Robuta

https://content.ces.ncsu.edu/print_image/14370 Chelostoma philadelphi body and tunnel size relative to a penny relative to chelostoma body tunnel size https://journals.ku.edu/melittology/article/view/11760?articlesBySameAuthorPage=4 On the classification of North American Chelostoma (Hymenoptera: Megachilidae) | Journal of... on the north american classification chelostoma hymenoptera https://journals.ku.edu/melittology/article/view/11760/11218 View of On the classification of North American Chelostoma (Hymenoptera: Megachilidae) on the north american view classification chelostoma