Premnobius

Atkinson, Thomas H., Flechtmann, Carlos A. H. & Petrov, Alexander V., 2023, Synopsis of the Neotropical Premnobiina (Coleoptera: Curculonidae: Scolytinae Ipini) with descriptions of new species, new synonymy and keys to species, Zootaxa 5249 (1), pp. 69-91 : 73

Key to American species of Premnobius (females only)

The following key will distinguish females of all species of Premnobius known from the Americas, both native and exotic.

1 Declivity with a pair of quadrate spines on lower lateral margins, their height subequal to width at base; spines on lateral margins often blunt or digitate ( Fig. 4 A–H )................................................................ 2

- Declivity without pair of quadrate spines on lower margins; all granules or spines on lateral margins acutely pointed or digitate ( Fig. 5 A–F )......................................................................................... 5

2 Pronotum not elongate, length 1/4 of body length; quadrate elevation near middle of declivity in lateral view ( Fig. 4 A,B,E,F ) ................................................................................................... 3

- Pronotum elongate, length 1/3 of body length; quadrate elevations on posterior 1/3 of declivity in lateral view ( Figs. 4 C,D, G–H )............................................................................................... 4

3 Quadrate elevation thickened basally, displaced medially from posterolateral crest; prominent, acute granules at base of declivity on interstriae 2 and 4 ( Fig. 4 A,B )......................................................... flechtmanni (Wood)

- Quadrate elevation not thickened, on posterolateral crest, granules at base of declivity inconspicuous ( Fig. 4 E,F )............................................................................................ neoadjunctus (Schedl)

4 Acute denticle near base of declivity on interstria 3 short, displaced medially from declivital crest; length 3 mm ( Fig. 4 C,D )......................................................................... perezdelacrucei Petrov & Atkinson

- Acute denticle near base of declivity on interstria 3 digitate, nearly as long as quadrate process, on declivital crest; length 2 mm Fig. 4 G,H )............................................................................. assiduus (Schedl)

5 Large digitate spine near apex of declivity, its length at least 3 its basal diameter ( Fig. 5 A–B ).................................................................................................... brownei Atkinson & Flechtmann

- Declivital margin without large spines near apex, either without large spines or largest spines near midpoint of declivity ( Fig. 5 A–D )............................................................................................... 6

6 Interstria 1 on declivity with a row of small pointed tubercles; raised lateral margin of declivity with small pointed granules; transition from elytral disc to declivity pronounced, not gradual ( Fig. 5 A,B )....................... cavipennis Eichhoff

- Interstria 1 on declivity without any granules; several large, pointed tubercles near base and midpoint of declivity on lateral margin; base of declivity extends gradually anteriorad at base along insterstria 1 ( Fig. 5 , C,D)....... ambitiosus (Schaufuss)

Figures

FIGURE 4. Dorsal and posterolateral views of declivities of Neotropical species of Premnobius, part 1. A,B. P. neoadjunctus (Schedl); C,D. P. perezdelacrucei Petrov & Atkinson; E,F. P. flechtmanni (Wood); G,H. P. assiduus (Schedl). Photographs by T.H. Atkinson.

FIGURE 5. Dorsaland posterolateral views of declivities of Neotropicalspecies of Premnobius, part 2.A,B. P.browneiAtkinson & Flechtmann; C,D. P. ambitiosus (Schaufuss); E,F. P. cavipennis Eichhoff. Photographs by T.H. Atkinson.