Abstract
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.
