Amasa macarthorum Sittichaya & Smith, 2022

Sittichaya, Wisut & Smith, Sarah M., 2022, New species and new records of Amasa Lea, 1894 ambrosia beetles from Thailand (Coleoptera: Curculionidae: Scolytinae: Xyleborini), Zootaxa 5196 (2), pp. 197-210 : 200-205

Amasa macarthorum Sittichaya & Smith sp. nov.

( Fig. 4 )

http://zoobank.org/ urn:lsid:zoobank.org:act:F6B675A6-F349-4865-B35D-D0E970524B93

Material examined. Holotype, female: THAILAND, Chaiyaphum Province, Phu Khiao Wildlife Sanctuary, 16°23′38.8″N 101°34′07.8″E, Dry-dipterocarp forest with pine subtype, 870 msl., ethanol baited trap, 21.vii.2019, W. Sittichaya, (NHMW) ; Paratypes, female, Nakhon Sri Thammarat Province, Khao Luang National Park, 8°43′08.7″N 99°40′39.2″E, tropical rainforest, ethanol baited trap, 01.vi.2011, Loei Province, Phu Luang Wildlife Sanctuary , 17°16′58.1″N 101°31′10.4″E, 1,460 msl., Hill evergreen forest, ex dry branch, 25.vi.19, (1) (all W. Sittichaya) (2 WSTC), Chaiyaphum Province, Phu Khiao Wildlife Sanctuary, 5.vii.2005, J. Hulcr, S. Dole, ex branch (1 MSUC) .

Diagnosis: 2.90–2.98 mm long; 2.44× as long as wide. This species is distinguished by the pronotum appearing basic (type 2) when viewed dorsally, anterior margin serrate, pronotal anterior slope shagreened with densely spaced, short fine asperities, strial punctures small, shallow and inconspicuous, elytral discal interstriae densely punctate, punctures small and confused, not seriate, declivital face smooth and shining, punctures on declivity large, much larger then on disc.

Similar species: Amasa lini Smith, Beaver & Cognato , A. youlii Smith, Beaver & Cognato.

Description (female). 2.90–3.10 mm long (mean = 2.99 mm; n = 3; pronotal anterior margin to declivital summit 2.58–2.70 mm, mean 2.63 mm; n = 2); 2.27–2.44× as long as wide. Body shining, bicolored: pronotal disc, head, legs, antennae and venter brown to dark brown, anterior slope of pronotum, and elytra, dark reddish brown. Head. Epistoma entire, transverse, with row of hair-like setae. Frons weakly convex to upper level of eyes. Median impression between eyes triangular and short, surface subshiny shagreen with longitudinal asperities. Frons below eyes alutaceous, subshiny, with moderately large longitudinal asperities, asperities rounder, denser and larger above epistoma, increasing in length dorsally and laterally. Eyes deeply emarginate just above antennal insertion, upper part smaller than lower part. Submentum triangular, deeply impressed. Antennal scape regularly thick, shorter than club (5:8). Pedicel as wide as scape, shorter than funicle. Funicle 4-segmented, segment 1 approximately equal in length with pedicel. Club taller than wide (8:6) and flat, type 4; segment 1 corneous, small convex on anterior face, occupying approximately basal 1/5; corneous parts of segment 2 and 3 wide nearly as wide as segment 1; segments 1–3 present on posterior face. Pronotum. 1.04× as long as wide. In dorsal view basic and parallel-sided, type 2, sides parallel in basal 1/2, rounded anteriorly; anterior margin with a row of seven or eight serrations. In lateral view basic, type 0, disc flat, summit at midpoint. Anterior slope shagreened with densely spaced, short fine asperities, becoming lower and more transverse towards summit, bearing long, fine, semi-recumbent hair-like setae. Disc shining, alutaceous, densely minutely punctate, glabrous. Lateral margins sharp obliquely costate. Base transverse, posterior angles narrowly rounded. Elytra. 1.25× as long as wide, 1.25× as long as pronotum. Elytra subshiny, alutaceous. Scutellum small, narrow, linguiform, flush with elytra, flat, shining, its anterior portion extend forwardly beyond elytral base. Base bisinuate, edge carinate, humeral angles rounded, parallel-sided in basal 4/5, then sharply angulate to apex. Disc flat, shining, glabrous; striae and interstriae laterally slightly diverging from base to declivital summit; striae punctate, punctures small, shallow; interstriae flat, finely punctate, punctures 1/3 size of strial punctures, strongly confused. Declivity truncate, face slightly ascending posteriorly, margin sharp carinated; upper portion of face near lateral margin flattened, lower part on the middle strongly elevated and bearing uniseriate, round apical tubercles on middle of interstria 1. Declivital face strongly shining, smooth; three striae present, strial punctures shining, small, moderately deep, larger than on disc; interstriae slightly inflated, very fine inconspicuous punctate, punctures wide separated; each with very fine very short hair-like setae (visible with high magnitude). Posterolateral margin forming a circumdeclivital carina; carina globous without setae. Legs. Procoxae contiguous, prosternal coxal piece flat, inconspicuous. Protibiae slender, broadest at apical 1/3; posterior face inflated, coarsely granulate; apical 1/2 of outer margin with six medium size socketed denticles, their length 1/2 time as long as basal width. Meso- and metatibiae broad, flattened, outer margins evenly rounded with 11 and 12 small socketed denticles, respectively; posterior faces unarmed; anterior faces coarsely granulate.

Etymology: The name honors the John D. and Catherine T. MacArthur Foundation, the primary funding source for the Biodiversity Heritage Library, which “serves to improve research methodology by collaboratively making biodiversity literature openly available to the world”.

Distribution: THAILAND: Chaiyaphum Province, Loei Province, Nakhon Sri Thammarat Province.

Host plants: Unknown.

Figures

FIGURE 4. Amasa macarthorum sp. nov. holotype A) dorsal view; B) lateral view; C) postero-lateral view; D) frons; E) venter and antennae.