Effect of seasonal variation in temperature and humidity on the development of Callosobruchus maculatus and the efficacy of neem seed oil applied for its management in the Nigerian Sudan savanna

Three levels of neem seed oil were applied to cowpeas in each of the three seasons, cold, hot and rainy, to protect against Callosobruchus maculatus infestation. In each season, egg laying was reduced, especially in the cold season. In each season, neem suppressed adult progeny development and the percentage of eggs that developed to adulthood, the biggest effect being in the hot season. Neem prolonged the developmental period of C. maculatus in each season and developmental period increased with increasing dosage. Copyright © 2006 John Wiley & Sons, Ltd