Population dynamics of thrips, whiteflies and their natural enemies on mustard (Brassica campestris L.) Crop in different localities of Sindh, Pakistan

Abstract

Present studies were conducted on population dynamics of sucking insect pests; thrips, Thrips tabaci and whitefly Bemesia tabaci, and their predator, Geocoris spp., on Mustard crop Brassica compestris L. Results showed that weekly mean population per leaf of thrips, whitefly and their predator, Geocoris varied with different dates and phenology of mustard localities. Initially, population of thrips and whitefly were very low (3.69±0.45, 1.00+0.25) in 3 rd week of December 2010, and highest recorded (100.62+0.51, 24.77+0.89) in 3 rd week of March, respectively. Correspondingly, predator Geocoris remained maximum (15.33+0.31) in 3 rd week of February and minimum (4.50+0.25) in 1 st week of January at Tando Allahyar. The present results demonstrated that mean population of thrips and whitefly at Tandojam fields was maximum (129.46±0.84, 40.85+0.90) in 3 rd week of March and minimum (4.92+0.55, 2.69+0.21) in 3 rd week of December, respectively. Predator’s Geocoris population was minimum (5.00+0.32) in 3 rd week of December at initial stages and reached at peak (10.50+0.31) in 3 rd week of March. Temperature and humidity varied during different dates and time, and played an important role in increasing thrips, whitefly and Geocoris population.