Foraging in the ant Camponotus mus: Nectar intake rate and crop filling depend on colony starvation

JOSENS, R; ROCES, F

JOURNAL OF INSECT PHYSIOLOGY

Elsevier

Año: 2000 vol. 46 p. 1103 - 1110

0022-1910

The effects of colony starvation on the dynamics of nectar collection were studied in individual workers of the ant Camponotus mus. A laboratory colony was first deprived of carbohydrates for 15 days, and thereafter fed daily ad libitum with diluted honey until satiation. During these two successive experimental phases, the probability of feeding, crop filling and fluid-intake rates were recorded daily for individual foragers collecting a 10% (w/w) sucrose solution. The feeding responses of individuals varied with the nutritional state of the colony. When the colony was deprived of sugar, acceptance of the sucrose solution was higher than under satiation. Feeding time increased with increasing starvation. During deprivation workers fed nearly continuously on the solution, whereas a number of feeding interruptions occurred under satiation. Crop filling also increased with increasing starvation, and showed a marked decrease when the colony was satiated. Fluid-intake rate during the deprivation phase was roughly twice that during the satiation phase. This matched well with the difference in sucking frequency recorded during ingestion in satiated and starved workers, which was also higher during starvation. Results indicate that the responsiveness of foragers, determined by the nutritional state of the colony, influenced both foraging decisions and the dynamics of fluid intake. Ó 2000 Elsevier Science Ltd. All rights reserved.