Nectar feeding and body size in the ant Camponotus mus

Summary: Feeding behavior and worker polymorphism were studied in the ant Camponotus mus. Individual workers were conditioned to visit an arena in which an ad libitum food source of 60% (w/w) sucrose solution was offered. Individual feeding time, crop load, and intake rate were recorded. Worker head width and pronotum width were measured. Behavioral and morphometric variables were analyzed in relation to ant weight. C. mus workers of the laboratory nest have an elemental polymorphism with monophasic allometric growth. Worker size affected feeding dynamics. Load weight and intake rate were positively correlated with ant weight, whereas feeding time was independent of ant weight. Size related differences in intake rate could not be attributed to differences in pumping frequency, and could be attributed to differences in the volume ingested per pumping cycle.