Ecdysone Antagonizes Growth and Juvenile Hormone-Dependent Soldier Caste Identity in Camponotus floridanus

Ecdysone negatively regulates size and blocks soldier determination in the ant Camponotus floridanus, extending developmental timing during the worker–soldier switchpoint window.

• Why it matters: Ant caste development depends on juvenile hormone, but ecdysone’s role in shaping caste identity and how it interacts with JH is poorly understood.
• What they did: The authors manipulated ecdysone during the worker–soldier switchpoint sensitivity window and measured head/body size, head-to-body allometry, and developmental timing; they also assessed ecdysone synthesis, degradation, and signaling reception in developing soldiers.
• The result: JH and ecdysone antagonize each other at molecular and phenotypic levels, and ecdysone signaling is negatively regulated by temperature, implying a hormone–environment mechanism for ant size and caste plasticity.