Omaliinae MacLeay, 1825

Berx, Peter, Bosmans, Bart, Dekoninck, Wouter, Janssen, Marc, Stassen, Eugène & Crevecoeur, Luc, 2023, Faunistic survey of myrmecophilous and other ant-associated beetles and spiders in the Belgian province of Limburg (Araneae, Coleoptera, Hymenoptera: Formicidae), Belgian Journal of Entomology 141, pp. 1-61 : 36

Omaliinae MacLeay, 1825

Omalium rivulare (3.0-4.0 mm) ( Fig. 29 C ) is described as the most common species of the genus and prefers warm summer evenings to disperse by flying. Consequently, this rove beetle has been captured in large numbers with flight-interception traps. But concentrations from ten to 39 individuals were also observed when sieving decaying mushrooms. The genus Phloeonomus Heer, 1839 is represented by three species in the province of Limburg: P. minimus (Erichson, 1839) (1.3-1.6mm), P. punctipennis Thomson, 1867 (1.7-2.0 mm) ( Fig. 29 D ) and P. pusillus (Gravenhorst, 1806) (1.7-2.0 mm). We were only able to demonstrate the relationship with L. brunneus for P. punctipennis . Phloeonomus minimus is not as common as P. punctipennis but since both these species share the same biotope preference, namely deciduous forests, it is plausible that P. minimus could also be noticed in the vicinity of a nest of L. brunneus . Phloeonomus pussilus , on the other hand, is mainly bound to coniferous forests, which makes an association with L. brunneus less likely. The ant L. brunneus is common in deciduous forests but avoids dense coniferous forests (SIEFERT, 1992). Xylodromus affinis (3.2-3.7mm) ( Fig. 29F ) has been reported as a beetle living in the nests of the mole and the hamster ( SAINTE-CLAIRE DEVILLE, 1912). This may explain the fact that this rove beetle is only encountered sporadically and is reported as rather rare. In Rullen (FS9922), a hamlet in the municipality of Voeren ( Figure 2 ) one single specimen was captured with a subterranean pitfall trap (i.e., an 80 cm long PVCtube with several perforations and a recipient at the bottom with a storage liquid, sunk directly into the soil) set up under a hornbeam ( Carpinus betulus L. (1753)). The single observation near a nest of L. fuliginosus (Tongeren – Table 26) should therefore be assessed from this perspective.

Figures

Fig.29. A, Anthobium unicolor (Marsham, 1802) (3.5 mm; range 3.0-3.5mm). B, Coryphium angusticolle Stephens, 1834 (3.0mm; range 2.5-3.0mm). C, Omalium rivulare (Paykull, 1789) (3.8mm; range 3.0-4.0mm). D, Phloeonomus punctipennis Thomson, 1867 (1.9mm; range 1.7-2.0 mm). E, Phyllodrepa ioptera (Stephens, 1834)) (2.6mm; range 2.5-3.0mm). F, Xylodromus affinis (Gerhardt, 1877) (range 3.2-3.7mm). © U. Schmidt.

Fig.2. Community Voeren with indication (yellow symbols) of the locations mentioned in the tables. Toponyms: FS9127 Moelingen; FS9526 Vitchen; FS9626 Altenbroek; FS9725 Schoppem; FS9727 Altenbroek orchard; FS9825 Berg; GS0024 Veurs; GS0123 Kijs; GS0227 Gulp; GS0424 Middelhof.