The functional response of interaction between Campoletis chlorideae Uchida (Hymenoptera: Ichneumonidae) and different larval stage of the host Helicoverpa armigera (Hubner) (Lepidoptera: Noctuidae) at different parasitoid density were studied in entomological laboratory, department of Zoology, D. D. U. Gorakhpur University, Gorakhpur, U. P. in summer season of 1999-2000. The host density increases, the number of antennal encounters of the parasitoid increases significantly in all the host larval age and is maximum in 2nd instar (y = -3.363+38.178 log x, r = 0.990, p < 0.001) followed by 3rd, Ist, 4th, 5th, 6th instar. With the increase in host density the number of stings by the parasitoid into the host’s body increased significantly in all the host larval age and is maximum in 2nd instar (y = -4.613+33.172 log x, r= 0.989, P < 0.001), 3rd, Ist, 4th, 5th, 6th instar of the host. Analysis of variance shows that the number of antennal encounters and stings was significantly influenced between 6 host age (F = 16.82, P < 0.001) (F = 13.85, P = 0.001) as well as between the 7 host density (F = 7.11, P < 0.001) (F = 6.809, P < 0.001). As the host density increases the number of offspring emerged increased significantly in all the host larval instar. The functional responses of C. chlorideae indicate that this parasitoid could be a candidate for biological control of H. armigera.
Maheshwar Singh, Bhuwan Bhaskar Mishra, CPM Tripathi. Effect of host’s larval age on the functional response and associated behavioral activities of the parasitoid. International Journal of Zoology Studies, Volume 2, Issue 4, 2017, Pages 36-41