Hyposoter didymator Thunberg

Hyposoter didymator, the exotic parasitoid has been imported from southern Europe in 1985. H. didymator is an important parasitoid of Helicoverpa armigera and Helicoverpa peltigera Denis and Shiffermuller in the distribution zones of these pests on several crops.

The parasitoid could be successfully produced on 4-5th instar larvae of Spodoptera litura and Helicoverpa armigera.

Twelve females and 6 freshly emerged adult males are confined in a 30 cm wooden cubical cage. The bottom and top of the cage is lined with water soaked sponge to provide adequate humidity. The parasitoids are fed on 10% honey solution provided in soaked cotton swabs. The pre-oviposition period and multiple mating is completed in three days. Three hundred 4 day S. litura larvae are exposed to 12 females for 24 hours. The larvae are placed on castor leaf bouquet which is prepared by making 10-15 small holes in the lid of one litre jar, filled with water and the petioles of leaves are inserted in each hole. The bouquet is then kept in the one 30 cm3 cage or in a cylindrical cage 25 cm in diameter and 45 cm in height. The frame is made up of 3 mm thick galvanized iron wire. The frame is enclosed in a nylon mesh (225 holes/sq cm) covering. This cage is kept in (30 x 30 cm) aluminium tray having thin layer of sterilized sand. After four days of parasitisation the unparasitised larvae are removed based on their relatively higher growth rate. On the 7th day, most of the larvae move to the nylon mesh in the cage and the parasitoid larvae wriggle out of the host body on 9th day. Cocoon formation is over by 11th day. On 12th day they are hard enough to be removed from the mesh with the help of brush. Cocoons are collected in petridish and allowed to emerge in 30 cm3 cage. Adults can be stored at 10°C for 20 days by maintaining RH at 75%.