LATITUDINAL VARIATION IN COLD-HARDINESS AND BODY-SIZE IN THE BOREAL ANT SPECIES LEPTOTHORAX-ACERVORUM (HYMENOPTERA, FORMICIDAE)

The Myrmicinae species Leptothorax acevorum (Fabricius 1793) is among the ants ranging farthest north in both North America and Eurasia. Wor kers from 3 populations living in areas with greatly different climate s differ in cold hardiness and individual size. Workers from Cape Kind o on the share of the White Sea (66 degrees 33' N) survived best at to w temperatures and were significantly larger than workers from Nurnber g Reichswald (49.5 degrees N), with workers from the St. Petersburg ar ea (60 degrees N) lying between the two extremes. The significance of the findings is discussed.