A. B. O. Ogedegbe

An ecological survey of acridoid grasshoppers was conducted in the Niger Delta region of Nigeria from January to November 2001. A total of 34 taxa distributed in 3 families, 12 sub-families and 27 genera were encountered. The family Acrididae had the highest number of species (28), followed by pygomorphidae with 5 species. The family Tetrigidae was represented by only one species. Several species showed ecological plasticity and were found in all the locations while many others showed ecological restriction.

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.