Testing the monophyly of Ageniellini genera (Hymenoptera: Pompilidae) with a molecular phylogeny, and the search for diagnostic morphological characters

Ageniellini (Pompilidae) is a cosmopolitan tribe, with seven genera in the Neotropical region. Ageniellini wasps are notable for their unusual, specialized behaviors associated with prey capture and nesting. Females amputate the legs of their spider hosts, and some species build mud nests communally. Despite their intriguing biology, the taxonomy of Ageniellini has been neglected by systematists. Males of the genera Ageniella, Phanochilus, and Priocnemella have been distinguished by few characters, and are historically difficult to identify. We have found these characters to be inconsistent; thus, monophyly is not confirmed for these genera. Here, we tested if these diverse genera of Neotropical Ageniellini are monophyletic and searched for characters that support them. We studied 14 male genitalia characters for the first time, aiming to distinguish taxa by primary genitalic features. A phylogeny of 41 species was reconstructed with a Bayesian approach using two nuclear genes. Taxonomic characters, including male genitalic features, were mapped onto the tree using SIMMAP. Preliminary results support the paraphyly of all three genera: species of Phanochilus and Priocnemella were nested within the genus Ageniella; Phanochilus species were recovered in multiple clades, as sister to either Priocnemella or Ageniella species. The genitalic character, presence of hairs on ventral surface, is a synapomorphy for the clade including Priocnemella and Phanochilus. More study is needed, but our preliminary results confirm that historical morphological assessments were not correctly interpreting evolution of the group, and new features must be found. Male genitalia offer an exciting potential source of distinct and informative characters.