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A model of temporal distribution of Aphis gossypii (Glover) (Hem., Aphididae) on cotton
Author(s) -
Celini L.,
Vaillant J.
Publication year - 2004
Publication title -
journal of applied entomology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.795
H-Index - 60
eISSN - 1439-0418
pISSN - 0931-2048
DOI - 10.1111/j.1439-0418.2004.00823.x
Subject(s) - aphis gossypii , biology , aphididae , overdispersion , negative binomial distribution , statistics , population , pest analysis , economic threshold , linear regression , gossypium hirsutum , aphid , regression analysis , population density , botany , horticulture , mathematics , homoptera , demography , poisson distribution , sociology
The spatio‐temporal distribution of Aphis gossypii (Glover) was studied for a 4‐year period in a plot of Gossypium hirsutum located in Bangui, Central African Republic. A study of the temporal evolution of the number of aphids by means of non‐linear regression indicated a rapid population increase during the first 8 weeks of cotton cultivation. The overdispersion of the aphids was found to be significant during most of the season. We tested three population dispersion models; Iwao's model and Taylor's power law describe the relationship between the mean m and variance σ 2 for the number of aphids, and the Nachman's model describes the functional dependence between m and the proportion p of non‐infested cotton plants. The results of these statistical tests indicate that only the Taylor's model was not rejected. The aphids’ aggregation increases with population density. The regression parameter confidence intervals for each of the 4 years of observation prove the stability of the Taylor's model. The model σ 2 = 45 m 1.3 is recommended when the environmental and cultural conditions are similar to those of our study.