Ptinella populicola Vorst

Vorst, Oscar, 2012, A new invasive Ptinella Motschulsky from Europe and North America (Coleoptera: Ptiliidae), Zootaxa 3270, pp. 63-66 : 64-65

Ptinella populicola Vorst , new species

( Figs. 1–6 )

Diagnosis. A relatively large and broad Ptinella ( Fig. 1 ), dorsum dull, spermatheca as in Fig. 4 . Dimorphic. Description. Forma alata. Body rather broad, yellowish brown to brown, antennae and legs yellowish. Length (front of head to elytral apex): 0.62–0.70 mm (median 0.68 mm, N = 16).

Head strongly reticulate, dull. Eyes well developed. Head width: 0.24–0.27 mm (median 0.25 mm, N = 16). Antennae ( Fig. 2 ) rather long: 0.35–0.38 mm (median 0.37 mm, N = 7).

Pronotum 1.55–1.75 × as broad as long, widest before middle. Pronotal length: 0.18–0.20 mm (median 0.19 mm, N = 16), pronotal width: 0.28–0.32 mm (median 0.30 mm, N = 16). Frontal margin slightly emarginate, longer than hind margin. Fore angles bluntly protruding. Sides finely beaded, strongly curved, and sinuate before hind angles, which are clearly rectangular. Surface strongly reticulate, dull, as on head.

Elytra 1.8–2.0 × as long as pronotum. Elytral length: 0.35–0.38 mm (median 0.35 mm, N = 13). Widest at about middle. Basal margin somewhat longer than hind margin of pronotum. Shoulders clearly denticulate. Surface reticulate with meshes larger and less pronounced than on head and pronotum, clearly granulate, somewhat more shining than head and pronotum. Epipleural carina distinct basally, hardly visible from above.

Female: spermatheca characteristic ( Fig. 4 ). Pygidium with apical tooth.

Male of forma alata is unknown.

Forma aptera. Similar to forma alata, but differing in the following aspects. Body yellowish brown, smaller: length (front of head to elytral apex): 0.58–0.62 mm (N = 3).

Eyes weakly developed with only about 10 ommatidia. Head width: 0.21–0.23 mm (N = 3). Antennal length: 0.33–0.35 mm (N = 3).

Pronotal length: 0.16–0.17 mm (N = 3), pronotal width: 0.27–0.28 mm (N = 3).

Elytral length: 0.30–0.33 mm (N = 3). Widest at about middle. Basal margin somewhat longer than hind margin of pronotum. Pygidium with apical tooth ( Fig. 3 ).

Male: aedeagus as in Figs. 5–6 .

Female of the forma aptera is unknown.

Type material. Holotype: Ψ forma alata, "Liempde, Vleeschbroek / 154.9-396.8 V4456M / 28.vii.2010 / leg. O.Vorst / Schors Populus" ( RMNH), collected near Liempde ( The Netherlands, Province of Noord-Brabant). Cardmounted, dissected, spermatheca and abdominal segments mounted in PVP ( Lompe 1989) on the same card. Paratypes: THE NETHERLANDS: Province of Noord-Brabant: ɗ (forma aptera) 14 ΨΨ (forma alata), Biesbosch, De Gijster, 25.viii.2010, under fermenting bark of standing dead poplar (Populus sp.), O. Vorst (cOV, MCZ, RMNH, USNM); 2 ɗɗ (forma aptera) 3 ΨΨ (forma alata), Liempde, Vleeschbroek, 28.vii.2010, under loose bark of wind-felled poplar (Populus sp.), O. Vorst (cOV, RMNH). Other material: USA: Maryland: Ψ 3 spec. (forma alata), Plummers I[sland], 12.xi.1911, Schwarz & Barber ( USNM); 2 spec. (forma alata), Plummers I[sland], 9.x.1912, Schwarz & Barber ( USNM).

Distribution. So far only known from the Netherlands and Maryland, USA.

Bionomics. All Dutch specimens were collected from under bark of dead poplar trees (Populus sp.).

Etymology. The specific epithet is a substantive in apposition derived from Populus [poplar] and the Latin suffix - cola [inhabitant], referring to the microhabitat at both Dutch collecting sites.

Figures

FIGURE 1 – 3. Ptinella populicola, habitus female forma alata (1), antenna (2) and male pygidium (3). Scale bar 0.2 mm (1) or 0.1 mm (2, 3).

FIGURE 4 – 6. Ptinella populicola, spermatheca (4) and aedeagus in lateral (5) and dorsal (6) view. Scale bar 0.05 mm.