Two new species of Desmopachria Babington, 1841 in the D. convexa species group (Coleoptera, Adephaga, Dytiscidae, Hydroporinae, Hyphydrini) Author Miller, Kelly B. Department of Biology and Museum of Southwestern Biology, University of New Mexico, Albuquerque, NM 87131 - 0001 USA text ZooKeys 2020 923 65 77 http://dx.doi.org/10.3897/zookeys.923.47104 journal article kbmiller@unm.edu http://dx.doi.org/10.3897/zookeys.923.47104 1313-2970-923-65 B10E9E718A434560BBAC47F52E401045 5A90240DCD655B319081ECB2F39B90B3 The Desmopachria convexa group Diagnosis. The Desmopachria convexa group is characterized in the genus by an articulable subapical process on the male lateral lobe of the aedeagus and the male median lobe either apically bifid (e.g., Fig. 15 ) or trifid (e.g., Fig. 11 ) with the exception of D. pilosa Miller (apically simple, Fig. 52 ) and D. majuscula Young (seemingly absent, Fig. 34 ). The species are extremely similar to each other in external appearance, though there are some diagnostic variations in size, shape, punctation and coloration. But externally there are often few particularly useful characters for distinguishing closely related species. Males and females are externally extremely similar, as well. There are two apparent subgroups in the D. convexa species group, those with a smaller subapical articulable appendage on the lateral lobe not extending beyond the truncate apex (e.g., Figs 4 , 5 ) and those with a larger subapical articulable appendage that is leaf-like and extends well beyond the elongate, slender oblique apex of the lateral lobe (e.g., Figs 9 , 10 ). These are referred to here as the D. convexa-convexa subgroup (with the larger subapical articulable appendage) and D. convexa-signata subgroup (with the smaller subapical articulable lobe). Desmopachria convexa-convexa species are found in North and Central America and the Caribbean, and D. convexa-signata species are found in South America. It is not clear at this time how these two groups might be related to each other or their monophyletic status, but they seem to be well-characterized by the shared articulable appendage of the male lateral lobes which is unique in Desmopachria and Dytiscidae in general. Comments. This group corresponds to the Desmopachria convexa-grana group of Young (1980) , which he later revised ( Young 1981 ). Additional new species were described by several investigators ( Braga and Ferreira-Jr. 2010 ; Miller 2001 ; 2005 ; Young 1990 ). It is possible that several other described species may belong to this species group including D. attenuata Regimbart , 1895 ( Young 1980 ), D. balfourbrownei Young, 1990, D. striga Young, 1990, and D. subfasciata Young, 1990 based on illustrations suggesting the presence of a subapical or apical articulable structure on the lateral lobe ( Miller 2001 ). These species have not been well-described making the diagnostic characteristics of the group hard to discern. It does not appear that these species correspond with either of the new species described here, however.