Some Notes on Maize Stemborers in Nigeria1

Emergence of moths of Busseola fusca Fuller and Sesamia calamistis Hampson was influenced by the onset of darkness. Most of these moths emerged at about 7 pm, nearly an hour after sunset, and continued until about 10 pm. Copulation appeared to induce female stemborer moths to oviposit readily, uniformly, and within a few days. Unmated moths laid fewer eggs, and these erratically. Copulation of unmated females after a period of up to 4 days after emergence did not significantly affect the fecundity of females. In both B. fusca and S. calamistis there was only a slight difference between the longevity of the unmated male and female moths. Mated moths, especially the females, had a shorter life span, probably because of activities involved in mating and oviposition.