Integrative systematics of a new species of the gall wasp genus Belonocnema Mayr (Cynipidae, Cynipini) on the Mesoamerican live oak Quercus oleoides (Fagaceae) and its associated hymenopteran community

Belonocnema Mayr (Cynipidae, Cynipini) is an oak gall wasp genus currently known by three described species distributed in the southern and southeastern U.S. and northern Mexico, all associated with live oaks of the Quercus section Virentes. Here, we conducted an integrative systematic study of a new species of Belonocnema , B. mesoamericana Zhang, Zaldívar-Riverón & Fernández-Flores, sp. nov ., reared from galls of the live oak Quercus oleoides Schltdl. in the state of Veracruz, Mexico. We morphologically described the sexual and asexual generations of the new species and their galls, molecularly characterized it based on the DNA barcoding locus, reconstructed its phylogenetic affinities using multilocus data from Ultraconserved Elements, and identified its associated hymenopteran community. The new species is morphologically similar to its sister species, B. kinseyi Weld, though it can be distinguished by color and sculpture features, as well as by the sexual generation forming velvety rootlet galls. Since Q. oleoides is widely distributed across Mesoamerica, we expect the new species to have a broader distribution. A considerably high species richness and phylogenetic diversity of the hymenopteran community associated with the galls were recovered, with 43 morphospecies belonging to 15 genera and 13 families, of which 41 were found in the asexual generation and only three in the sexual generation. This study increases the systematic knowledge of a poorly known Cynipini genus and highlights the extraordinary, yet neglected, insect diversity associated with galls, especially in the Neotropics.