary evidence for the existence of differential susceptibility to Megastes grandalis (Guen) infestation in West Indian sweet potato cultivars.
Megastes grandalis Gn. is an important pest of sweet potato in South America and Trinidad [cf. RAE/A 14, p 226] but has not yet been recorded from other islands in the West Indies. In studies in Trinidad in which the Pyralid was partially controlled by applications of methomyl and malathion, the percentages of plants infested 12-24 weeks after planting ranged from 0.20 according to cultivar. The severity of the damage caused also varied. The attacks had no significant effect on the yield of tubers; this is attributed to the compensatory development of extensive secondary phloem and corticular vascular bundles.