Three New Species in the Desmopachria striola Species-Group of Desmopachria Babington, 1841 (Coleoptera: Adephaga: Dytiscidae: Hydroporinae: Hyphydrini)
Author
Miller, Kelly B.
Author
Wolfe, G. William
text
The Coleopterists Bulletin
2019
2019-09-22
73
3
621
628
http://dx.doi.org/10.1649/0010-065x-73.3.621
journal article
10.1649/0010-065X-73.3.621
1938-4394
5402222
urn:lsid:zoobank.org:pub:8A2A3D9E-778A-453B-8419-27163E896DB3
The
Desmopachria striola
species-group
Diagnosis.
The
Desmopachria striola
speciesgroup is defined as those
Desmopachria
species
with a distinct sutural stria on the elytron (
Young 1980
,
1990
;
Miller 2001
). The group is heterogeneous, and the male genitalia are dissimilar across the entire group as currently defined. Several species, however, including
Desmopachria grouvellei
Régimbart
,
Desmopachria ruginosa
Young
,
Desmopachria striola
Sharp
, and those species described herein seem to have similar genitalia with the median lobe in ventral aspect “shouldered” medially (laterally expanded) to varying degrees and the lateral lobe apically with a more-or-less abruptly obliquely bent flat lobe (
e.g
.,
Figs. 3, 4
). Even so, this group requires additional investigation to determine if it is natural and what is its diagnostic combination.
Comments.
Guignot (1950)
described the subgenus
Pachriostrix
(
type
species
D. grouvellei
) to include
Desmopachria
species
with a distinct sutural stria.
Young (1980)
retained the definition of the group but noted that the group may well be artificial given the diversity of forms of the male genitalia and other features. He later noted the same thing when revising the genus (
Young 1990
), at which time he also described a new species and removed some from the subgenus.
Miller (2001)
discarded the
Desmopachria
subgenera, including
Pachriostrix
, and instead recognized this group of species as the
D. striola
species-group. The group remains problematic. Several species, including the new species described herein and
D. striola
, have seemingly similar male genitalia with features as described under the diagnosis above, whereas others (specifically
Desmopachria amyae
Miller
,
Desmopachria chei
Miller
, and
Desmopachria fossulata
Zimmermann
) have rather different male genitalia but remain included because of the sutural stria on the elytron (
Fig. 1
).
Desmopachria amyae
has genitalia similar to those of species in the
D. portmanni
species-group, especially
Desmopachria duodentata
Braga and Ferreira Jr.
Desmopachria chei
has male genitalia more similar to that of
Desmopachria rex
Gustafson and Miller
and
Desmopachria varians
Wehncke
than to other species in the
D. striola
species-group. It certainly seems possible that the sutural stria is an unreliable character as an indicator of monophyly, though such a dispositive evaluation will require a larger phylogenetic analysis of the group.
Young (1980)
included
D. fossulata
in
Pachriostrix
and later included an image of the genitalia of the species based apparently on a drawing from J. Balfour-Browne (
Young 1990
); inexplicably he did not key it or address the species further in that revision. The genitalia (
Fig. 18
) are rather different from those of other
D. striola
species-group members, and it is not clear that it comports well with the definition of the group.