Abstract
Efficiency of various techniques used in the precipitation reaction was evaluated to identify the predator species of the diamondback moth, Plutella xylostella (L). Using 3rd to 4th instar larvae of P. xylostella as an antigen, the antiserum was prepared by immunizing a rabbit with it. The larvae were reared on seedlings of radish (Raphanus sativus L.) in the laboratory. The antiserum against P. xylostella constituents reacted with the homologous constituent, and also crossreacted with R. sativus. Thus the antiserum specific for P. xylostella was prepared by absorbing the antibody with the saline extracts of R. sativus. The Micro-Ouchterlony method (MO method) was sensitive enough to enable the detection of whole-body extracts of 3rd-4th instar larvae, pupae and adults of P. xylostella. The anti-P. xylostella serum did not induce cross-reactions with the constituents of other arthropods inhabiting the cabbage fields. It was concluded that the MO method was most useful for the identification of predators of P. xylostella, as compared with electrosyneresis or the precipitin ring test.
