Comparision of biological parameters among arrhenotokous and thelytokous forms of Trichogramma (Hymenoptera: Trichogrammatidae)

Studies were carried out to assess biological attributes of arrhenotokous (sexual) and thelytokous (asexual) forms of Trichogramma species. Percent parasitization in arrhenotokous species varied from 38.10–59.53, compared to 32.68–55.62%, in thelytokous species. Mean longevity of arrhenotokous forms was 6.64 days compared to 9.45 days in thelytokous species. Developmental period was shorter in thelytokous forms, whereas mean fecundity was higher in arrhenotokous species. The implication of field use of both forms in biological control of lepidopteran pests on vegetable crop like tomato and cabbage is discussed in this paper.