Desmopachria convexa group

Miller, Kelly B., 2020, Two new species of Desmopachria Babington, 1841 in the D. convexa species group (Coleoptera, Adephaga, Dytiscidae, Hydroporinae, Hyphydrini), ZooKeys 923, pp. 65-77 : 65

publication ID

https://dx.doi.org/10.3897/zookeys.923.47104

publication LSID

lsid:zoobank.org:pub:B10E9E71-8A43-4560-BBAC-47F52E401045

persistent identifier

https://treatment.plazi.org/id/72B3E65F-87F9-556A-BBEF-581CB3A0DDEF

treatment provided by

ZooKeys by Pensoft

scientific name

Desmopachria convexa group
status

 

The Desmopachria convexa group View in CoL

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 View Figures 11–36 ) or trifid (e.g., Fig. 11 View Figures 11–36 ) with the exception of D. pilosa Miller (apically simple, Fig. 52 View Figures 37–57 ) and D. majuscula Young (seemingly absent, Fig. 34 View Figures 11–36 ). 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 View Figures 1–10 , 5 View Figures 1–10 ) 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 View Figures 1–10 , 10 View Figures 1–10 ). 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 Régimbart, 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.

Kingdom

Animalia

Phylum

Arthropoda

Class

Insecta

Order

Coleoptera

Family

Dytiscidae

Genus

Desmopachria