Observations on Heliothis peltigera (Schiff.) (Lep., Noctuidae) and its natural enemies in Anand (Gujarat State, India).
Heliothis peltigera (Schiff.), which in other countries is a pest of several economic plants, was found in 1972-73 at Anand in the Indian State of Gujarat infesting the weed Acanthospermum hispidum. The insect and the weed were closely synchronised in their life-cycles; both appeared at the onset of the monsoon in July and disappeared in October or November. The larvae fed mainly on the growing tips and terminal leaves of A. hispidum, the young larvae forming characteristic webs on the leaves. The extent of damage, population density and natural parasitism were recorded and the results are shown in tables. The peak period of larval activity was in September, when up to 53% damaged shoots and 35 larvae/100 shoots were observed. The parasites found comprised Trichogramma chilotraeae Nagaraja & Nagarkatti in the eggs; the tachinids Carcelia illota (Curr.) (Eucarcelia illota), Palexorista laxa (Curr.) and Exorista xanthaspis (Wied.), and the ichneumonids Campoletis maculipes (Tschek), Eriborus sp. and Pristomerus sp. in the larvae; and the braconid Chelonus heliopae Gupta in both eggs and larvae. All except the last 2 species are new records as parasites of H. peltigera. Predators found for the first time attacking this noctuid were the ant Camponotus sericeus (F.) and the larvae of Chrysopa carnea Steph., both of which preyed on the young larvae. The survey on H. peltigera showed that it feeds primarily on A. hispidum and is of some benefit in controlling this weed in Gujarat State, but that it is not a serious pest of any economic plant grown there; in any case its numbers are kept low by the high degree of egg parasitism. Distribution, food-plants and natural enemies of the noctuid in different countries are reviewed from the literature.