Full Text
(28 K)

Spatial Distribution Patterns of Two Cotton Bollworms, Pectinophora Gossypiella and Earias Insulana in Qaulubia Governorate, Egypt

Mohamed E. Foda


Dispersion indices, including (k) the negative binomial distribution, Green's coefficient of dispersion (Cx ), mean crowding (m* ), Lloyd's (Patchiness index) (m/m*) and variance mean ratio (v/m), were calculated for the populations of two cotton bollworm male moths, Pectinophora gossypiella and Earias insulana, using pheromone traps all-over 2 years (October 95 to Sept. 97) at kaha district, Qalubia Governorate. Comparison showed that: k, Cx and m/m* as well as slopes from regression, all indicated that under the conditions of this test (at densities tested), the populations of the two pests were random. The variance / mean ratio fluctuated considerably more than other indices examined, which, by comparison, appears less reliable than previously thought.

Reprinted from Proceedings of the 1998 Beltwide Cotton Conferences pp. 1230 - 1232
©National Cotton Council, Memphis TN

[Main TOC] | [TOC] | [TOC by Section] | [Search] | [Help]
Previous Page [Previous] [Next] Next Page
Document last modified Sunday, Dec 6 1998