author(s)
SC Verma, PL Sharma, RS Chandel and Sarswati Negi

abstract
Investigations were carried out during October 2017- March 2018 at the Experimental Farm of the Department of Entomology, Dr Y S Parmar University of Horticulture and Forestry, Nauni, Solan, Himachal Pradesh, India in order to study the spatial distribution of Myzus persicae and its parasitoid, Aphelinus asychis Walker in bell pepper under poly house conditions. One month old bell pepper seedlings cultivar California wonder were planted in the field in the month of October, 2017. In the present study 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 (σ²=5.2646X^1.335 for aphid and σ² = 2.7871 X^1.277 for parasitoid), Iwao’s patchiness regression and optimum number of samples (N_opt) required to achieve the desired precision were calculated for different densities. Green peach aphid, M. persicae appeared in the 47^th standard week (57.47aphids/ plant and 0.65 parasitoids / plant during 2017) and persisted upto 4^th standard week (2.79 aphids/ plant and 0.15parasitoids / plant during 2018 is ongoing) and followed a negative binomial distribution. Optimum number of samples (N_opt) required varied with mean density as well as precision level. The present study will be useful for developing a sampling plan of M. persicae and its parasitoids, A. asychis in bell pepper for its monitoring and management.