Molecular identification of Trichogramma species from Pakistan, using ITS-2 region of rDNA

Molecular techniques were used to distinguish six Trichogramma species (Hymenoptera, Trichogrammatidae) collected from different ecological zones of Pakistan: T. chilonis (Ishii), T. chilotraeae (Nagaraja and Nagarkatti), T. evanescens (Westwood), T. pintoi (Voegele), T. euproctidis (Girault, 1911), T. siddiqi (Nasir and Schöller). Electrophoresis of PCR-amplified ribosomal DNA internal transcribed spacer 2 (ITS-2) followed by restriction endonuclease digestions was applied. The restriction enzyme analysis was carried out in order to obtain species specific banding patterns. To optimize the amplification and sequence reaction, two new primers were designed. The sequence of each species distinctly differed in length and in nucleotide composition. Thus, the results showed that this technique is a good tool to identify cryptic Trichogramma species, which are otherwise difficult to distinguish on the basis of morphological characters. Here we provide a dichotomous molecular key for Trichogramma species of Pakistan for easy and quick species identification.