Hylastini

Mercado-Vélez, Javier E. & Negrón, José F., 2014, Revision of the new world species of Hylurgops LeConte, 1876 with the description of a new genus in the Hylastini (Coleoptera: Scolytinae) and comments on some Palearctic species, Zootaxa 3785 (3), pp. 301-342 : 308

Key to the world genera in the Hylastini

1 Procoxae widely separated; elytral scale-like setae absent; elytral sides broadening posteriorly....... Scierus LeConte, 1876

- Procoxae subcontiguous; elytral scale-like setae present; elytral sides nearly parallel............................... 2

2 Surface of elytral disc densely covered by cup-shaped setae; odd numbered interstriae distinctly costate, especially at declivity; pronotal disc surface between large punctures abundantly, minutely punctate ( Fig. 4 a); anterior margin of mesoventrite pointed, distinctly extending anteriorly ( Fig. 2 a)........................................ Pachysquamus new genus

- Surface of elytral disc sparsely or densely covered by recumbent, hair-like setae; odd numbered interstriae evenly convex; pronotal disc surface between large punctures impunctate or with medium-sized punctures; anterior margin of mesoventrite slightly rounded or straight, extending anteriorly slightly or not ( Figs. 2 b, c)....................................... 3

3 Third tarsal segment 1.3–1.7× width of second, fifth broadening apically ( Fig. 1 a); pronotal disc with equal or greater number of smaller than larger punctures ( Fig. 4 c); prothorax averaging as long as wide (0.9–1.1); mid-frontal transverse impression usually distinct, without inflated area below ( Fig. 5 a)..................................... Hylurgops LeConte, 1876

- Third tarsal segment 1.0–1.1× width of second, fifth not broadening apically ( Fig.1 b); pronotal disc lacking or with lesser number of smaller than larger punctures ( Fig. 4 b); prothorax averaging 1.2× longer than wide [1.0 (in H. salebrosus ) to 1.3×]; mid-frontal transverse impression absent or indistinct, if present, inflated area below ( Fig. 5 b)...... Hylastes Erichson, 1836

Figures

FIGURE 1. Tarsal characters distinguishing Hylurgops from Hylastes: a) third tarsal segment broader than the second, the fifth tarsal segment broadening apically (Hylurgops longipennis), b) second and third tarsal segments equally broad, fifth not broadening apically (Hylastes mexicanus).

FIGURE 2. Anterior margin of mesoventrite in the Hylastini: a) distinctly pointed (Pachysquamus subcostulatus), b) slightly rounded and sub-inflated (Hylurgops planirostris), c) truncate, margin straight (Hylastes salebrosus).

FIGURE 4. Surfaces between larger punctures in the pronotum: a) densely, minutely punctate (Pachysquamus subcostulatus), b) not punctate (Scierus and Hylastes), c) with smaller punctures about half the size of larger (Hylurgops).

FIGURE 5. Depth of the mid-frontal impression of Hylurgops and Hylastes: a) deep and distinct (Hylurgops rugipennis), b) indistinct or absent (Hylastes mexicanus).