Firebugs (Pyrrhocoris apterus) [1], especially nymphs but adults as well, can be found in large numbers on Common mallow (Malva sylvestris) where they feed on the developing seeds.
Literature
1 Nederlands SoortenregisterPyrrhocoris apterus (Firebug)
Malva sylvestris (Common mallow)Firebugs (Pyrrhocoris apterus) [1], especially nymphs but adults as well, can be found in large numbers on Common mallow (Malva sylvestris) where they feed on the developing seeds.
Literature
1 Nederlands Soortenregister