Jm. Herbers et Vs. Banschbach, FOOD-SUPPLY AND REPRODUCTIVE ALLOCATION IN FOREST ANTS - REPEATED EXPERIMENTS GIVE DIFFERENT RESULTS, Oikos, 83(1), 1998, pp. 145-151
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.