Lasius flavus (Fabricius, 1782)

BELGIUM: • 3 ♂♂; N51.197° E4.463°; viii/2020; J. Jacobs leg.; coll. RBINS; pitfall trap; W. Dekoninck det. • 1 ♂; N51.237° E4.457°; viii/2020; J. Jacobs leg.; coll. RBINS; pitfall trap; W. Dekoninck det. • 1 ♂; N51.197° E4.462°; ix/2020; J. Jacobs leg.; coll. RBINS; pitfall trap; W. Dekoninck det. • 2 ♂♂; N51.184° E4.420°; ix/2020; J. Jacobs leg.; coll. RBINS; pitfall trap; W. Dekoninck det. • 1 alate gyne, 3 dealate gynes, 4 ♂♂; N51.199° E4.459°; viii/2021; J. Jacobs leg.; coll. RBINS; pitfall trap and pan trap (red); W. Dekoninck det. • 1 ♂ + 1 dealate gyne; N51.197° E4.463°; viii/2021; J. Jacobs leg.; coll. RBINS; pitfall trap; W. Dekoninck det. • 1 ♂; N51.197° E4.462°; viii/2021; J. Jacobs leg.; coll. RBINS; pan trap (blue); W. Dekoninck det. • 1 ♂; N51.184° E4.419°; viii/2021; J. Jacobs leg.; coll. RBINS; pitfall trap; W. Dekoninck det. • 1 ♂; N51.135° E4.241°; viii/2021; J. Jacobs leg.; coll. RBINS; pitfall trap; W. Dekoninck det. [9 occ. (2 years), 7 roofs]

Remarks:

We only found males and gynes of Lasius flavus and not a single worker. Also for this species we have no evidence of nests on the green roofs we sampled. In normal situations this species makes small (or sometimes big) mounds in grassland and tends aphids on the roots of these grasses (DEKONINCK et al., 2012; SEIFERT, 2018). Parts of the nest can be very deep in the ground especially during dry summers when grasses dry out. This is probably not an option for this species on green roofs.