POPULATION DYNAMICS OF PREDATORY COCCINILIDS IN CEREAL CROPS OF DISTRICT FAISALABAD

Abstract

Pakistan’s population extremely relies on cereals for their daily food requirements. Cereal crops are vulnerable to many pest species particularly aphids. In the wake of economic well-being and food security these bio-weapons must be controlled. In that context biological control by predators is a sustainable management strategy to solve ecological problems with environmental concerns. This study was aimed to identify Coccinellids as potential predators of aphids and their spatio-temporal organization patterns in cereal crops that would help in developing biological control program in this area. A survey at large scale was conducted to assess the abundance of predatory Coccinellids in cereal crops with respect to seasonal rhythms in district Faisalabad. A total of eighteen Coccinellid predator species were identified representing fourteen, eleven and six species in wheat, maize and rice crops, respectively. The dominant Coccinellid species encountered was Coccinella septemptunctata. Coccinellid predator’s density was greater 80.6% in wheat than in maize 13.54% and rice 5.74% crops. Highest value of H'(1.6760) was estimated for maize and least for wheat (1.0585) crop. Evenness (E) was observed to be greater in rice 0.8068 cropland while highest value of dominance (D) 0.5989 was determined in wheat. Mean period of maximal diversity and abundance for Coccinellidae was early spring as maximum abundance 52.04% was recorded in February and March 2016 only. The data of these months together yielded 37.12% of Coccinellid abundance compared with rest of months. Species abundance decreased with higher rainfall, warmer temperature while increased with higher air moisture. Significant variations in richness and abundance among sites, crops and months are concordant. As these species occurred at high densities in the fields enough to reduce aphid damage in the cereal crops. Therefore, the spatial and temporal organization patterns ofCoccinellids, as revealed in this study might be helpful in developing the natural biological control strategy against pests for regulation of the cereal agro-ecosystem.