REMOVAL RATES OF SEEDS OF 5 MYRMECOCHOROUS PLANTS BY THE ANT FORMICA-POLYCTENA (HYMENOPTERA, FORMICIDAE)

Attractiveness of five deciduous forest myrmecochorous and diplochorous plants for Formica polyctena ants were studied in field experiments. Seeds of different plant species were removed at different rates (RRS) by ants. Experiments with demonstrations of seeds of one or a pair of species and with partly cut elaiosomata or seed bodies showed that seed attractiveness increased with seed size increase in Viola matutina, Chelidonium majus, V. mirabilis, V. hirta and Asarum europaeum, and was weakly correlated with elaiosome size. The exponential character of RRS from groups was especially pronounced for pure myrmecochors The RRS obtained for F. polyctena near (5 m) were about ten times shorter than those obtained far (15 m) from the nests. Ants taking seeds of A. europaeum, V. hirta and V. mirabilis were significantly larger than ants taking Ch. majus. It is suggested, that in habitats with colonies of F. polyctena with a prevalence of small individuals, the small-seed myrmecochors receive some advantages in seed dispersal, and in habitats with colonies with a prevalence of large size classes - the large-seed myrmecochors have an advantage.