Preliminary studies on the effect of solar heat on oviposition, development and adult mortality of the cowpea bruchid Callosobruchus maculatus (F.) in the Nigerian savanna

The effect of solarization on oviposition, adult mortality and emergence of the cowpea bruchid Callosobruchus maculatus (F.) was investigated in the Nigerian savanna during the hot season (March-May). Oviposition was significantly reduced as time of exposure to the sun increased, especially in bruchids that were exposed for 3 h, but adult mortality increased with increased exposure time. Adult emergence from eggs that were exposed to the sun 5 days after oviposition (DAV) began was significantly lower than from eggs that were exposed 10 or 15 DAV. Adult emergence was also significantly lower from eggs that were exposed to the sun for 3 h than from those that were exposed for only 1 h. (C) 1998 Academic Press.