Eggersanthus Sittichaya & Smith 2020, gen. nov.
Creators: name: Sittichaya, Wisut
name: Smith, Sarah M.
Publisher: name: Zenodo
Year: 2020
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Coleoptera
Curculionidae
Eggersanthus

description: Eggersanthus, gen. nov.
(Fig. 1 A–G)
Type species: Webbia sublaevis Eggers, 1927
Material examined. Holotype, female: USNM, PHILIPPINES, Mindanao, Provinz Surigao, Surigao; Nontypes: females, lowland tropical rain forest of the Ton Nga Chang Wildlife Sanctuary, Songkhla province, Thailand (6°59’32.1”N 100°08’57.8”E) (3, WST).
Diagnosis: Eggersanthus is most similar to Arixyleborus (Figure 2 and Table 1) and can be separated from other xyleborine genera by the following combination of characters: pronotum in dorsal view rectangular (type a in Hulcr et al. 2007), anterior margin weakly concave, without a median row of serrations, corners sharply quadrate, anterolateral corners asperate with 4–5 serrations forming a 90° angle; pronotum in lateral view with disc longer than anterior slope (type 7 in Hulcr et al. 2007); antennal funicle 4-segmented, club obliquely truncate type 2 (Hulcr et al. 2007), approximately circular, as long as wide, segment 1 corneous, nearly encircling anterior face, segment 2 pubescent, visible on anterior face only; elytral declivity with granulate striae and interstriae; protibiae very slender, distinctly triangular, posterior face flat and unarmed; scutellum large, triangular, clearly visible from dorsal view; elytra attenuate; and no mycangial tufts present.
Description: Female. Length 2.05–2.2 mm and 2.73–2.90 times as long as wide (n = 4). Body color light brown to brown, darker in appearance on pronotum anterior slope and elytral declivity.
Head. Mandibular base broad, mandibles short. Epistoma with long yellowish setae arranged in a single row. Frons flat, shagreened, with an indistinct small flat median line; vestiture of fine hairs of variable length. Eye comparatively large, shallowly emarginate at antennal insertion, lower portion distinctly larger than upper. Submentum shallowly impressed, shaped as a very narrow triangle. Antennal scape short and thick; pedicel cup-shaped, longer than funicle; funicle 4-segmented, antennal club type 2 (Hulcr et al. 2007), moderate in size, approximately circular, as long as wide, segment 1 prominent, distinctly corneous, its margin convex, costate, nearly covering posterior face; second segment not sclerotized, soft, visible on anterior face only.
Pronotum. Robust, in dorsal view rectangular (type a in Hulcr et al. 2007), anterior margin weakly concave, without a median row of serrations, corners sharply quadrate, anterolateral corners asperate with 4–5 serrations forming a 90° angle, asperities on anterior slope short, moderately sized and coarse; disc shagreened; basal margin bisinuate; no mycangial tuft; pronotum in lateral view with disc longer than anterior slope (type 7 in Hulcr et al. 2007).
Scutellum. Clearly visible in dorsal view, comparatively large, triangular, flat, flush with elytra, impunctate.
Elytra. 1.53–1.63 times longer than wide; 1.53–1.63 times longer than pronotum, sides parallel from base to apical for three-fourths of length and then becoming gradually attenuate, apex acuminate. Base slightly bisinuate. Disc shining, striae and interstriae uniseriate punctate, striae with long setae, interstriae with minute shallow punctures and a row of shorter setae. Declivity rugose, dull, striae and interstriae granulate; striae uniseriate granulate, granules rhomboidal, very closely arranged; interstriae broader than striae, covered with one or two rows of irregular minute granules.
Legs. Protibiae very slender, distinctly triangular, outer margin straight, widest at apical margin, armed with 4 medium denticles clustered at apical quarter, one or two additional spines may be present on apical half, posterior side flat, finely setose. Procoxae contiguous. Prosternal posterocoxal process flat.
Etymology: Masculine, Eggers + Greek anthos = glory, meaning “glory of Eggers”. The name honors the late Dr. Hans Eggers, a prolific German bark beetle taxonomist who described the type species and has had a significant impact on bark and ambrosia beetle classification.
Distribution: PHILIPPINES, Mindanao; THAILAND, Songkhla province.
Biology: Unknown but probably similar to that of Arixyleborus and Webbia species which are specialized on Dipterocarpaceae and Fagaceae in Asia (Browne 1958, 1961), though Papua New Guinean species are host generalists (Hulcr & Cognato 2013).
description: Published as part of Sittichaya, Wisut & Smith, Sarah M., 2020, Eggersanthus Sittichaya & Smith gen. nov., a new Oriental ambrosia beetle genus (Coleoptera: Curculionidae: Scolytinae: Xyleborini), pp. 282-288 in Zootaxa 4779 (2) on pages 283-284, DOI: 10.11646/zootaxa.4779.2.9, http://zenodo.org/record/3833595