Allorhogas pyralophagus Marsh

Allorhogas pyralophagus is a primary ecto-parasitoid of Acigona loftini a pest of several graminaceous plants in the New World. It has been introduced to India for evaluation against sugarcane and paddy tissue borers.

50 newly emerged males and females of Allorhogas pyralophagus are released in a glass cylinder (5.5 cm dia x 20.5 cm h) and provided with 50 per cent honey and water. The cylinder is secured at both ends with muslin cloth with the help of two rubber bands on each side. The cylinder with parasitoids is kept in indirect sunlight for 30 minutes for first 2 days to stimulate mating.

Third or fourth instar larvae of Chilo partellus are placed in a paper clipping straw with cotton stubs placed between the larvae. After packing the larvae, the open ends of straws are closed with cotton plugs. The paper straws containing larvae are placed vertically in the cylinder containing mated A. pyralophagus for two days. The female parasitoids paralyses the larvae and insert one to eight eggs in each larva. One female parasitises 2-3 larvae in each exposure and could be used for 3 exposures. The eggs hatch in two days and the larval and pupal periods are 5-7 and 10-12 days, respectively. The adult female lives for 20-30 days. The exposed straws are placed in a separate cage, bottom of which is filled with sterilized sand mixed with 5 per cent sterilized water by volume. The straws are cut open after 8-10 days and parasitoid cocoons are collected. The cocoons are kept in glass tubes on small plastic cages and just before the adult parasitoids are about to emerge 50 per cent honey and water soaked cotton swabs are placed for feeding by the emerging adults. Seventy five per cent of the mated females are used for field release and the remaining for continuing the culture.