Taphrorychus, Eichhoff

Key to Taphrorychus View in CoL species of Europe (not including European Russia; modified from Pfeffer, 1995)

Taphrorychus can be identified by a pronotum slightly longer than wide in dorsal view, with subparallel sides and a marked summit visible in lateral view. The apical half of the pronotum is asperate, while the basal half is punctate, smooth, slightly rugose and shagreened. The vestiture on the pronotum is similar to that covering the entire surface of elytral disc and declivity.

The following key, modified from Balachowsky (1949) and Pfeffer (1995), is intended to facilitate the identification of Taphrorychus occurring in Europe.

1 Pronotum subquadrate, with a distinctly marked median summit when viewed laterally; length 1.6–2.6 mm ............. 2

- Pronotum oblong, with no distinct summit when viewed laterally; length 1.2–2.0 mm.............. T. ramicola (Reitter)

2 Elytral declivity evenly arched in both sexes when viewed laterally; elytral declivity impunctate; elytral disc shagreened, without distinct rows of interstrial punctures; punctures faintly visible only along the sides of the elytra; interstrial setae seriate and robust; females without a dense tuft of setae on the frons; length <1.8 mm .................................... 3

- Elytral declivity flat and gradually descending in males, gradually rounded in females when viewed laterally; elytral declivity with rows of interstrial punctures; elytral disc shining, with distinct and dense striae and interstriae; punctures clearly visible along the sides of the elytra; interstriae with sparse setae and bristles; females with a tuft of a setae on the frons; length> 1.8 mm ................................................................................................ 4

3 Elytral declivity matt, without rows of strial punctures; elytra surface finely shagreened, setose on the sides and with long, erect, rows of light color setae in between; elytral disc rugose and without tubercles; elytral declivity with minute and uniform granules on interstriae 1, 3 and 5; pronotum base matt, without evident punctuation; length 1.6–1.8 mm .................................................................................................. T. hirtellus ♀ Eichhoff View in CoL

- Elytral declivity shiny, with rows of strial punctures; elytra surface extremely and finely punctured, very finely setose; elytral disc is smooth and the first interstriae are covered with single tubercles; elytral declivity without granules; pronotum base shiny, with fine and dense punctuation; length 1.8 mm ................................................ T. minor Eggers View in CoL

4 Frons bearing only sparse and short setae; elytral declivity appearing flat in lateral view, gradually descending, and clearly distinct from the elytral disc; males....................................................................... 5

- Frons bearing a rounded tuft of dense setae; elytral declivity appearing moderately to steeply arched in lateral view, not flattened; females............................................................................................. 8

5 Elytral declivity clearly punctured, with sharper edges and with single or multiple rows of punctures; declivital interstria 1 with 5–9 granules; elytra ≤ 1.70× or ≥ 1.80× longer than wide..................................................... 6

- Elytral declivity very finely punctured, nearly smooth, semi-matt, with rounded edges and with three rows of fine granules; declivital interstria 1 with 5 or 6 distinct granules; elytra 1.70–1.75× longer than wide; length 1.8–2.4 mm ............................................................................................... T. villifrons ♂ (Dufour) View in CoL

6 Declivital interstriae 1 with 5 or 6 very fine granules; declivity with clear edges, surface shiny with 1–2 shallow striae; elytra 1.6–1.7× longer than wide with heavily punctured striae and interstriae; length 1.6–2.5 mm ......... T. bicolor ♂ (Herbst) View in CoL

- Declivital interstriae 1 with 8 or 9 distinct granules; declivity with rounded edges, surface matt with clearly punctured striae; elytra 1.65–1.90× longer than wide with heavily punctured striae but very finely punctured interstriae; length 1.8–2.6 mm .. 7

7 Elytra 1.8–1.9× longer than wide; elytral declivity steep and shiny; length 1.8–2.6 mm ................. T. alni ♂ Pfeffer View in CoL

- Elytra 1.65–1.70× longer than wide; elytral declivity flatly curved and matt; length 2.0– 2.2 mm ...... T. siculus ♂ Eggers View in CoL

8 Elytral declivity irregular, with distinct rows of punctures; rows of granules are either absent or, if present, not necessarily aligned with declivital interstriae 1, 3 and 5; elytra 1.65–1.90× longer than wide................................... 9

- Elytral declivity smooth and uniform, with indistinct rows of punctures; rows of fine granules on declivital interstriae 1, 3, and 5; elytra 1.7–1.8× longer than wide; length 1.8–2.4 mm ................................... T. villifrons ♀ (Dufour) View in CoL

9 Elytral declivital interstriae bearing 8 or 9 granules in total; elytral striae strongly and densely punctured, while interstriae finely punctured; elytra 1.65–1.90× longer than wide............................................................. 10

- Elytral declivital interstriae without granules; elytral striae and interstriae strongly and densely punctured; elytra 1.80–1.85× longer than wide; length 1.6–2.5 mm .................................................... T. bicolor ♀ (Herbst) View in CoL

10 Elytra 1.85–1.90× longer than wide; elytral declivity shiny; length 1.8–2.6 mm ....................... T. alni ♀ Pfeffer View in CoL

- Elytra 1.65–1.75× longer than wide; elytral declivity matt; length 2.0– 2.2 mm .................... T. siculus ♀ Eggers View in CoL

Checklist of Taphrorychus View in CoL of Europe (not including European Russia)

Countries abbreviations follow ISO 3166-1 alpha-2 standard list.

Taphrorychus alni Pfeffer View in CoL

Distribution: E: FR (Southern France, Corsica) ( Alonso-Zarazaga et al. 2023).

Host plants: Alnus glutinosa .

Taphrorychus bicolor (Herbst)

Distribution: E: AT, BE, BA, BG, CH, CZ, DE, DK, ES, FR, GB, HR, HU, IT, LI, LT, ME, MK, NL, NO, PL, PT, RO, RS, RU, SE, SK, UA, “Caucasus”, A: IR, KP, KR, TR ( Alonso-Zarazaga et al. 2023).

Host plants: Carpinus betulus , C. orientalis , Fagus orientalis , F. sylvatica , Quercus petraea , Q. robur .

Taphrorychus hirtellus (Eichhoff)

Distribution: E: BA, BG, CZ, HR, HU, IT, ME, MK, RO, SK, N: DZ, A: TR ( Alonso-Zarazaga et al. 2023, this contribution).

Host plants: Corylus avellana , Fagus orientalis , F. sylvatica , Quercus cerris , Q. frainetto , Q. petraea .

Taphrorychus minor Eggers

Distribution: E: IT, N: DZ ( Alonso-Zarazaga et al. 2023).

Host plants: Quercus ilex .

Taphrorychus ramicola (Reitter)

Distribution: E: BG, ST, “Caucasus”, A: IR, SY, TR ( Alonso-Zarazaga et al. 2023).

Host plants: Carpinus orientalis , Corylus avellana , Fagus orientalis , Quercus cerris .

Taphrorychus siculus Eggers

Distribution: E: BA, IT (Sicily), SZ ( Alonso-Zarazaga et al. 2023)

Host plants: Alnus sp.

Taphrorychus villifrons (Dufour)

Distribution: E:AT, BE, BG, CH, CZ, DE, ES, FR, GB, HR, HU, IT, MK, PT, RU, RS, SK, UA, “Caucasus”, N: DZ, EG, LY, MA, TN, A: AM, IR, TR ( Alonso-Zarazaga et al. 2023).

Host plants: Carpinus betulus , C. orientalis , Castanea sativa , Fagus orientalis , F. sylvatica , Quercus canariensis , Q. castaneifolia , Q. castaneifolia var. incana , Q. cerris , Q. frainetto , Q. ilex , Q. lusitanica , Q. robur , Q. suber .