Molecular tool for identification of closely related species of Trichogramma (Hymenoptera: Trichogrammatidae): T. rojasi nagaraja & nagarkatti and T. lasallei pinto

Abstract

The sequence of the ITS2 (internally transcribed spacer 2) region of the rDNA was used to identify two closely related Trichogramma species: T. rojasi and T. lasallei, the second species recently reported in Brazil. The DNA of the samples was extracted using Chelex 100. The PCR product was linked to a pGEM-T® vector and both were then placed into Petri dishes to grow white colonies, which demonstrate the correct ligation between the vector and the DNA. From these colonies, 10μl were purified and sequenced using a special kit, and the sequences aligned using the ESEE 3.0 software. Specific primers were efficient to amplify the ITS2 rDNA region of the Brazilian Trichogramma. The sequence of each species differed in length and in nucleotide position, showing that they are distinct. Thus, the results show that this technique is a good tool to identify Trichogramma cryptic species, otherwise difficult to identify when using only morphological characters.