Faunistic survey of myrmecophilous and other ant-associated beetles and spiders in the Belgian province of Limburg (Araneae, Coleoptera, Hymenoptera: Formicidae) Author Berx, Peter Author Bosmans, Bart Author Dekoninck, Wouter Author Janssen, Marc Author Stassen, Eugène Author Crevecoeur, Luc text Belgian Journal of Entomology 2023 2023-10-06 141 1 61 journal article 10.5281/zenodo.12639020 2295-0214 12639020 57BE72E5-DFC7-4A81-8912-0F6623FC794D Histeridae Gyllenhal, 1808 Most of the specimens of Abraeus granulum ( 1.2-1.5mm ) ( Fig. 14A ), 51 of the 61 collected (Annex), have been found in sieve samples from decaying wood in Kolmontbos, Tongeren. The species is common in deciduous woodland with no specific preference for a typical tree but can be found on any decayed tree, colonized by saproxylic ants ( Lasius spp. ) or not. Abreus parvulus ( 1.2-1.5 mm ) is rather rare, at least in Limburg, with only five specimens from two locations (Kolmontbos, Tongeren and Jongenbos, Kortessem). In obvious dissimilarity to the latter species, Abraeus perpussilus (1.0- 1.5 mm ) ( Fig. 14 B ) is widely distributed with 1,551 captured specimens in 62 1 x 1 km grids (Annex). Aeletes atomarius (1.0 mm) ( Fig. 14 C ) does not show a general distribution pattern in Limburg, which seems to be contradicted by the high number of individuals in Limburg (Annex). The explanation is that they can be found in a collectively large number of several dozen. On one occasion by sifting the wood of a northern red oak ( Quercus rubra L. (1753)) and the tinder fungus ( Fomes fomentarius (L.) Fr., 1849) present, that grew on the edge of a pond, 286 adult beetles were sampled ( 8 May 2020 , Hoefaert, Lanaken, FS8140). Jussi PÄivinen ( PÄIVINEN et al ., 2002 ) mentions the symbiotic correlation of A. atomarius with the ant Lasius niger referring to data prior to 1991, the year in which Bernhard Seifert ( SEIFERT, 1991 ) emphasized the ecological difference between L. niger and L. platythorax . The latter prefers nest constructions in woodland avoiding urban habitats and it is most probable the species that is found with A. atomarius . With 75 1 x 1 km grids, Paromalus flavicornis ( 1.5-2.2 mm ) ( Fig. 14 D ) is the most common histeridid species observed in Limburg (Annex) which is in line with the general pattern for Europe where this species is also widely distributed. Adult specimens can be found throughout the year and feel at home on both conifers and deciduous trees. While many species of saproxylic beetles are usually found with a few trapping techniques such as sifting, this species is caught with just about every set-up used in this study. Plegaderus dissectus (1.0- 1.5 mm ) ( Fig. 14 E ) is another common histeridid of which many individuals were observed (Annex). Of this beetle, seven specimens have been found in the extraction sample from Hoefaert, Lanaken together with A. atomarius (cf. supra). Like several species of this family, P. dissectus can be found under tree bark where it preys on bark beetle larvae.