Termitotrox cupido Maruyama

Maruyama, Munetoshi, 2012, Termitotrox cupido sp. n. (Coleoptera, Scarabaeidae), a new termitophilous scarab species from the Indo-Chinese subregion, associated with Hypotermes termites, ZooKeys 254, pp. 89-97 : 91-95

Termitotrox cupido Maruyama sp. n.

Type materials.

Holotype female, north of Preah Khan, Siem Reap, Cambodia, 19 VIII 2012, M. Maruyama (KUM). Paratypes, 6 males, 10 females, same data as holotype (KUM, NHM); 4 males, 1 females, 3 unsexed, same data but 21 VIII 2012 (CMN, KUM, UNSM).

Etymology.

Cupido is the god of desire and love in Roman mythology and is often illustrated as a small, winged boy. The new species is named in reference to the wing-shaped trichomes on the elytra and the remarkably small body size. Noun in apposition.

Diagnosis.

This species is probably related to Termitotrox minutus (Arrow, 1920) because of its small body size and shape of elytra but easily distinguished from it by the spherical elytra, the presence of the trichomes on the elytra and the smaller body.

Description of holotype female.

General colour uniformly reddish brown, slightly matt; length 1.21 mm. Head. Surface generally evenly convex, with only a slight callosity at clypeofrontal transition. Lateral margin of head entirely, finely marginate. Clypeal outline evenly rounded over entire length. Clypeofrons reddish brown, glabrous, distinctly, moderately punctate; vertex with deep groove medially, and 6 or 7 pairs of sharply defined, elongate primary punctures. Clypeofrontal border at (vague) suture straight; genal tip obtusely angular (in dorsal view); genal surface depressed. Antennal club yellowish brown. Prothorax. Prothorax reddish brown, narrower than elytra, sides (in dorsal view) evenly rounded over anterior half. Emargination at center apex not margined, anterolateral lobe rounded, edge slightly projecting downward (forming side of anterolateral propectoral cavity). Pronotal sides steeply declivous. Posterolateral section of pronotum rounded. Basolateral areas concave, with 1 feeble ridge around base; asymmetrical, left part with a tubercule near base. Apical lobe asymmetrical, with right side near apex roundly emarginate. Pronotal surface glabrous. Costae densely punctate, broader intercostal sulci with distinct, longitudinal wrinkles. Discal depression deep; surface, apart from some local micropunctation, smooth. Pronotal pattern of longitudinal costae as follows: Median costa indistinct around apical 1/5; basomedian section narrow, surface deplanate, shallowly concave. Central depression posterolaterally delimited by depressed area of paramedian costa. Paramedian costa anteriorly broad, distinct, continuing to about half of pronotal length. Sublateral costa narrow, distinct, tapering posteriad to about half of pronotal length, reaching paramedian costa. Lateral costa anteriorly broad, distinct, extending from anterolateral lobe caudad, tapering to base of pronotum. Marginal costa posteriorly broad, ending at depressed basolateral area. Elytra.Semi-spherical, reddish brown, matt, with 6 interstrial costae and intervening striae, and with trichomes at base of costae 2-6 to form wing-shaped patches. Humeral and apical elytral umbones absent; apicosutural edge nearly rectangular, slightly protruding. Epipleuron wide. Elytral striae distinct, deeply impressed, with transverse, weak costae from base to apex to form quadrate cells; striae 1 and 2 reaching basal half. Discal interstrial costae broadly trapezoidal (in cross-section), surface with dense, scattered punctures. Elytral pattern of interstrial costae as follows: costa 1 (next to suture) narrow, shiny, almost rectilinear; costa 2 shiny, tapering in front, stopping at basal half. Costa 3 complete, slightly narrowed at middle. Costae 4-6 complete, strongly developed, Costa 7, 8 and 9 apparently fused together. Anterolateral part of propectus deeply excavate. Preprosternal apophysis distinct, with several setae. Remainder of propectus glabrous, dark reddish brown. Posterolateral area of propectus with some ridges and grooves. Postprosternal surface with small, shallow, median impression. Transverse mesometasternal groove between posterior edges of mesocoxae distinct. Mesothorax. Mesosternum with a pair of identical, question-mark shaped grooves bordering the mesocoxae; mesosternal surface reddish brown, glabrous, flattened; anterior surface densely micropunctate. Metathorax. Metasternum evenly convex, glabrous, and with fine perimarginal groove all around; reddish brown, infuscate laterally. Abdomen. Venter with 5 visible sternites, all reddish brown, matt, without grooves, sparsely micropunctate. Pygidium reddish brown, glabrous, base broadly margined; surface generally convex; surface lacking distinct microsculpture, sparsely micropunctate. Legs. Procoxa protuberant. Profemur brown, underside glabrous, sparsely micropunctate; outline broadly ellip tic, emarginate distally. Protibia pale brown, broad, with short setae, microsculpture weak; shape strongly complanate, with 2 external denticles, no basal serration; apex straight, transverse, with distinct apico-internal spine; internal side strongly dilated from slender base. Protarsus twice longer than width of tibial apex, slender, yellowish; segment 1 inserted in fine groove, as long as segments 2-4 combined. Mesocoxae reddish brown, widely separated, slightly divergent anteriad. Mesofemora brown, broadly elliptic in outline, distally emarginate, surface moderately micropunctate, glabrous. Mesotibiae reddish brown, with several setae, broad, dilated near base, nearly parallel-sided from basal half to apex, edges entire; tibial apex deeply emarginate, with pair of acuminate apico-internal spurs, external one long, slightly curved, internal one short, straight; upper side of mesotibiae with fine longitudinal ridge near outer edge, underside with fine sinuate ridge from base to apico-internal section; with long setae around apical 2/5. Metatibiae similar to mesotibiae, but gently dilated apicad, with apex shallowly emarginate. Meso- and metatarsi brown, compacted-complanate, segments 1-4 short. Length of inner apical spur of metatibia 1/4 of metatibia, reaching base of tarsal segment 5.

Male.

Aedeagus (Figs 4, 5) large, half as long as body length; paramere half as long as phallobase, gently narrowed apicad, curved near truncate apex.

Variations.

Apical lobe of pronotum variable in shape, sometimes symmetrical, gently rounded at apex. Costa 7 of elytra sometimes indistinct.

Measurements in mm.

Body length 1.13-1.22; maximum width of head 0.48-0.52; median dorsal length of pronotum 0.47-0.51, maximum width 0.54-0.59, sutural length of elytron 0.50-0.54, maximum width 0.62-0.67.

Symbiotic host.

Hypotermes makhamensis (determined by Dr. Yoko Takematsu).

Remarks.

No significant sexual dimorphism is detected. Male aedeagus is large compared with its body size. Female ovary contained a single huge egg occupying the greater part of the abdomen and metathorax (Fig. 6).