Partial cytochrome oxidase II sequences distinguish the sibling species Trichogramma minutum Riley and Trichogramma platneri Nagarkatti

The egg parasitoids Trichogramma minutum Riley and Trichogramma platneri Nagarkatti are commonly used in North America for the control of Lepidoptera in orchards. These species are morphologically indistinguishable, but reproductively incompatible. An easy identification technique is highly desirable, because release of the wrong species in the native area of the other species may result in a depression of intended biological control. Here we show that the DNA sequences of the mitochondrial cytochrome oxidase II (COII) gene differ between the species. These differences can be visualized by restricting the COII PCR product with the restriction enzyme VspI. This method makes a rapid identification of these economically important sibling species possible.