Identificación molecular de especies crípticas de Trichogramma Westwood (Hymenoptera: Trichogrammatidae) de importancia agrícola en México

摘要

align="justify"> face="verdana" size="2">Trichogramma parasitic wasps often are cryptic species and can not be distinguished because of their small size and the plasticity of their morphological traits. The species identity of Trichogramma has been based on the morphology of the male genitalia and flagellar structures, this presents a particular problem for parthenogenetic forms. The objective here was to identify by molecular methods cryptic species of Trichogramma occurring in agricultural fields of Mexico. We identified the cryptic species T. pretiosum, T. fuentesi y T. exiguum, and the non cryptic species T. atopovirilia y T. pintoi. A identification dichotomous key to species was constructed using as taxonomic characters the size of the internal transcribed spacer 2 (ITS2) region of ribosomal DNA and the difference in restriction length polymorphism of species. Also the ITS2 regions were sequenced coupled with ITS2 sequences from GenBank and the percents of similarity and divergence were calculated between species. This molecular tool can solve identification of cryptic species of Trichogramma from Mexico.