Dorcadion fulvum subsp. opillicum Zamoroka 2019

Field: Agricultural and Biological Sciences (Life Sciences)

Dorcadion fulvum opillicum Zamoroka, 2019 Material. Type. Holotype ♂: Ukraine: Ivano-Frankivsk: Kuropatnyky, 49.286027 N, 24.669622 E, 19.06.2015 (Zamoroka) (PUIF). Paratype: 1♀, same labels as in holotype (PUIF). Non-type. Poland: Lublin Upland, UTM GB03, Gródek, Hrubieszów County, 50.795858 N, 23.957577 E (fig. 1A), 3♂, 2♀ 01.05.2009 (obs. T. Olbrycht). One specimen is deposited in PUIF. Our record of Dorcadion fulvum is one of the few recent findings of this species in Poland. This refutes the assumption of the possible extinction of this species here. On the other hand, this proves an idea that D. fulvum is widespread within Roztocze and Lublin Upland. However, its range is not continuous, but represents a number of isolated islands. Our observations in Nadbużański Obszar Chronionego Krajobrazu and the Natura 2000 site “Zachodniowołyńska Dolina Bugu ” (PLH 060035) showed that the most typical habitats for D. fulvum are xerothermic Thalictro-Salvietum pratensis complex grasslands on the southern steep slopes of the hills along the Bug River (fig. 1A). Very rarely, D. fulvum occurs on arable lands or other agricultural or seminatural areas. It should be emphasised that the observed habitat differs from those in D. f. opillicum type locality. This includes other types of vegetation (Brachypodietalia pinnati and Festucetalia valesiacae) and soil composition (contained amount of crushed gypsum debris) within type locality (Zamoroka, 2019). Comparison of Dorcadion fulvum samples from the vicinity of Gródek, Hrubieszów County with both subspecies of D. f. erythropterum and D. f. opillicum shows general morphological resemblance to the latter. First of all, this includes more or less dark integument coloration, especially of elytra. In addition to the common dark forms (fig. 1B) at the studied site there are specimens of partially dark colour (Fig. 2, B) or completely light (fig. 1C), which resemble D. f. erythropterum. In a type series of D. f. opillicum light-coloured specimens constitute about 27% (Zamoroka, 2019). Secondly, elytra of studied specimens are roughly sculpted with a well-developed humeral rib (especially in females) similar to D. f. opillicum. Elytra of males and females are more or less dimmed by dense coarse punctation and wrinkling. Contrary to them, the elytra sculpture of D. f. erythropterum is significantly smoothed with a clear sheen, without a distinct rough punctation. Finally, the elongated labrum and convex occiput are inhered in Dorcadion fulvum from the vicinity of Gródek. These features are typical for D. f. opillicum. The aedeagi of both D. fulvum from Gródek and D. f. opillicum are almost identical, sharing the shape and proportions of proximal and distal parts (Fig. 3). In particular, their ventral and dorsal lobes are big and long, contrary to those in D. f. erythropterum. The ratio of proximal and distal parts of aedeagus constitutes near 1:1 (fig. 3D–E), which is different from that ratio in D. f. erythropterum (Fig. 3F). These clearly indicate that D. fulvum from Gródek belongs to the recently described subspecies D. f. opillicum. It should be noted that the aedeagus apex of D. fulvum from Gródek (fig. 3B) is less sclerotized and less deeply truncated than in the holotype of D. f. opillicum (fig. 3A). Dorcadion fulvum from Gródek and D. f. opillicum also share morphological features of the tegmens (fig. 4). Their parameres are elongate, punctated on internal side and covered by short pubescence from their base to the apex. The tegmal ring of D. fulvum from Gródek is relatively short and near the same length that parameres, which is similar to D. f. opillicum, whereas in D. f. erythropterum (fig. 4C, F) the parameres are short and the tegmal ring is strongly elongated. Our data convincingly indicate that D. fulvum from South-Eastern Poland belong to the recently described subspecies D. f. opillicum. This is evidenced by both the similarity of external morphology and the structure of the male genitalia. Our findings also have biogeographical implications as they extend the known range of D. f. opillicum west to the Wisła and north to Polissya (fig. 5). However, the eastern boundaries of its range and the location of the introgression zone between D. f. opillicum and D. f. erythropterum still remain unresolved.