Tarphius (Glabrotarphius) desertaensis, Machado, 2012

Machado, Antonio, 2012, Two new Tarphius species from Macaronesia (Coleoptera, Zopheridae), Journal of Natural History 46 (9 - 10), pp. 637-643 : 637-639

Tarphius (Glabrotarphius) desertaensis n. sp.

( Figure 1 )

Type material

Holotype. Madeiran archipelago ( Portugal), Ilhas Desertas, Deserta Grande, Topo S, 390 m (32 ◦ 30 ′ 05 ′′ N, 16 ◦ 30 ′ 01 ′′ W) one ex 27 June 2008 leg. A. Machado (reg. TFMC/CO-15958 Museo de Ciencias Naturales , Santa Cruz de Tenerife) . Paratypes, six exx same data (in my collection).

Diagnosis

Characterized by its small size (<2.5 mm), uniform brown colour, convex body, pronotum about 1.6 × as wide as long, abdomen subcylindrical, at apex briefly protruding, elytra devoid of nodules, and tegument indistinctly tuberculate with separate small broad setae in rows.

Other small species (<3mm) of Tarphius present in the Madeiran archipelago differ as follows: T. zerchei Gillerfors, 1997 is smaller and has reduced eyes; T. excisus Wollaston, 1857 has a pronotum much wider than twice its length, and T. lowei Wollaston, 1854 bears nodules on the elytra (rufescent on a blackish background).

Description

Length 2.15–2.45, width 0.94–1.12 mm. Tegument brown; appendages slightly lighter.

Head. Greatest width before eyes; supraocular callosity developed and delimited by superficial furrows; anterior margin curved. Surface covered with indistinct granules and separate small setae. Eyes small, less protruding. Antennae slightly shorter than head width; segment 2 longer than 3, segments 4 and 5 subequal, and segments 6 to 8 slightly transverse ( Figure 1B ).

Pronotum transverse, 1.5–1.6 × as wide as long; greatest width at or near middle; sides rounded, not greatly constricted anteriorly than posteriorly; separated tubercles bearing short broad setae fringing lateral margin. Base widely curved distad (except at angles); anterior margin strongly curved. Disc strongly convex, not canaliculated at middle, with a slight declivity towards sides; these moderately flattened. Tegument with diffuse tubercles each bearing a small seta.

Elytra subcylindrical, 1.4–1.5 × as long as wide, slightly wider than pronotum, sides subparallel, widest in posterior half; lateral margin of elytra not visible from above in posterior half (hidden by lateral limbs); apical declivity abrupt and vertical, apex briefly protruding backwards and visible from above. Base oblique laterally; humeral angle obtuse and rounded, margin fringed by small tubercles bearing setae ( Figure 1A ); flattened humeral area very reduced. Dorsal part without nodules; tegument covered by indistinct flat tubercles ordered transversally and along intervals, these with a row of separate small broad setae pointing backwards.

Aedeagus as in Figure 1C . Median lobe blunt apically, as long as parameres; tegmen 1.6 × as long as parameres; ductus ejaculatoris projecting very slightly from tegmen.

Bionomics

All the specimens of the type series were sifted from leaf-litter, dead branches and vegetation (mostly lichens) growing on rocky walls facing West at the upper parts of the islet of Deserta Grande. The species may well be endemic to this little group of islets.

Figures

Figure 1. Tarphius desertaensis n. sp. imago (A), detail of antenna (B) and aedeagus (C).