Spatio-temporal distribution of winged Aphis gossypii (Hemiptera: Aphididae) presences in cotton (Malvaceae) field

摘要

The spatio-temporal distribution of cotton plants, Gossypium hirsutum L., infested with Aphis gossypii (Glover) winged adults, was examined in 1982 in a plot located in Bangui, Central African Republic. Each cotton plant growing in the plot was examined visually for a short period of time to ascertain the presence or absence of A. gossypii and to construct weekly infestation maps. Tests of autocorrelation and dispersion were carried out at different spatial scales by means of Monte Carlo procedureson embedded counting grids. Edge effect tests were also carried out. The statistical analyses show significant overdispersion of the infested plants and positive spatial autocorrelation. Positive temporal autocorrelation and significant edge effect aredetected intermittently throughout the season.