Actidium variolatum Flach, 1887

Komosiński, Karol & Marczak, Dawid, 2018, Four Species of Ptiliidae (Coleoptera) New to Poland, The Coleopterists Bulletin 72 (1), pp. 151-156 : 152

Actidium variolatum Flach, 1887

In Europe, the genus Actidium is represented by seven species, of which only two are reported from Poland: Actidium aterrimum (Motschulsky, 1845) and A. boudieri (Allibert, 1844) ( Sörensson 2015) . Actidium coarctatum (Haliday, 1855) , a halophilous species, was reportedly collected during the 19 th century in the territory of former East Prussia. This site is currently located in Kaliningrad ( Russian Federation), but specimens from that region have been found in collections ( Horion 1949; Bercio and Folwaczny 1979). Therefore, A. coarctatum was not included in the list for the Polish fauna ( Burakowski et al. 1978).

A new country record for Poland, A. variolatum stands out among other species of this genus due to the clearly marked and dense punctation on the prothorax, especially at its base, and the black coloration of the antennae. Only A. coarctatum has equally clear and dense punctation of the prothorax, however, its antennae are bright yellow.

Currently, A. variolatum is only reported from five European countries: Croatia (Dalmatia), France (Upper Savoy), Switzerland (Canton of Vaud), Germany (Brandenburg), and Austria ( Besuchet 1971; Sörensson 2015). The species seems to be widely distributed in central Europe ( Besuchet 1976). In the German Red List, it is listed as an extinct species ( Binot et al. 1998). This beetle inhabits damp habitats and is found in swampy areas, among mosses and sedges. In Brandenburg, Germany, it was collected from under lichens ( Koch 1989).

Material Examined. Mazovian Lowland (central Poland): Kampinos National Park , Strict Protected Area Zaborów, forest spatial unit 269 (N 52°18 ʹ 32 ʹʹ, E 20°43 ʹ 21 ʹʹ), 1–31 VII 2016 – 1 ex., collected by barrier trap hanging on an alder, habitat Ribeso nigri-Alnetum with alder trees over 130 years old, leg. D. Marczak, coll. K. Komosiński.