﻿New species and newly recorded species of Anisandrus Ferrari, 1867 ambrosia beetles from Thailand (Coleoptera, Curculionidae, Scolytinae, Xyleborini)

﻿Abstract Five new species, Anisandrusmontanussp. nov., A.phithakpasp. nov., A.tanaosisp. nov., A.tritonsp. nov., and A.uniseriatussp. nov. are described from Thailand. Anisandruscarinensis (Eggers, 1923) is reported from Thailand for the first time and A.apicalis is removed from the Thai fauna. With the inclusion of the species described and recorded here, the diversity of Anisandrus is increased to 40 species, of which 11 occur in Thailand. A synoptic list and a key to the Anisandrus of Thailand are presented.


Introduction
The ambrosia beetle genus Anisandrus Ferrari, 1867, was erected for Xyleborus dispar (Fabricius, 1792) because of its antennal club and mouth parts which differ from other Xyleborus Eichhoff, 1864 species (Ferrari 1867).Anisandrus currently contains 35 species distributed through the Palearctic region, from Europe to Japan, and through the Oriental region to New Guinea and the Solomon Islands.A single species occurs in Madagascar, but the genus is not known from the African continent.Two species, A. obesus (LeConte, 1868) and A. sayi Hopkins, 1915, are indigenous to the Nearctic region, and two Palearctic species, A. dispar (Fabricius, 1792), and A. maiche (Kurentsov, 1941) have been introduced to and established in the USA (Wood 1977;Rabaglia et al. 2009;Gomez et al. 2018).Anisandrus maiche is also established in Italy and Ukraine (Nikulina et al. 2015;Colombari et al. 2022).In Thailand, six Anisandrus species were previously recorded (Hutacharern and Tubtim 1995;Beaver and Liu 2010;Beaver et al. 2014;Smith et al. 2020), but one species, A. apicalis (Blandford, 1894) must be removed from the fauna following the recognition of closely similar species with which it was previously confused (see below).In the present study, we describe five new species and report one new species from Thailand, increasing the diversity of the Thai fauna to 11 Anisandrus species and that of the genus to 40.We also provide a key and synoptic list of the Anisandrus of Thailand.

Materials and methods
Specimens were collected at 27 study sites in 24 conservation areas across all regions of Thailand as detailed and illustrated by Sittichaya and Smith (2022), with the addition of 10 study sites in the Tanaosi (Tenasserim) mountain range in western Thailand between September and December 2022 using the same collecting methods.Photographs were taken with a Canon 5D digital camera with a Canon MP-E 65 mm macro lens (Canon, Tokyo, Japan) and StackShot-Macrorail (Cognisys, Traverse City, Michigan, USA).The photos were then combined with Helicon Focus v. 6.8.0.(Helicon Soft, Kharkiv, Ukraine) and all photos were improved with Adobe Photoshop CS6 (Adobe Systems, San Jose, California, USA).The antennal and pronotum types and characters follow those proposed by Hulcr et al. (2007) and subsequently elaborated by Smith et al. (2020).Length was measured from pronotal apex to the apex of the declivity, and width was measured at the widest part of the specimen.Pronotal length included the anterior serrations and elytral length was measured from the anterior margin to the apex along the elytral medial suture.Pedicel is excluded from the number of funicle segments.(Hulcr et al 2007;Smith et al. 2020), club taller than wide (except A. achaete wider than tall); procoxae contiguous or narrowly separated; protibiae slender, obliquely or distinctly triangular, outer margin with 5−8 large socketed denticles on distal half, posterior face flat, unarmed, or with a few small granules; mesonotal mycangial tufts present (except A. achaete, A. carinensis (Eggers, 1923), A. paragogus Smith, Beaver & Cognato, 2020, and A. uniseriatus sp. nov.) along the pronotal base either as a small tuft the length of the scutellum and directly opposite it or extending laterally from the scutellum to striae 3 and with elytral base broadly, shallowly emarginated from the scutellum to striae 3; pronotum anterior margin with a row of serrations, pronotum lateral margins obliquely costate (Smith et al. 2020).Some Anisandrus species have a median pair of pronotal serrations larger than the remaining serrations and superficially resemble Cnestus Sampson species.The genera are easily separated by the lateral margin of the pronotum which is costate in Anisandrus and carinate in Cnestus.
Similar species.A. eggersi (Beeson, 1930), A. improbus (Sampson, 1913).Differential diagnosis.2.80-2.92mm long (mean 2.86, n = 4); 2.33-2.43×as long as wide.This species is similar to A. eggersi, but the body is smaller and more elongate, the declivity is less laterally broadened, and the posterolateral margin is not feebly costate.It is also similar to A. improbus but is distinguished by the following characteristics (A.improbus given first): sparse pubescence vs moderate pubescence, body 3.3-3.4mm long vs 2.80-2.92mm long, and body form more elongate, 2.43−2.54×as long as wide, vs stouter, 2.33-2.43×as long as wide.
Etymology.Latin adjective montanus, found on mountains.The species is known only from Doi Inthanon, the highest mountain in Thailand, at 1680-2550 m.
Biology.This species prefers montane forest.
Remarks.Three of the paratypes listed above were previously reported as A. apicalis by Beaver et al. (2014).
Differential diagnosis.2.88-3.02mm long (mean 2.96 mm, n = 4); 2.06-2.17×as long as wide.Stout species; elytral disc saddle-like, bearing a pair of small spines on interstriae 2. Declivity broad; declivital face with striae 1 and 2 weakly impressed; interstriae 1 and 3 slightly elevated; posterolateral margin rounded, costate only near apex.The species is similar to A. apicalis, A. congruens, and A. cristatus.Anisandrus congruens and A. cristatus are distinguished by the presence on declivital interstriae 3 of a row of 5-7 regularly spaced, backwardly directed, sharply pointed spines; in A. phithakpa and A. apicalis these are reduced to small granules.Anisandrus phithakpa is distinguished from A. apicalis by the following characters (A.phithakpa given first): declivital interstriae with a pair of minute, pointed granules on interstriae 1, and an equally sized pair on interstriae 2 and 3 vs no granules on interstriae 1, and interstriae 2 with a pair of small, backwardly directed, sharply pointed teeth which are considerably larger than the pointed granules on interstriae 3.
Male.Unknown.Etymology.Thai (พิ ทั กษ์ ป่ า) "Phithakpa", forest rangers.The species name indicates our deep appreciation for Thai forest rangers for their hard and selfless work to protect conservation areas in Thailand.Noun in apposition.
Remarks.The paler body colors (brown) of the holotype and some paratypes suggest that they are teneral.One paratype has a consistently dark-brown body with pale appendages.Differential diagnosis.2.31-2.70mm long (mean 2.5; n = 2); 2.20-2.25×as long as wide (mean = 2.23; n = 2).Small and stout species.Pronotal anterior margin slightly angularly projecting; elytral disc convex, without a saddle-like impression, declivital summit armed with a pair of minute, spinulose granules on interstriae 2, declivital face feebly convex, unarmed.Posterolateral margin rounded, costate only near apex.The species is similar to A. auco and A. cryphaloides.It can be distinguished from A. auco by the following characters (A.tanaosi given first): smaller size (2.3-2.7 mm long vs 2.9-3.0 mm); anterior margin of pronotum with seven moderately sized asperities vs four large coarse asperities; more steeply sloping elytral declivity occupying 3/8 of elytral length vs more gently sloping occupying 3/5 of length; dark-brown to black body vs light brown to reddish brown.It can be distinguished from A. cryphaloides by the following characters (A.tanaosi given first): pronotum in dorsal view type 0, anterior margin only slightly projecting, with asperities of equal size vs pronotum more strongly conical, type 6, median pair of asperities larger than lateral pairs.Description.Female.2.31-2.70mm long (mean 2.5; n = 2); 2.20-2.25×as long as wide (mean 2.23; n = 2).Body dark brown to black, head and prothorax dark brown, elytra and venter black, appendages yellowish brown.Antennae and legs light brown.Body densely covered with greyish-brown setae.Head: epistoma entire, transverse, with a row of short hair-like setae, setae sparse.Frons feebly convex to upper level of eyes, weakly reticulate, rugulose-punctate, some rugulosities forming longitudinal lines; each puncture with a moderately long, fine, hair-like setae; a weak, impunctate median ridge extends to upper level of eyes.Eyes feebly emarginate just above antennal insertion, upper part slightly smaller than lower part.Submentum triangular, small, slightly impressed.Antennal scape regularly thick, short, 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 concave, soft and narrow; sutures absent on posterior face.Pronotum: 0.90× as long as wide.In dorsal view, type 0, feebly conical anteriorly, sides convex; anterior margin with a row of seven small, slightly protruding serrations, equal in size to those on anterior slope.In lateral view type 3, short and tall; disc as long as anterior slope, summit at midpoint.Anterior slope with moderately densely spaced, large coarse asperities, becoming lower and more strongly transverse towards summit.Disc alutaceous, subshining with moderately dense, minute granulate punctures, each bearing a short, semi-recumbent, hair-like seta, some longer hair-like setae at margins.Lateral margins obliquely costate.Base transverse, posterior angles angularly rounded.Mycangial tuft present along basal margin, tuft moderately setose, approximately the width of scutellum.Elytra: 1.22× as long as wide, 1.42× as long as pronotum.Scutellum broad, large, linguiform, flush with elytra, flat, shiny.Elytral base transverse, edge oblique, humeral angles rounded, parallel-sided in basal 2/3, then broadly rounded to apex.Disc subshiny, broadly convex; striae not impressed, with small, shallow, setose punctures separated by 1.5-2× diameters of a puncture, setae 3× as long as diameter of punctures, recumbent, hair-like; interstriae flat; punctures strongly confused, without granules, setose; setae short, as long as strial setae, erect hair-like.Declivity occupying approximately 3/8 elytra; summit with a pair of spinulose granules on interstriae 2; declivital face feebly convex above, flattened below from interstriae 1-3; striae weakly impressed; strial punctures somewhat larger and deeper than those of disc; interstriae sparsely uniseriate punctate, setae 2× width of an interstria, erect, hair-like.Posterolateral margin rounded, unarmed by granules, costate only close to apex.Legs: procoxae contiguous; prosternal coxal piece short, inconspicuous.Protibiae obliquely triangular, broadest at apical 1/3; posterior face minutely granulate; apical 1/3 of outer margin with six small, socketed denticles, their length as long as basal width.Meso-and metatibiae flattened; outer margins evenly rounded with eight large, socketed denticles.

Anisandrus tanaosi
Male.Unknown.Etymology.Tanaosi (ตะนาวศรี ), Thai name of the Tenasserim mountain range, in reference to the collection locality of the holotype.Noun in apposition.
Distribution.Thailand (Kanchanaburi and Phetchaburi provinces).Biology.Unknown.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.

Anisandrus triton
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.

Anisandrus uniseriatus
This species is closely related to A. carinensis but is distinguished by the following characteristics (A.uniseriatus given first): discal interstria uniseriate granulate-punctate vs biseriate granulate-punctate; angularly rounded apex vs broadly rounded elytral apex.
Male.Unknown.Etymology.Latin uniseriatus: uni-meaning one; series meaning row, in reference to a single row of interstrial setae.

Correction to faunal list for Thailand
Anisandrus apicalis (Blandford, 1894) Notes.Seven specimens were recorded from Chiang Mai province under this name by Beaver et al. (2014).Three of these specimens are now included in the closely similar species, A. montanus sp.nov.(see above).The other four specimens belong to A. cristatus, which was considered a synonym of A. apicalis at the time of Beaver et al.'s publication.It was reinstated as a distinct species by Smith et al. (2020).We know of no specimens of A. apicalis from Thailand, and the species must be removed from the faunal list.

Discussion
Anisandrus has recently been the focus of intense study, with 18 species described since 2020, including those described here (Smith et al. 2020(Smith et al. , 2022)).The genus is diverse in montane forest habitats in Southeast Asia, and Thailand in particular (Table 1).There is no doubt that additional species await discovery in unsampled mountain ranges throughout Southeast Asia.

Figure 1 .
Figure 1.Anisandrus montanus sp.nov.holotype female A dorsal view B postero-lateral view C lateral view D frons E declivital face.

Figure 2 .
Figure 2. Anisandrus phithakpa sp.nov.holotype female A dorsal view B postero-lateral view C lateral view D frons E antenna.

Figure 3 .
Figure 3. Anisandrus tanaosi sp.nov.holotype female A dorsal view B postero-lateral view C lateral view D frons E antenna.

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

Figure 5 .
Figure 5. Anisandrus uniseriatus sp.nov.holotype female A dorsal view B lateral view C postero-lateral view D frons E venter and antennae F declivital face.

Table 1 .
Synoptic list and habitat types of the Anisandrus fauna of Thailand.References are to records of the species in Thailand.Thai distribution follows that ofSittichaya and Smith (2022)which lists the following abbreviations: C = Central; N = North; NE = Northeast; S = South.