Detecting parasitised eggs with polymerase chain reaction and DNA sequence of Trichogramma australicum Girault (Hymenoptera: Trichogrammatidae)

The nuclear internal transcribed spacer 2 (ITS2) regions of the egg parasitoid Trichogramma australicum Girault, cotton bollworm Helicoverpa armiger a (Hubner) and Helicoverpa punctigera (Wallengren) were amplified by the polymerase chain reaction (PCR) to yield 408, 588 and 644 b.p. fragments, respectively. DNA sequence information was used to design unique primers for specific amplification of T. australicum DNA from individual parasitised eggs. Helicoverpa australicum-specific PCR products were first visible 12 h after eggs were parasitised. This PCR assay can be used to monitor wasp populations under field conditions.