MEASURING THE DISTRIBUTION OF PINK AND SPINY BOLLWORMS IN DIFFERENT GOVERNORATES IN EGYPT | ||
Egyptian Journal of Agricultural Research | ||
Article 10, Volume 78, Issue 3, September 2000, Pages 1091-1104 PDF (4.15 M) | ||
Document Type: Original Article | ||
DOI: 10.21608/ejar.2000.322669 | ||
Author | ||
MOHAMED A. ROMEILAH | ||
Plant Protection Research Institute, Agricultural Research Centre, Dokki, Giza, Egypt | ||
Abstract | ||
Dispersion indices, including (K) the negative binomial distribution, Green's coefficient of dispersion (CO mean crowding (m"), Lioyd's (Patchiness index (m/m*) and variance mean ratio (v/m), were calculated for the populations of two cotton bollworm moths, Pectinophora gossypiella and Earias insutana using light traps allover 2 years (January 1997 to December 1998) at five different Governorates, El-Minia, ElSharkia, Kafr Et-Sheikh, Demeate and El-Kalubia. Comparison showed that: K, Cx and Wm' 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 (v/m) ratio fluctuated considerably more than other indices examined, which by comparison, appears less reliable than previously thought. | ||
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