PREDATOR-PREY RELATIONSHIP AMONG SELECTED SPECIES IN THE CROPLANDS OF CENTRAL PUNJAB, PAKISTAN

Predator-prey relationship is of great importance in the agro-ecosystems. insects being the largest group of arthropods have a major role in designing various management strategies against different crop pests. theoretically, these interactions influence the structure and dynamics of an agro-ecosystem and the present project is a good example of this .a mathematical model was proposed and analyzed to study the dynamics, of autonomous predator- prey model with a logistic abundance ratio. the major coleopteran predators; coccinella septempunctata, coccinella undecimpunctata, cheilomenes sexmaculata hippodamia variegata and calosoma maderae and important hemipteran prey/pests; schizaphis graminum, aphis maidis, macrosiphum miscanthi , aphis gossypii and diuraphis noxia were sampled from mixed crop agro-ecosystems of central punjab. the study was conducted to find the monthly abundance ratios of each predator species with all of the prey species in wheat, fodder and brassica crops. a graphed horizontal straight line was taken as constant predator-prey relationship. chi-square test was applied on the relative abundance of a predator with selected prey species. accordingly, most of the predators in different crops (wheat fodder and brassica) depicted a straight line showing least changes in nearly all monthly samples with s. graminum. by using such results species specific biological control can be implemented against targeted pests of the cropland.