Molecular phylogenetics of Eretmocerus Haldeman (Hymenoptera: Aphelinidae) imported and released in the United States for control of an invasive species of Bemisia Quaintance & Baker (Hemiptera: Aleyrodidae)

Eretmocerus Haldeman (Hymenoptera: Chalcidoidea: Aphelindae) is arguably the most important and effective genus of whitefly parasitoids used in classical biological control programs. One such program was initiated in North America following the invasion of Bemisia tabaci Middle East-Asia Minor 1, one of the world’s worst invasive species. From 1990 to 2002, interagency cooperation between USDA-APHIS and Florida’s Division of Plant Industry resulted in the release of eight exotic Eretmocerus species in Arizona, California, Florida, and Texas. Two of the undescribed species are morphologically cryptic with Eretmocerus emiratus Zolnerowich & Rose yet are among the most abundant and important B. tabaci parasitoids in Arizona (E. sp. nr. emiratus from Ethiopia) and Florida (E. sp. nr. emiratus from Sudan). Hesitation to describe these species as new, despite their establishment and ecological significance, reflects uncertainty in morphological species limits within the genus as well as the lack of a molecular framework to assess putative relationships and species boundaries. We used an integrative taxonomic approach - a combination of morphological characters, molecular sequence data, and species delimitation algorithms - to characterize these taxa, resulting in the description of the Ethiopian population as a new species that is more closely related to E. mundus Mercet than E. emiratus. The population from Sudan is found to be conspecific with E. emiratus based on molecular evidence, and the species concept of E. emiratus is expanded to accommodate the morphological diversity contained within the Sudan population.