Spatial distribution of Aphidius matricariae (Haliday) and Myzus persicae (Sulzer) in bell pepper under polyhouse conditions

The spatial distribution of Aphidius matricariae and Myzus persicae was studied in bell pepper under polyhouse conditions. In the present study, M. persicae and its parasitoid, A. matricariae populations followed negative binomial distribution throughout the season. The variance to mean ratio (σ2/X), mean crowding (X*), ratio of mean crowding to mean (X*/X), ‘k’ of negative binomial, Taylor’s power equation for M. persicae and A. matricariae were σ² = 6.97X1.531 (R2 = 0.931), and σ² = 4.29X1.282 (R2 = 0.90) during 2018-2019, respectively. Iwao’s patchiness regression was X* = 45.12 + 1.333X (R2 = 0.853), and X* = 5.406 + 1.195X (R2 = 0.767) during 2018-2019, respectively. Optimum number of samples required for the green peach aphid, M. persicae and A. matricariae were 261.1 and 474 at 20% precision level. The present study will be useful for developing a sampling plan of M. persicae and its parasitoid, A. matricariae in bell pepper for its monitoring and management.