Premnobius assiduus (Schedl) Atkinson & Petrov & Flechtmann, 2018

Atkinson, Thomas H., Petrov, Alexander V. & Flechtmann, Carlos A. H., 2018, New records and combinations in Neotropical Premnobius Eichhoff (Coleoptera: Curculionidae: Scolytinae: Ipini) with an illustrated key to New World species, Insecta Mundi 658, pp. 1-11 : 2-3

Premnobius assiduus (Schedl) new combination

( Fig. 2 )

Xyleborus assiduus Schedl 1961: 228 .

Coptoborus assiduus (Schedl) . Wood and Bright 1992: 662. Combination.

Gnathotrupes assiduus (Schedl) Wood 2007: 671 . Combination.

The head of the unique paratype of this species is hidden ( Fig. 2C ) and previous treatments did not contain detailed information on the structure of the head ( Schedl 1961; Wood 2007). We redescribe P. assiduus on the basis of the paratype and specimens from Peru and Brazil.

Material examined. Paratype ( NMW): VENEZUELA: Amazonas, Mt. Diuda , 4-XI-1928 (female) ; BRAZIL: Amapá: Tartarugalzinho, Comunidade Entre Rios, Retiro Paraíba, 51° 18′ 2.4″ W 1° 7′ 59.6″ N, 27-V-2015, ethanol-baited flight intercept trap at 22 m height, rain forest fragment, W.R. Silva ( MEFEIS, 1) ; FRENCH GUIANA: Camopi: Mont Itoupé, Parc amazonien de Guyane , terra firme ombrophilous forest, 53° 05′ 44″ W 3° 1′ 23″ N, 570 m a.s.l., unbaited window trap, S. Brûlé ( MEFEIS, 1) ; PERU: Junín: 15 km NW of Rio Venado vill., 1100 m a.s.l., 74°46′7.0″ 11°11′35.2″S, 3.X.2014, window trap, A.V. Petrov ( APP, 10) .

Redescription. Female: 1.80–2.25 mm long, 3.6–4.4 times as long as wide. Body reddish-brown to brown, shining.

Head reddish-brown dull, frons convex, surface reticulate, punctured by sparse small rounded punctures, vestiture sparse on central part and more abounded in lateral sides and epistomal process. Eyes weakly emarginate, large, coarsely faceted. Antennae reddish brown, scape as long as club, club round, strongly flattened, with light short setae, sutures strongly procurved.

Pronotum reddish-brown elongate, cylindrical, 1.70–1.75 times as long as wide; sides straight and parallel on more than basal two-thirds, lateral margins curved ventrad in antero lateral area, anterior margin serrate, shallowly subemarginate in median area; disc of pronotum smooth, weakly shining, punctures small to minute, not close, anterior slope obscure, asperate on anterior third. Surface covered by erect brown setae. Scutellum small dark brown, triangular.

Elytra brown, 2.1 times as long as wide, 1.1–1.3 times as long as pronotum; lateral margins straight and parallel on more than basal two-thirds, anterior margin evenly rounded to apex. Disc smooth, striae straight, strial punctures very small, widely divided by distance of 4–5× the diameter of a puncture, interstriae flat, punctures of interstriae equal striae, each interstriae with a row of erect setae. Decliv- ity broadly, deeply concave with a subacute crest on apical half, occupying 40 percent of elytra length; tubercle at base of interstriae 1 very small, on interstriae 3 there is a digitate spine on the lateral crest, slightly inclined towards the median line; a third subquadrate tubercle is located near the apex of the declivity, twice as long as its basal width, not displaced mesad; on the lateral crest there are very small tubercles between the first, second and third spines; face of excavated area smooth, shining, punctures small, most poorly defined. Vestiture in and near declivity longer and more abundant than that of disc. Metasternum and metepisternum reddish brown with short brown setae. Abdomen reddish brown, ventrites bearing erect short brown setae. Legs reddish-brown, unicolored, covered by short yellowishbrown hairs.

Male: Unknown.

Notes. Schedl (1961) described the female of this species in the genus Xyleborus Eichhoff, 1864 . Wood and Bright (1992) treated in in Coptoborus Hopkins 1915 in their world catalog. Later Wood transferred this species from Xyleborus to the genus Gnathotrupes ( Wood, 2007) . In his description of G. assiduus he mistakenly treated the female as a male. Wood also pointed out that the holotype is not at the California Academy of Sciences as indicated by Schedl and that the “ paratype ” may in fact be the “ holotype ”. This “ paratype ” was examined by Atkinson and Petrov.

Figures

Figure 2. Premnobius assiduus (Schedl), female paratype. A) Dorsal view. B) Lateral view. C) Frontal view. D) Declivity. Photos by T.H. Atkinson.