Influence of host plants on parasitism of Helicoverpa armigera (Lepidoptera: Noctuidae) by two egg parasitoids, Trichogramma chilonis and Trichogramma achaea (Hymenoptera: Trichogrammatidae)
Reddy, G.V.P.; Manjunatha, M.
International Pest Control 41(6): 223-225
1999
ISSN/ISBN: 0020-8256 Accession: 003476518
Trichogramma chilonis and T. achaea [T. achaeae], are important egg parasitoids of Helicoverpa armigera in India. The effect of the host plants on parasitism of H. armigera eggs by T. chilonis and T. achaeae was studied during 1992-93 and 1993-94 in the field in Karnataka on the following eight plants: cotton (Gossypium hirsutum), soyabeans (Glycine max), maize (Zea mays), sunflower (Helianthus annuus), sorghum (Sorghum bicolor), safflower (Carthamus tinctorius), pigeon pea (Cajanus cajan) and chickpea (Cicer arietinum). Parasitism was low on chickpea (0% to 1.5%) and on safflower (4% to 13%). Moderate to high levels of parasitism (16% to 63%) were recorded on sorghum, pigeon peas, sunflower, maize, soyabeans and cotton. These parasitoids should be released in crops such as cotton, soyabean, maize, sunflower and pigeon pea on which H. armigera is a very serious pest in India. However, the results suggest that the release of these egg parasitoids into chickpea and safflower are unlikely to enhance parasitism levels.