Queens control caste allocation in the ant Cardiocondyla obscurior

Area of Science:

• * Social insect behavior and reproductive conflict.
• * Evolutionary biology and caste determination.

Background:

• * Reproductive conflict can arise in social insects when queens and workers have differing fitness optima.
• * Previous research indicates queen control over sex allocation in some species.

Purpose of the Study:

• * To investigate queen control over caste allocation in the ant Cardiocondyla obscurior.
• * To identify traits that differentiate queen and worker castes during development.

Main Methods:

• * Observation of caste differentiation in Cardiocondyla obscurior from the egg stage.
• * Comparative analysis of queen- and worker-destined eggs and larvae, including size, weight, morphology, and cuticular odors.
• * Behavioral assays of adult worker interactions with developing larvae.

Main Results:

• * Crystalline deposits were identified as a discrete trait distinguishing castes from the egg stage onwards.
• * Size and weight differences were observed in late-stage queen and worker larvae, but not in hair morphology or cuticular odors.
• * Adult workers treated developing queens and workers indiscriminately.

Conclusions:

• * Queens possess control over queen-worker caste allocation in Cardiocondyla obscurior.
• * The findings suggest aligned fitness interests for optimal resource allocation within the colony.
• * Crystalline deposits represent a novel marker for ant caste identification during pre-imaginal development.