The Hymenopterous Poison Apparatus. X. Morphological and Behavioral Changes in Atta texana (Hymenoptera: Formicidae)
Atta texana (Buckley) and other members of this genus no longer utilize the 8th and 9th gonapophyses as part of their defensive system. Although the sclerites that comprise the stinging apparatus in most aculeate Hymenoptera are present in the species, they seem to function only in the deposition of trail pheromones. A mechanical and chemical defense, through the utilization of a sting and associated venom components, has been replaced in attines by a new mechanical defensive system, primarily the powerful mandibles. The morphology of structures responsible for the deposition of trail pheromones is discussed along with new means of defense and associated behavioral characteristics.