A new classification of the tribe Hygrotini Portevin, 1929 (Coleoptera: Dytiscidae: Hydroporinae)
Author
Fery, Hans
text
Zootaxa
2017
2017-05-05
4317
3
499
529
journal article
32201
10.11646/zootaxa.4317.3.4
ca0d653d-32de-4c75-a95d-d9a4690d6fda
1175-5326
884766
5Fd492A4-D41D-4F37-A121-Ffa680E7E778
Subgenus
Coelambus
Thomson, 1860
Type species
:
Dytiscus confluens
Fabricius, 1787
: 193
, by subsequent designation of
Zaitzev (1953: 129)
.
FIGURES 41–48.
Head with details of clypeal rim of (41)
Hygrotus
(
Leptolambus
)
impressopunctatus
, (42)
H
. (
Hyphoporus
)
solieri
, (43)
H
. (s. str.)
guineensis
, (44)
H
. (s. str.)
inaequalis
, (45) idem in lateral view, (46)
H
. (
Coelambus
)
confluens
(the lighter area before the anterior border of the clypeus is the "clypeal stripe"; see Appendix), (47)
H
. (
Leptolambus
)
masculinus
and (48) idem in lateral view.
FIGURES 49–55. (49–53):
Epipleuron with oblique epipleural carina and genicular fossa of: (49)
Clemnius
(s. str.)
berneri
, (50)
Hygrotus
(
Leptolambus
)
polonicus
polonicus
, (51)
H
. (
Coelambus
)
caspius
, (52)
H.
(
Leptolambus
)
impressopunctatus
and (53)
Rhithrodytes agnus
; epipleural carina (c) and inner margin of epipleuron (m) including angle mentioned in diagnoses of subgenera.
(54–55):
Elytral margin in lateral view of: (54)
H
. (
Coelambus
)
caspius
(strongly ascending to shoulder) and (55)
Clemnius
(s. str.)
berneri
(moderately ascending to shoulder) (Figs 52 and 53 are reproduced from Fery 2013 and from Fery 2016 with the permissions of F. Gusenleitner, Linz, Austria, and G. Foster, Ayr, UK, respectively).
The subgenus
Coelambus
contains eight Palaearctic and one Nearctic species (
Hygrotus
(
C.
)
punctilineatus
(Fall, 1919))
.
Diagnosis.
Body shape moderately to elongate oval (TL/MW ca. 1.7–2.0); small to medium sized species (TL 3.0–
4.5 mm
) (see
Fig. 9
for
H.
(
Coelambus
)
confluens
). Head with anterior clypeal margin truncate and slightly emarginated, border not produced forwards; bead absent. Antennomeres simple, not broadened. Elytra with margin in lateral view strongly ascending to shoulder (see
Fig. 54
for
H
. (
Coelambus
)
caspius
(Wehncke, 1875))
; epipleuron comparably narrow, narrower than mesotibia distally; carina meeting inner margin of epipleuron forming a comparably wide angle (<ca. 150°; similar to
Fig. 51
). Elytra light yellowish (more yellowish brown in
H.
(
Coelambus
)
ahmeti
Hájek, Fery & Erman, 2005
), distinctly vittate (in some species/individuals vittae strongly reduced in anterior half). Venter usually black, but females of some species (e.g.
H.
(
Coelambus
)
pallidulus
) with abdomen at least in part yellow or brownish. Last abdominal ventrite without deep depression.
Aedeagus with median lobe elongate, very slender (distal half very thin in lateral view), symmetric or almost symmetric (e.g. in
H.
(
Coelambus
)
enneagrammus
(Ahrens, 1833)
, and
H.
(
Coelambus
)
confluens
; see
Figs 23 and 24
). Parameres with condylar process rather long and forming an almost right angle with distal part (
Figs. 37 and 38
for
H.
(
Coelambus
)
enneagrammus
and
H.
(
Coelambus
)
confluens
, respectively). Male metatarsal claws of equal length.
Distribution.
Mainly Palaearctic, with one species in
Canada
and northern
USA
(
Hygrotus
(
Coelambus
)
punctilineatus
).
Main habitat types.
The subgenus includes species typical of both lentic and lotic habitats, with varied salinity tolerance going from freshwater to hypersaline.