An unexpected new genus of panurgine bees (Hymenoptera, Andrenidae) from Europe discovered after phylogenomic analysis

Abstract

Establishing a higher classification of bees based on morphology alone can fail to capture evolutionary relationships when morphological characters either vary very little between distantly related groups, or conversely vary greatly between closely related species. This problem is well represented in the subfamily Panurginae, for which a recent global revision based on phylogenomic data unexpectedly revealed that two Old World species previously placed inCamptopoeumSpinola andFlavipanurgusWarncke, are in fact most closely related to each other, and together form a sister group relationship to the remainingFlavipanurgusandPanurgusPanzer combined. To rectify this situation, we here establish an expanded phylogenomic data set of Old World Panurgini and re-assess generic and subgeneric concepts for the tribe. To solve the paraphyly ofCamptopoeumandFlavipanurgus, we establish the new genusHalopanurgusgen. nov.containing the speciesH. baldocki(Wood & Cross),comb. nov.andH. fuzetus(Patiny),comb. nov., both of which are restricted to coastal sands, saltmarshes, and inland saline lagoons in the extreme south of Portugal and south-west of Spain. Re-evaluation of four recently used subgenera inPanurgusstrongly supports a simplified classification of two subgenera;PachycephalopanurgusPatiny,stat. rev.includingMicropanurgusPatinysyn. nov., andPanurguss. str. includingEuryvalvusPatiny.Pachycephalopanurgusspecies seem to be oligoleges of Asteroideae (Asteraceae), whereasPanurguss. str. may be oligoleges of Cichorieae (Asteraceae). Our findings reinforce the challenges of establishing a phylogenetically sound classification of Panurginae using morphology alone and illustrate that even in well-studied regions like Europe unrecognised genera can persist in underexplored corners of the continent.