Biometric Comparison of Body Size between Queens and Workers in New Guinean Swarm-founding Ropalidia

Abstract

Body size was compared between queens and workers in two New Guinean swarmfoudning Ropalidia species, R. bambusae and R. leopoldi. Queens of R. bambusae tended to have longer mesosoma and larger metasoma than workers. Although the canonical discriminant analysis using nine morphological characters showed that there was only partial overlap between queens and workers, respective characters of them overlapped considerably if compared separately. Queen/worker size ratio within a colony for the mesosomal length was 1.02, which was smaller than inter-colonial difference. Although only one queen and seven workers were available for R. leopoldi, there seem to be distinct size dimorphism in this species. Queen/worker size ratio for mesosomallength was 1.16, and this value was comparable to that in R. montana, which has been known to represent distinct female caste dimorphism.