Karyotype analysis of Trichogramma embryophagum Htg. (Hymenoptera: Trichogrammatidae) using a new method and estimate its karyotype symmetry

Abstract

Different methods of chromosome preparation for insect are now being used across the world. Well-spread chromosomes with explicit morphology, in addition to no cell wall debris are required for karyotype investigations. Cytogenetic knowledge in Trichogramma is extremely limited. In the article, chromosome characters, karyotype and monoploid ideogram of Trichogramma embryophagum Htg. (Hymenoptera: Trichogrammatidae) were evaluated using a new method. Also, karyotype symmetry/asymmetry of this species was calculated for the first time as one of the Trichogramma species. Our results showed that the diploid chromosome number of the wasp was 2n = 10. The karyotype formula was 6m + 4a. The symmetry/asymmetry index value was 1.8. The new method resulted in higher quality metaphase plates spread and provided an ideal karyomorphology for this parasitoid which has small chromosomes.

Keywords

• ideogram
• karyotype
• 8-hydroxyquinoline
• symmetric karyotype