Key to species and subspecies of Silphidae recorded from Turkey

The characters used in the key were taken from Šustek (1981), Peck (1990), Piloña & Valcárcel (2002), Sikes (2003) and Qubaiová et al. (2015). In Nicrophorus, characters based on setation of pronotum, metaventrite and abdominal segments are sometimes hardly visible on abraded specimens.

1 Antennomere 2 small and hardly visible, which makes the antenna seemingly 10 segmented (as on Fig. 22). Last four antennomeres abruptly widened into a distinctly swollen club (as on Figs. 1–7 and 22–24). Clypeal membrane membranous, sometimes contrastingly coloured (as on Figs. 22–23). Body rounded to oval on transverse section, elytra truncate. Fifth abdominal tergum with a pair of stridularory files. Nicrophorinae, Nicrophorus ........................................... 15

- Antennomere 2 fully developed, antenna with 11 distinct antennomeres (as on Fig. 21). Antennal club elongate, antennomeres only gradually widening into club (as on Fig. 21). Clypeal membrane sclerotized (as on Fig. 21). Body flattened, elytra usually covering all or most of abdomen. Fifth abdominal tergum without stridulatory files. Silphinae ....................... 2

2 Pronotum pale yellow with large median black spot, elytra pale yellow with 4 black spots (Fig. 11)................................................................................................... Dendroxena quadrimaculata

- Elytra uniformly brown to black.......................................................................... 3

3 Eyes very large, laterally prominent, head abruptly narrowed behind eyes (Fig. 12). Antennae black with last three antennomeres pale orange (Fig. 12). Pronotum orbicular, widest toward middle (Fig. 12). Moderate to large males with metafemora swollen and toothed toward apex........................................................... Necrodes littoralis

- Eyes smaller, laterally not prominent, head with developed tempora behind eyes (as on Fig. 21). Antennae fully black (as on Fig. 21), some antennomeres brown only in teneral specimens (as on Fig. 18). Pronotum usually widest toward base, not orbicular (as on Fig. 18). Metafemora of males never swollen or toothed............................................. 4

4 Intermediate coxae separated by a space equal or larger than the width of the femora of the same pair.................. 5

- Intermediate coxae separated by a space smaller than the width of the femora of the same pair........................ 8

5 Pronotum orange (Fig. 21). Head with a short row of prominent longer and more erect setae laterally just behind eyes (Fig. 21). Third elytral ridge ending on the posterior callus, surface of elytra with velvet pubescence (Fig. 21). Oiceoptoma thoracicum

- Pronotum dark brown to black (Fig. 18–20). Head without a row of prominent longer and more erect setae laterally behind eyes (Figs. 18–20). Third elytral ridge exceeding the posterior callus more posteriorly, surface of elytron matt (Figs. 18–20). Thanatophilus ....................................................................................... 6

6 Surface of elytra between elytral ridges with transverse irregular ripples (Fig. 18)................. Thanatophilus rugosus

- Surface of elytra between elytral ridges simple, without irregular ripples (Figs. 19–20).............................. 7

7 Lateral portion of pronotum and elytra red-brown in fully mature specimens (Fig. 20). Third elytral ridge shorter, not exceeding the callus (Fig. 20). Second elytral ridge straight (Fig. 20). Elytral shoulders rounded (Fig. 20). Thanatophilus terminatus

- Lateral portion of pronotum and elytra black (Fig. 19) (brown only in teneral specimens). Third elytral ridge exceeds the callus posteriorly (Fig. 19). Posterior portion of second elytral ridge curved outwards (Fig. 19). Elytral shoulders with small tooth (Fig. 19)........................................................................... Thanatophilus sinuatus

8 Labrum deeply grooved, dorsally elevated (Fig. 10). Head distinctly transverse, pronotum about twice as broad as head across eyes (Fig. 10). Tempora not narrowed behind the eyes. Elytra with irregular ripples and wrinkles between ridges (Fig. 10). Phytophagous species...................................................................... Aclypea undata

- Labrum weakly grooved, flat (as on Figs 8, 13–15). Head less transverse, pronotum about 2.5 to 3.5 as broad as head across eyes (Figs. 8–9, 13–17). Elytra smooth.................................................................... 9

9 Head not prolongated, about as long as wide across eyes, tempora behind eyes short (Fig. 14–17). Unmodified polyphagous species. Silpha ....................................................................................... 12

- Head distinctly prolongated, longer than wide across eyes, tempora behind eyes elongated. Head adapted to predation of snails in shells (Figs. 8–9, 13)............................................................................... 10

10 Elytra with distinctly developed, elevated ridges (Fig. 13). First antennomere as long as combined length of antennomeres 2–4.................................................................................. Phosphuga atrata atrata

- Elytra without elevated ridges (Figs 8–9). First antennomere slightly longer than combined length of antennomeres 2–3. Ablattaria . .............................................................................................. 11

11 Pronotum with evenly distributed, homogenous, distinct punctures on whole dorsal surface (Fig. 9). Elytra with medium-sized, distinct punctures of similar size (Fig. 9)................................................... Ablattaria laevigata

- Pronotum with only very superficial, very fine punctures medially on disc (which looks impunctate under lower magnification), much larger punctures on whole dorsal surface (Fig. 8). Elytra with fine punctures, intermixed with larger ones, dispersed mostly toward the inner elytral margin (Fig. 8).......................................... Ablattaria arenaria

12 Elytral punctures without anterior shining granule. Rows of punctures along elytral ribs distinctly smaller than on interstriae (Fig. 14–15)........................................................................................ 13

- Elytral punctures with anterior shining granule present. Rows of punctures along elytral ribs equal in size with ones on interstriae, sometimes with intermixed large punctures (Figs 16, 17)................................................ 14

13 Elytra dull with small, oval punctures, surface between elytral punctures smooth (Fig. 14).......... Silpha obscura obscura

- Elytra shiny with larger, mostly subquadrate punctures, surface between elytral punctures with granulation (Fig. 15)......................................................................................... Silpha obscura orientalis

14 Pronotal punctuation dense and deep, the distance between adjacent punctures smaller than the diameter of a puncture (Fig. 17). Elytral punctuation arranged in regular pattern, diameter of punctures uniform (Fig. 17). Surface between adjacent punc- tures smooth and flat. Elytral ridges distinctly marked (Fig. 17)....................................... Silpha tristis - Pronotal punctuation very fine and superficial, the distance between adjacent punctures larger than the diameter of a puncture (Fig. 16). Elytral punctuation arranged in irregular pattern; punctures fine and superficial, with irregularly intermixed larger punctures close to ridges (Fig. 16). Surface between adjacent punctures irregular and convex. Elytral ridges more superficial, less elevated (Fig. 16)....................................................................... Silpha olivieri

15 Elytra uniformly black or black with reddish-orange isolated spots (Figs. 2–3)................................... 16

- Elytra with two orange or yellowish bands interrupting black coloration, sometimes fused, then most of elytra with orange pattern (Figs. 1, 4–7, 22–24).............................................................................. 17

16 Antennal club with basal antennomere black, apical three antennomeres orange (Fig. 3). Elytral epipleura black. Elytral disc black, only rarely with orange spots (Fig. 3). Metatibia straight on outer margin, simply expanding posteriad (Fig. 3)............................................................................................ Nicrophorus humator

- Antennal club black (Fig. 2). Elytral epipleura orange. Elytral disc black, in Turkey quite frequently with isolated, orange-reddish spots (Fig. 2). Metatibia swollen at middle of outer margin (Fig. 2)...................... Nicrophorus germanicus

17 At least anterior margin of pronotum with dense, long golden setation (Figs. 1, 6–7, 23)............................. 18

- Pronotum glabrous or with only a few short hairs near the anterior angles (Figs. 4–5, 22, 24)......................... 21

18 Metatibiae curved (Figs. 6, 23). Pronotum with dense, long golden setation only along anterior margin (Fig. 6, 23)....... 19

- Metatibiae straight (Figs. 1, 7). Pronotum with long golden hair on both anterior and posterior margin................. 20

19 Antennal club black (Fig. 6). Metatibiae with accessory spine short, not surpassing apex.......... Nicrophorus nigricornis

- Antennal club with basal antennomere black, apical three antennomeres orange (Fig. 23). Metatibiae with accessory spine long, surpassing apex................................................................... Nicrophorus vespillo

20 Antennal club entirely orange (Fig. 1).................................................. Nicrophorus antennatus

- Antennal club with basal antennomere black, apical three antennomeres orange (Fig. 7)............ Nicrophorus vestigator

21 Antennal club entirely black (Fig. 24). Clypeal membrane black (Fig. 24)..................... Nicrophorus vespilloides

- Antennal club with basal antennomere black, apical three antennomeres orange (Figs. 4–5, 22). Clypeal membrane orange (as on Fig. 22).......................................................................................... 22

22 Metaventrite with extremely short, yellow setae behind metacoxae. All abdominal segments with black setae on posterior margins (Fig. 22)......................................................................... Nicrophorus sepultor

- Metaventrite with long, yellow setae behind metacoxae. At least the apical abdominal segment posteriorly with yellow setae (Figs. 4–5)......................................................................................... 23

23 Metaepimera with posterior lobe glabrous or with a very few short setae. Abdomen with posterior margins of segments with yellow setae only on last visible segment, other segments with black setae (Fig. 5)............... Nicrophorus investigator

- Metaepimera with posterior lobe with many long setae. Abdomen with posterior margins of segments with yellow setae at least on several apical segments, usually on all visible segments (Fig. 4)........................... Nicrophorus interruptus