Fraudatrix, Cognato & Smith & Beaver, 2020

Cognato, Anthony I., Smith, Sarah M. & Beaver, Roger A., 2020, Two new genera of Oriental xyleborine ambrosia beetles (Coleoptera, Curculionidae: Scolytinae), Zootaxa 4722 (6), pp. 540-554 : 544-545

Fraudatrix , gen. n.

( Figs 3–18 )

Type species. Fraudatrix melas ( Eggers, 1927) .

Description. Female. Length 1.75–2.50 mm and 2.86–3.33 times as long as wide. Body sparsely setose; color light to dark brown; legs and antennae yellow brown to brown. Appearing very slender, elytra attenuate. Mycangial tufts absent.

Head. Epistoma entire, transverse, lined with a row of hair-like setae. Frons slightly convex from epistoma to upper level of eyes; surface shagreened, dull, punctate; punctures above epistoma small, fine, shallow, punctures larger, deeper on frons. Eyes moderately emarginate above level of antennal insertion, upper portion of eyes smaller than lower part. Submentum slightly impressed below genae, narrowly triangular. Scape short and thick or long and slender, about as long as club. Antennal funicle two-segmented, segments equal in size. Pedicle longer than funicle. Club obliquely truncate, approximately circular; segment 1 corneous, transverse on anterior face, nearly covering all of posterior face; segment 2 slightly procurved, corneous, visible on anterior side of club (type 2, Hulcr et al. 2007).

Pronotum. 1.06–1.5 times as long as wide. Pronotum from lateral view prolonged posteriorly (type 8; Hulcr et al. 2007). In dorsal view more or less elongate, parallel-sided (types 8 or 9; Hulcr et al. 2007), with or without a row of serrations on rounded or subquadrate anterior margin. Surface alutaceous, anterior half finely asperate, asperities close, arranged in concentric arcs from midpoint of pronotum to anterior and anterolateral areas; disc finely and evenly punctate. Lateral margins rounded without a carina. Base transverse.

Elytra. 1.61–2.14 times as long as wide. Elytral base transverse, margin oblique; humeral angles rounded. Scutellum small, triangular, flat, flush with elytra. Sides straight from base to apical half of declivity; attenuate beginning at apical third, apex acute. Disc longer than declivity. Disc smooth, shining, finely punctate; interstrial punctures seriate, each puncture bearing a single erect, fine, golden, hair-like seta (may be abraded); interstriae two times width of striae. Interstriae parallel along their length. Declivital interstriae impunctate, granulate. Posterolateral margins rounded, costa absent.

Legs. Procoxae contiguous, prosternal posterocoxal piece conical, slightly inflated. Protibiae obliquely triangular, broadest at apical third, posterior face flat, unarmed; 5 or 6 large denticles present on outer margin of apical third. Meso- and metatibiae obliquely triangular, flattened, posterior face unarmed.

Diagnosis. Fraudatrix can be distinguished from all other Xyleborini genera by the following combination of characters: antennal funicle two-segmented, antennal club type 2 ( Hulcr et al. 2007) with one suture visible on the posterior face, protibia obliquely triangular with 6 or fewer denticles on outer margin, posterior face flattened and unarmed, elytra with first and second interstriae parallel, scutellum small, flush with elytral surface, mycangial tufts absent, elytra attenuate and pronotal disc longer than anterior slope.

Fraudatrix most closely resembles Cryptoxyleborus with which it shares an attenuate appearance and small size. It can be distinguished from Cryptoxyleborus by the following diagnostic characters ( Fraudatrix given first). Scutellum visible vs scutellum not apparent, antennal club obliquely truncate and type 2 ( Hulcr et al. 2007) vs flattened and type 4, antennal funicle two segmented vs three or four segmented, no more than one suture visible on the posterior face vs three sutures visible.

Etymology. F. fraudatrix (L.) = cheater, liar. In reference to its confusing similarity to Cryptoxyleborus .

Remarks. Fraudatrix was recovered as sister to Stictodex ( Figure 2 ) and they share a type 2 antennal club, two-segmented funicle and obliquely triangular protibia. Stictodex is easily distinguished from Fraudatrix by the following combination of characters: larger size and stouter form (2.40–3.30 mm long; 2.54–2.89 times as long as wide), antennal club very broad, protibiae with 6–8 denticles on outer margin and inflated and granulate on posterior face, elytra with first and second interstriae divergent, broadest at elytral summit, and declivity truncate or broadly rounded.

Figures

FIGURE 2. Details of taxa highlighted in Fig.1. New genera are highlighted and numbers at nodes indicate specific posterior probabilities.

FIGURES 3–18. Lateral, dorsal, posterior oblique and anterior view of Fraudatrix cuneiformis (3–6), F. melas (7–10), F. pileatula (11–14), F. simplex (15–18).