FOOD-SUPPLY AND REPRODUCTIVE ALLOCATION IN FOREST ANTS - REPEATED EXPERIMENTS GIVE DIFFERENT RESULTS

We studied food limitation as a proximate determinant of resource allo cation in social insect colonies by repeating a held experiment that h ad previously produced negative results. A series of plots was supplem ented with food in Vermont, USA, and others were left as controls. Aft er two years of the food supplementation, all plots were excavated and nests of Leptothorax longispinosus ants were collected. We found sign ificant effects of the food treatment on reproductive output, male all ocation ratios, and the proportion of biomass allocated to reproductio n versus growth. These results contradict a previous study on the same population of these ants, and we attribute the different outcomes to annual variation in the selective regime experienced by the ants. Thus interpretation of field experiments should be couched in terms of the ir temporal dimensions.