A taxonomic review of the genus Oesyperus (Coleoptera: Carabidae: Harpalini)
Author
Kataev, Boris M.
text
Zootaxa
2006
1286
43
55
journal article
10.5281/zenodo.173499
a16f2339-a971-4bac-8073-9c4f9fa5f8b8
11755326
173499
Oesyperus
Andrewes, 1923
, stat. rest.
Oesyperus
Andrewes, 1923
: 444
(as a genus).
Type
species
Oesyperus unctulus
Andrewes, 1923
, designated by
Andrewes (1939: 136)
.
Oesiperus
:
Csiki, 1932
: 1210
(incorrect subsequent spelling).
Oesyparus
:
Andrewes, 1939
: 136 (incorrect subsequent spelling).
Merklia
Ito, 2004
: 107
(as a genus),
syn. n.
Type
species
Merklia pubens
Ito, 2004
(=
Oesyperus unctulus
Andrewes, 1923
), by original designation.
Merklophonus
Ito, 2005
: 53 (as a genus), nomen pro
Merklia
Ito, 2004
(non Chen, 1997),
syn. n.
Diagnosis
. Within the Selenophori group,
Oesyperus
is clearly distinguished by the combination of the following character states: dorsum punctate and pubescent; head with clypeoocular prolongations; supraorbital furrows deep, more or less straight and prolonged to neck constriction behind eyes; mandibles elongate, evenly curved and acute at apices; mentum with median tooth; antennae pubescent from apical half of second antennomere (first antennomere also with several short setae apically); elytra with rows of discal setigerous pores at least on third intervals; and tarsi pubescent dorsally. Apical orifice of aedeagus in dorsal position and covered by sclerotized plica at apex.
Description
. Size: Body small to moderate (about 6.0–11.0 mm).
Colour: Body dark, not iridescent and without metallic lustre; appendages pale.
Dorsal pubescence: Dorsum almost throughout (except for eyes, labrum and mandibles) covered with short erect black setae.
Head: Moderate or rather large, with small eyes and wide genae. Temples long, distinctly pubescent. Frontal suture narrow and shallow; clypeoocular prolongations reaching supraorbital furrows. Supraorbital furrows somewhat deep, more or less straight and prolonged to neck constriction behind eyes (
Figs 4–5
). Apical margin of clypeus weakly arcuately emarginate, not bordered, and labral base invisible in emargination. Mentum (
Fig. 6
) with a large acute tooth and with two medial setae, separated from submentum by complete suture. Epilobes narrow, slightly widened apically. Ligular sclerite narrow, with two ventroapical setae, separated from glabrous narrow paraglossae by deep notches [
Andrewes (1923)
statement that the paraglossae are setulose in
Oesyperus
is probably erroneous]. Basal palpomere not carinate. Penultimate palpomere approximately equal to or slightly longer than apical, with numerous setae on anterior margin. Mandibles rather long and acute, somewhat evenly curved to apex. Antennae moderately long, reaching elytral base, pubescent from apical half of second antennomere (first antennomere also with several short setae apically), but this pubescence sparser than in other antennomeres.
Pronotum: Sides each with one marginal seta; apical margin bordered only laterally, basal margin without distinct border (bead sometimes hardly distinct at basal angles), not ciliate on basal edge.
Elytra: Humeri more or less widely rounded at apices, without denticles. Additional ninth stria not separated from lateral furrow by convexity. Basal pore present. Each third interval with several (3–9) discal pores. Each fifth and seventh intervals without discal pores, or, discal pores, if present, hardly recognizable against backgrounds of general puncturation. Series umbilicate irregular, without a distinct gap medially.
Hind
wings: Reduced to small scales.
Ventral surface: Metepisterna wider than long, weakly narrowed posteriad. Abdominal sternites densely punctate and covered with short setae. Anal sternite rounded at apex, with two pairs of setae at apical margin.
Legs: Protibia not sulcate, with one or two preapical spines on outer margin and one ventroapical spine; apical spur slender, lanceolate. Metacoxa punctate, without additional setae. Metafemur with two or three setae along posterior margin. Tarsi densely pubescent dorsally. Metatarsus with first tarsomere much longer than second. In male, protarsomeres 1–4 moderately dilated, each with biseriate vestiture ventrally, first mesotarsomere longer than second, not dilated and without vestiture ventrally; mesotarsomeres 2–4 comparatively weakly dilated, each with biseriate vestiture ventrally.
Male genitalia: Median lobe of aedeagus (
Figs 7–14
) arcuate, with rather short terminal lamella, more or less strongly bent dorsad at apex; ventral surface of median lobe unbordered. Apical orifice in dorsal position, extending basally and covered by more strongly sclerotized plica at apex. Internal sac without any distinct sclerotized structures.
Composition and distribution
. The genus includes three species, all from southern
India
.
Remarks
. The examination of the
type
material of three species included in
Oesyperus
showed that this taxon is a member of the Selenophori genusgroup of the subtribe Harpalina because it possesses the following character states which are distinctive of this group: paraglossae glabrous, penultimate labial palpomere with several setae at anterior margin, third elytral interval with row of discal pores, and male pro and mesotarsi dilated and carring biseriate vestiture ventrally. Other character states of
Oesyperus
(distinct clypeoocular prolongations, rather long first metatarsomere, and dorsal position of apical orifice of median lobe of aedeagus) also substantiate this relationship. However,
Oesyperus
is not a member of the genus
Parophonus
, as suggested by
Noonan (1985a)
, since it clearly differs in having the rather elongate mandibles. Based on the latter character,
Oesyperus
should, in my opinion, be included in the
Oxycentrus
stock sensu
Noonan (1985b)
which comprised two phyletic lineages (groups), both restricted mainly to the Oriental Region: 1)
Hyphaerion
MacLeay
sensu lato (including
Calathomimus
Bates
,
Coleolissus
Bates
,
Tenuistilus
Habu
, and
Allosiopelus
Ito
) and 2)
Oxycentrus
Chaudoir
sensu lato (including
Oxycentropsis
Schauberger
,
Paroxycentrus
Ito
, and
Trichoxycentrus
Ito
). These two groups differ chiefly in the body shape (more or less oval, somewhat robust in
Hyphaerion
, and elongate, often cylindrical in
Oxycentrus
) and apparently represent two different adaptive morphological
types
associated with different modes of life (probably surface or litter dweller in
Hyphaerion
, and hole dweller or burrower in
Oxycentrus
). Members of
Oxycentrus
are also characterized by the particularly long mandibles, usually more elongate than those in species of
Hyphaerion
. Both
Oxycentrus
sensu lato
and
Hyphaerion
sensu lato
need revision and the taxonomic status of some of the included taxa invites further investigation. Based on the somewhat robust body and moderately long mandibles,
Oesyperus
is more similar and probably more closely related to
Hyphaerion
than to
Oxycentrus
. However, it seems to represent a separate genus clearly distinguished from the both by the pubescent body and the modified supraorbital furrows which are deep, more or less straight and prolonged to the neck constriction behind eyes. The latter character state is known to me only for some species of
Trichotichnus
Morawitz. According
to the original description (
Ito 2000
), the monotypical genus
Trichoxycentrus
possesses pubescence on the dorsal surfaces of the head and tarsi, but, unlike
Oesyperus
, the pronotum and elytra are glabrous. In addition,
Trichoxycentrus
, which is certainly closely related to
Oxycentrus
, shows other remarkable morphological characters (ligular sclerite quadrisetose, legs densely setose dorsally, prosternum and ventral surface of head densely covered with long setae) differing not only from
Oesyperus
but also from other related genera. In my opinion, the presence of dorsal pubescence in
Oesyperus
and
Trichoxycentrus
is not an indication of affinity. It is well known that many groups of
Harpalini
have dorsal pubescence and in many cases it evolved independently.
Recently,
Ito (2004)
established a new selenophorine genus
Merklia
with a single newly described species
M. pubens
. Because the name
Merklia
had already been used in 1997 for a
Lagriidae
genus,
Ito (2005)
replaced it by the new name
Merklophonus
.
Ito (2004)
described this genus without reference to
Oesyperus
and mentioned only that it “might be related to the genera
Parophonus
Ganglbauer
,
Ophoniscus
Bates
,
Trichotichnus
Morawitz,
Coleolisssus
Bates
,
Hyphaereon
MacLeay
,
Oxycentrus
Chaudoir
, and
Trichoxycentrus
N. Ito
”. Unfortunately, both
Merklia
Ito and
Merklophonus
are objective synonyms of
Oesyperus
since the
type
species of the first two taxa is conspecific with the
type
species of
Oesyperus
(see below).
It is interesting to note that, although all three species of
Oesyperus
differ sharply from each other by their appearance, they have very similar male genitalia.