The 'Hippie Ant' - A case of extreme intranidal polymorphism in Fennoscandian Formica lugubris

摘要

An extremely hairy form, frequently suspected to represent a separate species, occurs within the Fermoscandian population of Formica lugubris Zetterstedt 1838 (Hymenoptera: Formicidae). This form was known under the working name "Hippie Ant" among Finnish wood ant students. Results of a discriminant analysis and the consideration of intranidal phenotype compositions provide a high probability that the "Hippie Ant" is only a morph of F. lugubris but no social parasite or independent species living in parabiosis with F. lugubris. The analysis included a standardized morphometry of 9 characters, removal of allometrically-caused variance, cluster analysis and canonical discriminant analysis. A three-morph model, assuming the existence of a normal (M1), intermediate (M2) and very hairy "Hippie Ant" morph (M3) provided a better description of the data than a two-morph model that assumes the existence of only M1 and M3.38% of the 74 Fermoscandian nest samples contained morph mixtures of varying composition and 62 % M1 exclusively. 25 % of the 20 nests with M3 contained only M3 but 75 % also other morphs. No polymorphism was found within 73 nest samples from Britain, Germany, Czechoslovakia, the Alps, the Balkans and Russia where only the normal morph M I was present.