Prevalence and Relative Abundance of Coccinellid Beetles on Mustard (Brassica campestris) Crop

The experiment was conducted during November, 1994 to January, 1995 for assessing the number of coccinellid species present, their prevalence relating plant age and stages and also their relative abundance on mustard crop. Seven different coccinellid species were found of which four were identified as Micraspis discolor, Micraspis sp., Coccinella transversalis and Coccinella septempunctata. The remaining three could not be identified and were designated as M1, M2 and M3. Of these, the species Micraspis discolor was the most abundant in terms of number and was also present for the longest period. These coccinellid predators appeared in the fields two weeks after sowing (WAS) and were present up to the harvesting stage of the crop with the maximum population recorded during the flowering stage from mid December to last January. In terms of relative abundance, Micraspis discolor was also found to be the dominant one and relativity was the highest 83.23% and lowest M2 and M3 respectively, at the mid of December.