Seasonal fluctuations in the population of Aleurodicus dispersus Russell (Homoptera: Aleyrodidae) on cassava plants in Benin City, Nigeria

Populations of the spiraling whitefly, Aleurodicus dispersus Russell (Homoptera: Aleyrodidae), were monitored on cassava plants in five sites in Benin City, Nigeria from February, 1999 to January, 2001 (24 months). The study revealed higher abundance of the whitefly on the mature and old leaves than the young ones. Since the distribution followed the same trend on all the sites, analysis of variance test on the data showed that the spatial distribution of whiteflies was not significantly different (P<0.05) from each other at P = 0.05 level. Periods of high population of A. dispersus coincided with the dry seasons suggesting that the whiteflies are dry season pests. There was a negative correlation between A. dispersus populations and rainfall ( r = 0.48) at 0.05 level.