Molecular Characterization of Trichogramma Cacoeciae Strains (Hymenoptera: Trichogrammatidae) from the South West of Tunisia

A survey of egg parasitoids of the genus Trichogramma (Hymenoptera: Trichogrammatidae) was carried out in the South West Tunisian oases during spring and summer 2009. Parasitoids were collected by exposing sentinel eggs of the host Ephestia kuehniella Zeller (1879) (Lepidoptera: Pyralidae) in different areas of the Djerid and the Gafsa oases. Parasitized egg samples were reared separately in the laboratory for emergence of parasitoids. These were further reared in separate lines and processed by molecular techniques. Following PCR-amplification of the ribosomal DNA (rDNA) internal transcribed spacer 2 (ITS-2), restriction endonuclease digestions (by EcoRI and MnlI) and bioinformatic analyses allowed species and strains characterization. The collected strains were found to belong to the Trichogramma cacoeciae Marchal (1927) species. Moreover, the molecular analysis revealed that the size of the PCR products of the ITS-2 region ranged from 550 to 600 bp. The collected strains were found different from other reported T. cacoeciae strains and even those previously identified in Tunisia. The sequences of the (ITS-2) region of these newly isolated strains were determined and deposited in the GenBank database. Further investigation should permit the biological characterization of these strains to be used in IPM programs.