Species Diversity in the Braconid Wasp Genus Allorhogas (Doryctinae) Associated With Cynipid Galls on Live Oaks (Quercus: Fagaceae) Using Natural History, Phylogenetics, and Morphology

Abstract

Abstract The discovery of new biodiversity, during an age of unprecedented extinction, is vital for all the life sciences and the quality of human life. One ecologically and economically important group that requires attention is the hymenopteran family Braconidae, which is estimated to include thousands of undescribed species. Here we assessed the genetic structure and species diversification in the braconid wasp genus Allorhogas Gahan (Doryctinae) that were reared from galls of five cynipid wasp species associated with three live oak species (Fagaceae: Quercus: subsection Virentes) in the southeastern United States. We explored genetic variation in the single-locus barcoding COI region of the mitochondrial DNA (mtDNA), and conducted analyses with different DNA sequence-based species delimitation approaches both for the above marker and genome-wide nuclear data using ultraconserved elements (UCEs). We found high variation in the mtDNA barcoding region among specimens of Allorhogas reared from galls made by different cynipid species in distinct plant organs and among specimens reared from the same type of gall from two separate geographic regions. In addition, our analyses of mtDNA and multilocus nuclear data were concordant in consistently delimiting at least five genetic lineages. We combined this molecular evidence with morphological data to describe four new species and redescribe the type species of the genus, Allorhogas gallicola Gahan, which exhibited similar morphological, ecological, and biogeographic characteristics to the four new species. This study highlights the importance of carrying detailed rearing surveys to uncover the intricate species interactions and species diversity that is present in gall-former systems.