Some biological characteristics of pupae of two species of lepidopterous maize stemborer laboratory reared for inherited sterility control programme in Ghana

Abstract

Studies were conducted on pupal development of two lepidopterous maize stemborers, Eldana saccharina Walker and Sesamia calamistis Hampson. Biological characteristics of differences in length, weight, adult emergence, and pupal longevity were determined, having fed larvae of the two species, one group on fresh maize stem cuttings (natural dieters) and the other group on artificial formulated diet (artificial dieters), respectively. Pupal length increased proportionally with increase in mean weight for both dieters. Generally, natural dieters showed heavier weights than artificial dieters for both species of stemborers. There was decrease in change of pupal weight with respect to increasing days of pupal development. Percentage of adult emergence was high for both natural and artificial dieters of E. saccharina (50%-100%) and S. calamistis (70%-100%), respectively. In E. saccharina, relatively smaller-sized pupae (9–12 mm) showed higher percentage of male emergence (50%-67%), while larger pupal sizes (> 12-16 mm) emerged as females (53%-100%) for both natural and artificial dieters. Similar trend of characteristics was also observed in S. calamistis. Mean pupal longevity for both natural and artificial dieters of E. saccharina ranged from 10 to 11 days and that of S. calamistis was between 10 and 13 days. The biological characteristics observed in this study have shown that laboratory-reared species were competitive and comparable with species in the wild.

JOURNAL OF THE GHANA SCIENCE ASSOCIATION Volume 2 No. 2 (2000) pp. 54-61