Population dynamics of Cacopsylla sp. (Hemiptera: Psylloidea: Psyllidae), pest insect of Prunus africana (Rosaceae), medicinal plant species in Cameroon

Abstract

Prunus africana is threatened in Cameroon by xylophagous and sap-sucking pest as Cacopsylla sp. This last causes deformations of the young leaves and buds and the plant end up losing all its leaves. Effective control of phytophagous pests requires a thorough understanding of their seasonal population dynamics. The objective of this work carried out on 150 young plants of P. africana in the nursery in Dschang, was to study the population dynamics of Cacopsylla sp. and the impact of climatic factors on the population. From January 2006 to December 2007, monthly collections of larvae, males and females of Cacopsylla sp. were carried out. The results showed, in 2006, three peaks (March, August and December) and two peaks in 2007 (March and August) with larvae. The fluctuation of males' population showed five peaks with two peaks in 2006 (March and December) and three peaks in 2007 (March, June and December) while in females' population, four peaks with two peaks in 2006 (March and December) and two peaks in 2007 (March and November). The annual numerical variation of Cacopsylla sp. individual is statistically correlated with variation of precipitations and the insolation. The precipitations have a negative effect on the numerical variation of males (r=-0.430, p<0.0360) and females (r=-0,434, p<0.0336) of Cacopsylla sp. The insolation has a positive effect on the numerical variation of males (r=0.732, p<0.0000002), females (r=0.653, p<0.000523) and the total individuals (r=0.601, p<0.00197) of Cacopsylla sp. With the larvae, the correlation was negative and non-significant. This work showed that March and December were better indicated to engage the fight against Cacopsylla sp. in Dschang.