Synuchus congruus ( Morawitz, 1862 )

Kazulka, Mikalai, Anichtchenko, Alexander & Aleksandrowicz, Oleg, 2025, Discovery of Synuchus congruus (Morawitz, 1862) (Coleoptera, Carabidae, Sphodrini) in Europe, ZooKeys 1247, pp. 127-135 : 127-135

Synuchus congruus ( Morawitz, 1862)

Taphria congrua Morawitz, 1862

Synuchus latus Tschitschérine, 1893

Taxonomic remarks.

The genus Synuchus has been represented in Europe by a single widespread species Synuchus vivalis . It can be easily distinguished from other European Sphodrini Laporte, 1834 by the following features: dilated last labial palpomere, serrated tarsal claws, rounded base of the pronotum, prosternal process without a border, and characteristic shape of the aedeagus ( Lindroth 1956; Aßmann 2004). Despite the extreme similarity in habitus (Figs 1 , 2 ), the morphology of numerous specimens recorded over the past few years differed from that characteristic for S. vivalis . They have transverse reticulation on the elytra (rounded / isodiametric in S. vivalis ) (Figs 3 , 4 ), rather faint reticulation on the base and disc of pronotum (clearly visible in S. vivalis ) (Figs 5 , 6 ), weaker reticulation on forehead and vertex (clearly visible in S. vivalis ), and deeper lateral furrows on middle and hind tarsi (weaker in S. vivalis ). The differences also concern the shape of the aedeagus, the apex of which is short and rounded, and the median lobe in dorsal view is almost symmetrical (in S. vivalis the apex is elongated and curved upward, and the median lobe in dorsal view is asymmetrical and enlarged to the right) (Figs 7 , 8 ). Careful examination of these specimens showed that their morphology corresponds to the characteristics of S. congruus given by Lindroth (1956) and Lafer (1989), and they are clearly conspecific with specimens of S. congruus from Eastern Siberia and the Russian Far East.

Collection and habitat data.

Specimens of S. congruus were collected from multiple locations in western and central Belarus, northern and eastern Poland, and Latvia (Fig. 9 ). They were mainly found in forests, with several specimens in fallow fields and meadows. One was caught in bush thickets near a river. Almost all specimens were collected using pitfall traps or sifted from leaf litter, except for one, which was found in the fruiting body of Pleurotus sp. on a fallow oak tree in an old-growth oak forest.

Locality data.

Belarus – Minsk region: Dzerzhinsky distr., near Volmechka vlg. (UTM code: MV 96 ), 53°50'44"N, 26°55'15"E, meadow, pitfall traps: 1 ex., 9.X.2011, leg. V. Lukin ( SPCM) • Dzerzhinsky distr., near Volmechka vlg. ( MV 96 ), 53°50'47"N, 26°56'16"E, meadow, pitfall traps: 1 ex., 9.X.2011, leg. V. Lukin ( SPCM) • Minsk (NV 37), 53°56'35"N, 27°33'11"E, municipal woodland, hand collecting: 1 ex., 1.VIII.2020, leg. V. Kuznetzov (cKuz) – Brest region: Kamenets dist., near Lyatskie vlg. (FD 93), Białowieża Forest (Belovezhskaya Pushcha National Park) , 52°36'56"N, 23°52'30"E, birch forest, pitfall traps: 2 ex., 8.IX–11.X.2017, leg. O. Prischepchik ( SPCM) • Kamenets dist., near Lyatskie vlg. (FD 93), Białowieża Forest , 52°35'19"N, 23°51'42"E, hornbeam forest, pitfall traps: 1 ex., 26.X–7.XI.2024, leg. M. Kazulka ( SPCM) • Kamenets dist., near Lyatskie vlg. (FD 93), Białowieża Forest , 52°36'11"N, 23°51'39"E, oak forest, pitfall traps: 1 ex., 26.X–7.XI.2024, leg. M. Kazulka ( SPCM) • Kamenets dist., near Lyatskie vlg. (FD 93), Białowieża Forest , 52°35'14"N, 23°52'33"E, oak-hornbeam forest, pitfall traps: 1 ex., 26.X–7.XI.2024, leg. M. Kazulka ( SPCM) • Kamenets dist., near Kamenyuki vlg. (FD 83), Białowieża Forest , 52°36'18"N, 23°47'48"E, oak forest, hand collecting (on Pleurotus sp. ): 1 ex., 18.VIII.2021; pitfall traps: 4 ex., 26.X–7.XI.2024, leg. M. Kazulka ( SPCM) • Brest dist., Tomashovka vlg. (FC 71), Pribuzhskoe Polesie Biosphere Reserve , 51°33'18"N, 23°35'30"E, pine forest, pitfall traps: 1 ex., 16.III–17.IV.2022, leg. V. Kuznetzov (cKuz) • Brest dist., near Orkhovo vlg. (FC 81), Pribuzhskoe Polesie Biosphere Reserve , 51°31'29"N, 23°37'17"E, broadleaved forest, pitfall traps: 13 ex., 16–23.X.2021; 10 ex., 23–30.X.2021; 31 ex., 31.X–16.XI.2021; 11 ex., 16.XI.2021 – 12.II.2022, leg. V. Kuznetzov (cKuz) • Brest dist., near Orkhovo vlg. (FC 81), Pribuzhskoe Polesie Biosphere Reserve , 51°31'55"N, 23°36'39"E, broadleaved forest, hand collecting: 1 ex., 16.X.2021; pitfall traps: 1 ex., 27.III–11.IV.2021, leg. V. Kuznetzov (cKuz); 7 ex., 30.X–6.XI.2023, leg. M. Kazulka ( SPCM) – Grodno region: Volkovysk dist., near Zvezdnaya vlg. ( LU 39 ), Zamkavy Les Landscape Reserve , 53°12'49"N, 24°31'09"E, oak forest, pitfall traps: 1 ex., 24.VI–4.VIII.2022; 16 ex., 4.VIII–6.IX.2022; 11 ex., 6.IX–6.X.2022, leg. M. Kazulka ( SPCM) • Oshmyany dist., near Pratskovshchina vlg. (MA 33), 54°28'44"N, 25°58'37"E, oak-aspen forest, pitfall traps: 4 ex., 5.IX–5.X.2022, leg. M. Kazulka ( SPCM) .

Latvia – Bārbele parish, Bauska municipality (LC 45), 56°27'00"N, 24°32'04"E, bush thickets near a river, pitfall trap: 1 ex., 8–11. VIII. 2024 ( DUBC) .

Poland – Pomeranian Voivodeship: near Widzino vlg. (XA 23), 54°25'41"N, 16°58'23"E, fallow field, pitfall traps: 1 ex., 22.V–5.VI.2007; 1 ex., 22.VII–9.VIII.2007; 5 ex., 20.IX–8.X.2007; 4 ex., 8.X–3.XI.2007; 6 ex., 3–20.XI.2007, leg. M. Czyżykowska ( PUIB) • Słupsk city (XA 33), 54°26'38"N, 17°03'23"E, oak-beech municipal forest, pitfall trap: 1 ex., 15–30.XI.2009, leg. O. Aleksandrowicz ( PUIB) • Słupsk city (XA 23), 54°29'01"N, 16°59'30"E, fallow field, pitfall trap: 1 ex., 1–20.XI.2012, leg I. Mrozowicz ( PUIB) • Near Niepoględzie vlg. (XA 51), 54°17'27"N, 17°22'38"E, wooded strip (hornbeam forest), pitfall traps: 9 ex., 15.X–11.XI.2010, leg. M. Janusiak ( PUIB) – Podlaskie Voivodeship: near Białowieża vlg. (FD 94), Białowieża Forest (Białowieża National Park) , comp. 399 C, 52°43'04"N, 23°50'52"E, oak – hornbeam forest, pitfall traps: 2 ex., 31.VII.2012, leg. J. Gutowski ( FRI) .

Figures

Figure 9. Occurrence map of Synuchus congruus in Belarus, Latvia, and Poland.

Figures 1, 2. Habitus of Synuchus. 1. S. vivalis; 2. S. congruus. Scale bar: 5 mm.

Figures 3–6. Microreticulation in Synuchus (males). 3, 4. on elytra; 5, 6. on base of pronotum; 3, 5. S. vivalis; 4, 6. S. congruus. Scale bars: 0.15 mm (3, 4); 0.3 mm (5, 6).

Figures 7, 8. Aedeagus of Synuchus in lateral and dorsal view. 7. S. vivalis; 8. S. congruus. Scale bar: 1 mm.