EPITRAGOSOMA ARENARIA, A New Genus and Species from Texas (Coleoptera: Tenebrionidae)
Author
Brown, Kirby W.
P. O. Box 1842 Paradise, CA 95967, U. S. A.
Author
Triplehorn, Charles A.
Museum of Biological Diversity The Ohio State University 1315 Kinnear Road Columbus, OH 43212 1192, U. S. A.
text
The Coleopterists Bulletin
2001
2001-12-31
55
4
515
521
http://dx.doi.org/10.1649/0010-065x(2001)055[0515:eaanga]2.0.co;2
journal article
304901
10.1649/0010-065X(2001)055[0515:EAANGA]2.0.CO;2
0647875f-6005-4b9f-9388-2318633c573f
1938-4394
10102874
Epitragosoma
Brown and Triplehorn
,
new genus
Figs. 1–8
Description.
Body (
Fig. 1
) elongateelliptical, convex, clothed with short but conspicuous pubescence.
Head:
(
Fig. 5
) convex; epistoma with median lobe prolonged, moderately acute; lateral lobes obtusely rounded, not prominent. Ventral postgenal process prolonged, narrow, sharp and slightly everted. Eyes large, weakly convex and not protruding, coarsely faceted; supraorbital carina absent to extremely weak. Maxillary palpus with apical segment securiform. Antenna (
Fig. 6
) not reaching hind margin of pronotum when extended caudad, basal six segments cylindrical with third and fourth segments longest and subequal, width onehalf length, segments 7–10 somewhat flattened, subequal in length but each slightly broader than preceding segment, each with a tomentose sensory area, eleventh segment twothirds as broad as tenth, rounded apically with apical half occupied with a tomentose sensory area.
Pronotum:
convex, lateral margin rounded, lateral marginal bead scarcely defined and not reaching posterior angle; lateral margin arcuate in dorsal view, widest at middle or at hind angles; apical and basal angles acute; apical margin broadly and shallowly concave; basal margin strongly bisinuate.
Elytra:
fused along suture, convex, broadly oval; pseudopleural crest faintly carinate from apex to humeri, interval narrow at apex, gradually widening towards humeri.
Metathoracic wings:
(
Fig. 8
) reduced and nonfunctional, venation vestigial.
Prosternal
process
:
(
Fig. 4
) horizontally produced behind coxae.
Mesosternum:
distinctly but not deeply excavate.
Metasternum:
short, strongly bifurcate posteriorly.
Legs:
stout; profemur weakly expanded apically and not acute; protarsus and mesotarsus with dense pads of golden setae on plantar surfaces of basal four segments, with occasional coarse, stout setae; metatarsus (
Fig. 7
) with pads more poorly developed and stout setae more prominent.
Abdominal tergum 7
of female (
Fig. 2
) highly modified, sharply bifurcate with a deep central sinus; of male (
Fig. 3
) weakly bifurcate with a shallow V shaped sinus.
Abdominal tergum 8
of female trapezoidal, wider apically; of male normal lunate in shape.
Fig. 1.
Epitragosoma arenaria
dorsal habitus, female.
Figs. 2–3.
Epitragosoma arenaria
.
2)
apical abdominal tergites, female;
3)
apical abdominal tergites, male.
Etymology.
The name of this genus refers to its resemblance to
Epitragopsis
Casey.
Type
species.
Epitragosoma arenaria Brown and Triplehorn
,
new species
.
Comparison.
This new genus resembles
Lobometopon
Casey
and keys to that genus in Arnett 1960 (it is included in Arnett and Thomas 2001). It differs in the supraorbital carina usually totally absent, third antennal segment subequal to fourth (third much longer than fourth in
Lobometopon
), weak to absent lateral marginal ridge on pronotum almost never reaching posterior angles, and brachypterous wings with fused elytra and short metasternum. Only two other genera of
Epitragini
are brachypterous,
Conoecus
Horn
and
Tydeolus
Champion. Both
have the pronotum widest anterior to the midpoint.
Conoecus
has a deflexed prosternal process, convex rather than excavate mesosternum, and rounded posterior pronotal angles.
Tydeolus
known from one species in
Mexico
has a flattened rather than convex head.
Epitragosoma
superficially resembles
Epitragopsis
Casey
which has a weak prosternal process, weakly excavated mesosternum, and more protruding eyes.
The structure of the seventh tergite (
Figs. 2, 3
) is a remarkable and previously overlooked character in
Epitragini
. It is sexually dimorphic in many genera and more highly modified in females than in males. The following discussion pertains to females. The seventh tergite in
Cyrtomius
Casey
,
Bothrotes
Casey
and most
Pechalius
Casey
has an apical cavity with a central projection. In
Epitragosoma
,
Lobometopon
,
Pechalius dentiger
(Horn)
and
Metopoloba
Casey
the apical cavity lacks a central projection. In
Lobometopon
,
and
Epitragosoma
the cavity is deep and located between two pronounced projections that in
Epitragosoma
are sharp and narrow. The seventh tergite is only weakly emarginate in
Schoenicus
LeConte
and is unmodified in
Epitragodes
Casey.