Type material.
Holotype male, pinned, with labels as follows: "Yemen, Soqotra Is., 10 km W HADIBOH/ 23.xi.-11. xii.2003, 10 -70 m [GPS]/ leg. P. Kabátek , ex larve", 12°39'N ; 53°57'E ; "YEMEN-SOQOTRA/ 2003; Expedition: Jan Farkač , Petr Kabátek & David Král“ ; "Host plant: Euphorbia arbuscula" . Allotype female, pinned: the same data as the holotype. Paratypes: 69 males, 70 females: the same data as the holotype; 7 males, 5 females: "Yemen, Soqotra Is., SUQ E/ env. sand dune, 22.XI.2003 , 12°40'02N; 54°03'45E, 20-170 m [GPS]/ leg. P. Kabátek , ex larve"; "YEMEN-SOQOTRA/ 2003; Expedition: Jan Farkač , Petr Kabátek & David Král“ ; "Host plant: Acacia pennivenia ".
Holotype and Allotype deposited in the collection of National Museum in Prague, 147 paratypes in the author’s collection, 2 paratypes in Naturhistorisches Museum, Wien, 2 paratypes in Muséumd’Histoire Naturelle, Genève .
Diagnosis.
Triotemnus socotraensis is morphologically very distinct from all other species of the genus due to the very stout body and morphology of elytra. There is no other known species with such strongly punctate elytral striae and granulato-punctate interstriae. It is also unique by the uniformly dark, nearly black, colour.
Description .
Male. Length 1.41-1.89 mm (1.76 mm in holotype), 2.23-3.28 times longer than wide (2.38 in holotype), short and cylindrical, very stout, colour dark brown to black. Head. Frons broadly concave up to vertex, slightly flattened transversely above the epistoma, matt, concavity shallowly, but very distinctly and rather densely punctured, whole surface including inside and between punctures strongly shagreened, excavation separated from vertex by a well defined transverse costal ridge, which is somehow undulated due minute blunt tubercles, vertex shagreened; vestiture of sparse, short, semi-erect, golden hair-like setae, these becoming more dense and longer around the insertion of antennae. Eyes rather deeply emarginate on anterior margin, their fronto-dorsal margin slightly protuberant above the costal ridge of excavation of frons. Each mandible with a very long sabre-shaped process directed anteriorly and curved inward, length of each of these processes roughly equal to the length of the antenna. Antennae reddish, antennal funicle 3-segmented, antennal club oval, flattened, anterior side clearly marked by two procurved sutures, basal segment corneous, posterior side marked by two obscure rows of setae displaced apically. Pronotum 1.05-1.51 times longer than wide (1.05 in holotype), sub-quadrate, lateral, anterior and posterior margins slightly rounded from dorsal view, widest in the middle of its length, weekly declivous in front, summit not clearly marked, situated approximately in the middle, with a second summit just before the anterior margin, disk matt, of the same appearance as frons, shallowly, but very distinctly and rather densely punctured, punctuation becoming stronger towards pronotal base, granulated between punctures, surface strongly shagreened, impunctate median longitudinal area missing; vestiture of sparse, short semi-erected hair-like setae mixed with two times longer erected hair-like setae, the later becoming more dense and longer towards anterior margin. Elytra 1.31-1.91 times longer than wide (1.32 in holotype), 1.25-1.39 times longer than pronotum (1.26 in holotype), parallel on basal three-fourths, than converging to broadly rounded apical margin; base of elytrae rounded, not armed, sometimes a few blunt tubercles present as continuation of interstrial tubercles; scutellum visible, rather small, flush with elytra; elytral striae slightly impressed on elytral disk, deeply and densely punctured, punctures separated by less than the diameter of a puncture, interstriae narrower than striae, punctated and granulated, elytral suture very slightly elevated on the base of elytral declivity. Elytral declivity regularly rounded, of the same appearance as the elytral disk, except strial punctures and interstrial tubercles slightly larger, apical margin not armed, rounded. Elytral vestiture of semi-erect or erect, short, stout, sparse, uniseriate interstrial hair-like setae on the disk and declivity of elytra, their length is shorter than the distance between strial punctures, these setae becoming up to three times longer laterally and posteriorly. Legs dark brown. Procoxae subcontiguous, prosternal process narrow, sharply pointed, apically curved downward; mesocoxae broadly separated by distance of twice width of scapus, mesoventral process descending, broad and transversely truncated apically; metacoxae separated by similar distance as mesocoxae. Number of tibial socketed teeth on outer lateral margin varying between the specimens and between the right and left side. Protibiae with 4-5 socketed teeth, mesotibiae with 5-6 and metatibiae with 5 socketed teeth.
Female . Length 1.33-1.89 mm (1.74 mm in allotype), 2.31-2.38 times longer than wide (2.35 in allotype). Head similar to male, but mandibulae not armed by tooth-like processes, frons convex, slightly flattened just above the epistoma, semi-matt, sparsely and finely punctate in the middle, punctuation getting very dense near epistoma on flattened area, nearly impunctate on vertex, whole surface shagreened; vestiture of gold, very sparse to missing short hair-like setae on vertex and becoming rather dense and long towards epistoma, anterior side of antennal club marked by two more strongly procurved sutures. Pronotum with lateral margins more narrowly converging anteriorly, punctuation of pronotum less distinct, tuberculation stronger.
Etymology.
Name of the new species is derived from Socotra - the island of its origin.
Biology.
Specimens were collected from wilting shrubs of Euphorbia arbuscula ( Euphorbiaceae ) in Hadiboh and Acacia pennivenia ( Fabaceae ) in Suq, additional specimens were obtained by rearing in the lab. Both host plants are endemic to Socotra. The newly described species is phloeophagous. The gallery system was not studied.
Distribution.
Yemen - Socotra, endemic.
