none. A laboratory ecosystem consisting of host, Heliothis armigera and the ichneumonid parasitoid, Campoletis chloridae was used to determine the functional response of the parasitoid. The response was sigmoid in nature and can be described by the equation Y = K(10)-c/a+X-2 which indicates that within three hours of exposure period, in an area of 20 cm diameter times 10 cm height, the number of antennal encounters, stings and number of parasitoids emerging cannot exceed 60.805, 56.559, and 29.90 respectively even in the presence of a large number of hosts.