Nectar feeding by the ant Camponotus mus: decision-making process during foraging for different body sizes.

MEDAN, VIOLETA; JOSENS, ROXANA

Touluse

Congreso; 2002 Meeting of the IUSSI; 2002

International Union of Study of Social Insects

The nectivorous ant Camponotus mus shows a broadsize variation within the worker caste. Large ants can ingest faster andlargerloads than small ones. Differences in physiological abilities in fluid ingestion due to the insect size could be related to differences indecision-making according to ant size during nectar foraging. Sucrose solutions of different levels of sugar concentration (30% or60%w/w), viscosity (high or low) or flow rate (adlibitum or 1 ml/min) were offeredin combination to analyse the behaviouralresponses to each of these properties separately. Differences were found depending on ant body size and the property compared. Aregulated flow produced smaller crop loads for medium and large ants compared to the same solution given ad libitum. All foragersremained longer times feeding at the regulated flow source but larger ants often made longer interruptions. When sugarconcentration was constant but viscosity was high, only large ants increased feeding time. Constant viscosity with different sugarconcentration determined longer feeding time and bigger loads for the most concentrated solution for small but not for large ants.Small ants reached similar crop loads in a variety of conditions while large ants did not. These differences could be evidence of apossible specialization for nectar foraging basedon ant body size.