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
Hygrotus
Stephens, 1828
Type species
:
Dytiscus inaequalis
Fabricius, 1777
: 239
, by subsequent designation of
Curtis (1835: pl. 531)
.
Herophydrus
Sharp, 1880
: cxlviii; type species:
Hydroporus hyphydroides
Perris, 1864
: 277
(=
Herophydrus guineensis
(Aubé 1838: 455))
, by monotypy.
n. syn.
Dryephorus
Guignot, 1950
: 150
; type species:
Coelambus nodieri
Régimbart, 1895
: 37
, by original designation of
Guignot (1950: 150)
.
n. syn.
Heroceras
Guignot, 1950
: 150
; type species:
Herophydrus descarpentriesi
Peschet, 1923
: 176
, by original designation of
Guignot (1950: 150)
.
n. syn.
The newly defined subgenus
Hygrotus
s. str.
includes siX species previously included in the former subgenus
Hygrotus
s. str.
, the single species of former genus
Heroceras
(
H. descarpentriesi
) and all 44 species (one of them bitypic) of the former genus
Herophydrus
(see
Fig. 2
and
Table 1
).
Diagnosis.
Body shape short oval to moderately elongate oval (TL/MW ca. 1.7–1.8); species of former
Hygrotus
s. str.
and
Heroceras
small (TL
2.8–3.6 mm
) (see
Fig. 8
for
H.
(s. str.)
inaequalis
and
Fig. 17
for
H
. (s. str.)
descarpentriesi
) and species of former
Herophydrus
small to large (TL
2.6–7.4 mm
) (see
Fig. 16
for
H.
(s. str.)
guineensis
). Head of species of former
Hygrotus
with anterior clypeal margin evenly and semicircularly rounded, border produced forwards and with complete bead (see
Figs 44 and 45
for
H.
(s. str.)
inaequalis
); species of former
Herophydrus
and
Heroceras
with anterior clypeal margin truncate, straight or slightly emarginated, border not produced forwards; bead present, but in many species narrowed in medial part (see
Fig. 43
for
H.
(s. str.)
guineensis
), in others medially obsolete or widely reduced eXcept before eyes (cf. AppendiX). Antennomeres simple, not broadened eXcept in
H.
(s. str.)
descarpentriesi
, with antennomeres of both seXes, but especially males, strongly dilated (
Fig. 17
). Elytra with margin in lateral view rather strongly ascending to shoulder (similar to
Fig. 54
); epipleuron comparably broad, broader than mesotibia distally; carina meeting inner margin of epipleuron forming a comparably small angle (<ca. 135°; similar to
Fig. 49
). Elytral pattern diverse (vittate, dotted or uniform); venter black or brown. Last abdominal ventrite without deep depression.
Aedeagus with median lobe robust, distal part very diverse in ventral view, more or less symmetric (see
Figs 22 and 27
for
H.
(s. str.)
inaequalis
and
H.
(s. str.)
guineensis
) or at most slightly asymmetric in some former
Herophydrus
(see figures in
Biström & Nilsson 2002
); parameres with condylar process generally short, forming an obtuse angle with distal part (see
Fig. 32 and 39
for
H.
(s. str.)
inaequalis
and
H.
(s. str.)
guineensis
). Male metatarsal claws of equal length.
Distribution.
Palaearctic, Nearctic, Ethiopian and
Oriental
. Species of the former subgenus
Hygrotus
(the
H.
(
Hygrotus
)
inaequalis
-group in
Fig. 2
) are distributed in Europe, northern Africa, Asia and northern America (reaching northern
MeXico
); species of former
Herophydrus
occur mainly in Africa, with five species in the Palaearctic, one (
H.
(s. str.)
musicus
) reaching the
Oriental
region and
H
. (s. str.)
morandi
(Guignot, 1952)
known from
Cambodia
only;
H.
(s. str.)
descarpentriesi
is endemic to mountainous regions in south-eastern
Madagascar
.
Main habitat
types
.
The subgenus includes species typical of lentic and lotic freshwater environments; some species can be found in inland mineralised or coastal brackish waters, such as for eXample
H.
(s. str.)
musicus
(
Millán
et al
. 2006
)
. The latter species can also be found in mineral and thermal spring-pools (pers. communication by
J. Hájek
,
Prague
,
Czech Republic
). The habitat of most African species of the subgenus is poorly known.