Anisandrus triton Sittichaya, Smith & Beaver, 2023

Sittichaya, Wisut, Smith, Sarah M. & Beaver, Roger A., 2023, New species and newly recorded species of Anisandrus Ferrari, 1867 ambrosia beetles from Thailand (Coleoptera, Curculionidae, Scolytinae, Xyleborini), ZooKeys 1182, pp. 289-306 : 289

Anisandrus triton Sittichaya, Smith & Beaver sp. nov.

Fig. 4

Type material.

Holotype: female, Thailand, Kanchanaburi Province, Thong Pha Phum District, Thong Pha Phum National Park, 14°41'40.6"N, 98°23'51.9"E, 940m, low montane forest, ethanol-baited trap, 11.xii.22, W. Sittichaya (MSUC).

Similar species.

Anisandrus auco , A. cryphaloides .

Differential diagnosis.

4.22 mm long; 1.94 × as long as wide. Large, broad, stout species. Elytral disc with a saddle-like, weak impression on middle of disc; declivity longer than disc; interstriae 2 armed with two pairs of spines, backwardly incurved on declivital summit and one additional smaller sized spine on upper portion of declivital face; interstriae 3 armed with a row of 3-5 unequally sized spines and granules; declivital face feebly convex, apex broadly rounded; posterolateral margin rounded, with a short costa near apex. The species is similar to Anisandrus auco , A. cryphaloides , and A. tanaosi . It can be distinguished from them by the following characters ( A. triton given first): greater size (4.2 mm long vs 2.1-3.0 mm) and stouter body (1.94 × longer than wide vs 2.2-2.4 ×; elytral disc with a weak, saddle-like depression vs elytral disc flat; upper margin of the elytral declivity with a pair of backwardly directed, sharply pointed spines vs a pair of minute, pointed granules.

Description.

Female. 4.22 mm long (n = 1); 1.94 × as long as wide. Body black except appendages brown; body densely covered with long, erect, yellowish-brown, hair-like setae. Head: epistoma entire, transverse, with a row of short and sparse, hair-like setae, sparser in the middle and on lateral margins below eyes. Frons with a weak median ridge extending to upper margin of eyes, weakly impressed on each side near epistoma, becoming flattened and weakly convex above, reticulate, subshining, with sparse, large, shallow, punctures, each puncture bearing a shorter, finer, erect hair-like seta than those on epistoma; punctures becoming smaller and shallower towards vertex. Eyes large, feebly emarginate just above antennal insertion; upper part of eyes much smaller than lower part. Submentum transversely long, narrowly triangular, slightly impressed. Antennal scape slender, 1.4 × as long as club. Pedicel as wide as scape, shorter than funicle. Funicle 4-segmented, segment 1 as long as pedicel. Club longer than wide, obliquely truncate, type 1; segment 1 corneous, encircling anterior face; segment 2 narrow, corneous on anterior face only; sutures absent on posterior face. Pronotum: 0.83 × as long as wide. In dorsal view, between type 0 and type 6, sides convex, strongly narrowed anteriorly; anterior margin with a row of seven medium-sized serrations. In lateral view, short and tall, type 3; disc slightly shorter than anterior slope. Anterior slope with moderately dense, large, coarse asperities, becoming lower and more strongly transverse towards summit. Disc convex, moderately shiny with moderately dense, minute, punctures bearing two types of setae: moderately long, erect, hair-like setae and short, semi-recumbent, hair-like setae; some longer, hair-like setae at margins. Base transverse; posterior angles broadly rounded. Mycangial tuft present along basal margin; tuft dense, long, setose, approximately 2 × width of scutellum. Elytra: 1.18 × as long as wide, 1.63 × as long as pronotum. Scutellum small, broad, linguiform, shiny, slightly convex, flush with elytra. Elytral base transverse, edge oblique, humeral angles rounded, parallel-sided in basal ½, then broadly rounded to apex; surface shining. Disc shallowly, transversely impressed; striae not impressed, with medium-sized, shallow punctures separated by the diameter of a puncture; strial setae 1.5 × as long as punctures, semi-recumbent, hair-like; discal interstriae 1 and 3 flat, interstriae 4 and 5 weakly convex; near upper margin of declivity, interstriae 1-5 weakly convex; interstriae biseriate punctate, punctures minute, shallow, each bearing an erect hair-like seta; setae on disc as long as interstrial width, some longer setae present on lateral and apical margins of elytra; punctures on lateral margins and near declivital summit replaced by small granules. Declivity occupying approximately 1/2 elytra, evenly rounded, declivital face convex; striae feebly impressed, strial punctures the same size and depth as those of disc; interstriae feebly convex, 1-3 of equal width, biseriate granulate; setae 2 × width of an interstria, erect, hair-like; declivital interstria 2 armed with two pairs of spines; the larger on declivital summit backwardly hooked, the smaller on upper portion of declivital face pointed; interstria 3 armed by a row of 5 spinulose granules, the upper two pairs slightly backwardly hooked. Posterolateral margin of declivity rounded, with a short costa near apex, unarmed by granules. Legs: procoxae slightly separated; prosternal coxal piece short, inconspicuous. Protibiae obliquely triangular, broadest at apical 1/3; posterior face inflated, unarmed; apical 1/2 of outer margin with six moderately sized socketed denticles, length approximately equal to basal width. Meso- and metatibiae flattened; outer margins evenly rounded each with eight moderately sized socketed denticles.

Male. Unknown.

Etymology.

Ancient Greek, triton is a fish-tailed sea-god, named after a veteran vehicle used in beetle surveys by the senior author.

Distribution.

Thailand (Kanchanaburi Province).

Biology.

Unknown.

Figures

Figure 4. Anisandrus triton sp. nov. holotype female A dorsal view B postero-lateral view C lateral view D frons E antenna.