Pediobius foveolatus (Crawford)

Pediobius faveolatus is the key parasitoid of grubs of Henosepilachna vigintioctopunctata infesting brinjal and potato. The highest parasitism of grubs collected from around Bangalore, Karnataka is generally recorded in the grubs collected in March to July, the parasitism reaches as high as 77% in certain areas around Bangalore where pesticides are used judicially and with the advice of monitoring scouts. The parasitoid has been successfully introduced from India to Maryland, USA and has proved very effective in suppressing the Mexican bean beetle population there. But it fails to overwinter, hence it has to be produced and released in the season, till a strain from colder regions is identified and introduced.

The initial culture of Pediobius foveolatus is started from the superior strain identified based on its past record. Once sufficient quantity of the laboratory culture is established the scaling up of the culture starts. Two hundred adults are kept in jars (18 x 15 cm) and provided with 10% sucrose solution. The parasitoids are provided 500 third instar grubs of Henosepilachna for 24 hrs. The parasitised grubs are removed and kept in separate cages for further development on a buquet of brinjal leaves. The female adults live for 8 days and the male 10 days. Six days after parasitization the parasitised grubs (showing bulging of the ventral surface of the abdomen, turning brown and sticking to the plant food substrate by its anal end) are removed and kept in a separate container for adult emergence, in each jar about 10-12 parasitised grubs are kept which ultimately yield 200 adults and to these adults 500 third instar grubs are exposed and the production procedure continues. Different generations (4) are completed in 10-17 days each.