A new, peculiar genus of Cossoninae (Coleoptera, Curculionidae) from Oman with description of a new species, larva and notes on biology
Author
Hlaváč, Peter
Author
Skuhrovec, Jiří
Author
Pelikán, Jan
text
Zootaxa
2020
2020-04-30
4768
1
129
142
journal article
22450
10.11646/zootaxa.4768.1.8
ddd1be2a-daf6-49fc-a865-b995cbf2f79c
1175-5334
3777916
urn:lsid:zoobank.org:pub:45D87901-3967-43D7-8F9C-E9B0B472F9E1
Omanocossonus
Hlaváč, Skuhrovec & Pelikán
gen. nov.
(
Figs 1
A–B, 2A–B, 3A–E, 4A–H)
Type
species.
Omanocossonus sabulosus
Hlaváč, Skuhrovec & Pelikán
sp. nov.
, gender masculine.
Etymology.
The name is a combination of
Oman
, the country where the genus was discovered, and
Cossonus
, referring to the affinity of the genus to the subfamily
Cossoninae
.
Diagnosis.
Rostrum wide, about as long as wide, not delimited from rest of head capsule, eyes well-defined, lateral, distant from posterior margin of pronotum, funicle composed of seven antennomeres, slightly shorter than scape, scape at base pedunculate, last three antennomeres of antennal club completely fused. Humeri absent, elytra on sides rounded, strongly narrowed to apex. Mesoventrite on the same level as metaventrite, mesoventral process much wider than prosternal process, slightly wider than middle tibiae. Terminal tarsomere shorter than tarsomeres I–III combined, claws free, simple.
Description.
Body stout, reddish-brown, almost completely glabrous, shiny (
Figs 1
A–B); about
2.9–3.5 mm
long.
Head short, about half length of pronotum, rostrum wide, about as long as wide, strongly punctured (
Figs 2
A–B), eyes laterally slightly prominent, temples more than 1.5 times as long as longitudinal diameter of eyes, posterior part of head less densely punctured. Head ventrally shagreened, lacking gula, with gular suture entire on posterior part.
Antennae (
Figs 2A
,
3A
) short, inserted in midlength of rostrum, scape longest, basally pedunculate, funicle about as long as scape, with 7 antennomeres; antennomere II longest, III slightly longer than wide, antennomeres IV–VIII transverse, club compact and semi-spherical, composed of last three fused antennomeres, with dense bunch of short setae.
Pronotum more than twice as long as head, almost as wide as long, maximum width in basal fourth, surface with dense, large uneven punctures, anterior and posterior margin straight, slightly constricted just before anterior margin, with few lateral setae.
Elytra oval in dorsal view, about 1.35 times as wide as pronotum and about 1.45 times as long as wide, with 6 shallow striae, interstriae wide, both striae and interstriae bearing shallow, small punctures. Humeri absent.
Venter. Prosternum and mesoventrite on same level, shagreened, both with few shallow discal punctures, pro- sternum with transverse depression close to densely dentate anterior margin, prosternal process narrow, reaching short anterior mesoventral process, procoxae narrowly separated, posterior mesoventral process wide, slightly con- vex, about as wide as width of mesocoxae, attached to anterior slightly concave metaventral process. Metaventrite slightly wider than mesoventrite, with dense shallow punctures, setose, posterior metaventral process wide, straight, about twice as wide as anterior metaventral process, metaventrite and ventrite 1 with median shallow depression.
Abdomen (
Fig. 3B
) with ventrites 1–2 fused, separation line slightly-defined in middle, both shiny, with few shallow punctures and setae, ventrite 1 slightly longer then 2, together very long, clearly longer than ventrites 3–5, ventrites 3 and 4 very short, ventrite 5 almost twice as long as 3–4 combined, with dense setation on posterior margin.
Legs short and stout, protibiae with strongly prolonged uncus, mucro absent (
Fig. 3C
), mesotibiae with premu- cro, uncus about as long as mucro (
Fig. 3D
), metatibiae strongly expanded at apex, uncus shorter than mucro (
Fig. 3E
); terminal tarsomere (onychium) about as long as tarsomeres II and III combined, claws free, simple.
Male terminalia. Sternite IX (
Fig. 4B
) slightly curved anteriad, basal arms well defined, left distinctly longer than right. Tegmen (
Fig. 4D
) short, manubrium shorter than diameter of tegmen ring, parameres absent. Penis (
Figs 4A, D
) short, slightly curved laterally, about 2.5 times shorter than aedeagal apodemes; endophallus with three welldefined sclerites (
Figs 4A, D
).
Female terminalia. Sternite VIII (
Fig. 4E
) asymmetrical, with long and slender apodeme, anterior bar of apodeme very weakly-defined; basal plate wide, bearing short setae, more strongly sclerotized at base. Ovipositor (
Fig. 4F
) sim- ple, small, elongate, weakly sclerotised, styli parallel-sided, truncate at apex, bearing 4 apical setae. Spermatheca (
Fig. 4H
) simple, with regularly curved corpus, cornu tapered, nodulus round, ramus absent. Rectal loop (
Fig. 4G
) long.
FIGURE 1.
Omanocossonus sabulosus
sp. nov.
, habitus, male, lectotype:
A—
dorsal view,
B—
lateral view. Scale bar: 1 mm.
Sexual dimorphism.
Not apparent.
Differential diagnosis.
Omanocossonus
gen. nov.
belongs to a group of flightless genera of
Cossoninae
that are characterized by having weakly defined humeri and having the sides of the elytra oval. These palaearcic genera were grouped by
Folwaczny (1973)
in three weakly defined tribes (
Dryotribini
,
Neumatorini
and
Onycholipini
). The monogeneric
Neumatorini
should be definitely excluded from this group as the elytra of
Neumatora
Normand, 1920
are clearly parallel-sided, not rounded. Unfortunately, this is also the case for many
Dryotribini
and Onycho- lipini.
Onycholipini
differs from
Dryotribini
by having short rostrum (about as wide as long) while the rostrum is always clearly longer than wide in
Dryotribini
. Due to the rostrum of
Omanocossonus
being as wide as long, the best but only tentative position for
Omanocossonus
is in the tribe
Onycholipini
. At present,
Onycholipini
con- tains 21 genera (
Alonso-Zarazaga & Lyal 1999
), although the reason for this placement is questionable. At least
Hexarthrum
Wollaston, 1860
;
Leipommata
Wollaston, 1857
;
Pselactus
Broun, 1886
;
Pseudopentarthrum
Wollaston, 1873
and
Tarphius
Pascoe, 1885
have the rostrum clearly longer than wide and so they should not be placed into
Onycholipini
. Thus,
Omanocossonus
can be readily separated from these genera.
Omanocossonus
also cannot be confused with genera with parallel-sided, often in cross-section cylindrical body, and which are members of
Onycholipini
:
Beaveriola
Osella, 1983
;
Brachytemnus
Wollaston, 1973
;
Eurycorynes
Wollaston, 1873
;
Hopliturus
Marshall, 1956
;
Miorrhinus
Marshall, 1936
;
Pseudophloeophagus
Wollaston, 1873
;
Pseudostenoscelis
Wollaston, 1877
;
Stenoscelis
Wollaston, 1861
;
Stenoscelodes
Konishi, 1962
;
Stereocorynes
Wollaston, 1873
and
Trichacorynus
Blatchey, 1916
. In fact,
Omanocossonus
mostly resembles the genus
Pentatemnus
Wollaston, 1861
and
Lindbergius
Roudier, 1957
, both actually assigned to
Dryotribini
by
Alonso-Zarazaga & Lyal (1999)
, but the placement of both of these genera within this tribe is also questionable. It seems that the positions of genera in these two tribes are mixed and both tribes should be probably merged together or else other characters to delimit them should be found.
Omanocossonus
is readily separated from
Pentatemnus
by the rostrum being about as long as wide, clearly longer than wide in
Pentatemnus
and from
Lindbergius
, by the glabrous elytra lacking tubercles and the normally developed, dorsally well-visible eyes.