Colony productivity of the paper wasp Polistes snelleni: Comparison between cool-temperate and warm-temperate populations

Production characteristics, including colony productivity, labor efficiency and sex ratio, in the paper wasp Polistes snelleni were compared between cool-temperate (Hokkaido, northern Japan) and warm-temperate (Nagano and Kanto, central Japan) populations, based on examination of old nests. The production schedule of P. snelleni was protandrous. Numbers of workers, males and gynes produced per colony were all larger in the warm-temperate populations. The numbers of reproductives (males plus gynes) per worker were generally greater in cool-temperate than in warm-temperate colonies, although some extraordinarily large warm-temperate nests had very high gynes/worker ratios. The number of males was not significantly correlated with the number of workers in either cool-temperate or warm-temperate populations. Differences in the production characteristics between populations are discussed in terms of climatic conditions, a major factor in differences in the length of the nesting period. The production of reproductives in very large warm-temperate nests is discussed in relation to worker reproduction.