Based on biological characteristics
i. r-pest: They possess a high rate of potential increase, strong dispersal and host finding ability. They include major pest such as locust and aphid.
ii. k-pest: They possess a low rate of potential increase, grater interspecific competitive capability, more specialized food habit and bigger size. They seldom become an economic pest due to human intervention, climatic pattern change.
iii. r-k pest: They possess a various mixture of characteristics of r and k pest. E.g. Nila parvataon rice.