NUMERICAL RESPONSE OF LIPOLEXIS OREGMAE (HYMENOPTERA : APHIDIINAE) AGAINST APHIS CRACCIVORA (HEMIPTERA : APHIDIDAE)

Abstract

The performance of the parasitoids is usually evaluated by studying its life-table which involves the statistics of birth and death rate illustrating the condition of the biological community. The study of numerical response provides the data for the calculating the number of parasitoid needed to regulate the pest population. Thus, parasitoid density also influences the lifetable statistics of the parasitoids especially net fecundity, total fecundity, progeny sex ratio etc. Lipolexis oregmae is very common parasitoid and found abundantly in several districts of Bihar (India). Few aspects of biological and ecological studies were made by few workers. We need more information about it especially in a relation to the future production. Aphis craccivora (cowpea aphids) is a sporadic pest in Bihar and abundantly found in all localities. This aphid has an extensive host range, hence the performance of the parasitoids at different density on three host plants Lablab purpureus (=Dolichos lablab), Phaseolus sinensis and Vicia faba on A. craccivora was investigated. At six parasitoid, the maximum fecundity of L. oregmae was recorded on V. faba (64.20 ± 6.85) and minimum on P. sinensis ( 53.20 ± 4.65).