Intranest relatedness and nestmate recognition in the meadow ant Formica pratensis (R.)

The impact of intranest relatedness on nestmate recognition was tested in a population of polydomous and monodomous nests of the mound-building ant Fo rmica pratensis. Nestmate recognition was evaluated by testing aggression l evels between 37 pairs of nests (n = 206 tests). Workers from donor colonie s were placed on the mounds of recipient nests to score aggressive interact ions among workers. A total of 555 workers from 27 nests were genotyped usi ng four DNA microsatellites. The genetic and spatial distances of nests wer e positively correlated, indicating budding and/or fissioning as spread mec hanisms. Monodomous and polydomous nests did not show different aggression levels. Aggression behavior between nests was positively correlated with bo th spatial distance and intranest relatedness of recipient colonies, bur no t with genetic distance or intranest relatedness of donor colonies. Multipl e regression analysis revealed a stronger effect of spatial distance than o f genetics on aggression behavior in this study, indicating that the relati ve importance of environment and genetics can be variable in F. pratensis. Nevertheless, the positive regression between intranest relatedness of reci pient colonies and aggression in the multiple analysis supports earlier res ults that nestmate recognition is genetically influenced in F. pratensis an d further indicates that foreign label rejection most likely explains our d ata.