Chemical communication among workers of the fire ant Solenopsis saevissima (Fr. Smith) 3. The experimental induction of social responses

Abstract

1. 1. The following categories of social behaviour among fire ant workers are known to be mediated principally by chemical releasers: recruitment in mass-foraging, recruitment in colony emigration, alarm, grooming, and elementary attraction leading to clustering. Each behaviour pattern can be induced, wholly or in part, by the experimental presentation of chemical substances removed from the bodies of the workers. 2. 2. Colony emigration is organized by odour trails in a manner nearly identical to that employed in mass-foraging. Incipient emigration has been induced with massive doses of extracted trail substance. 3. 3. Alarm behaviour is released principally by a volatile cephalic substance and intensified secondarily by the attractant component of Dufour's gland secretion. 4. 4. Grooming behaviour is characterized as glossal licking of objects unaccompanied by trail-laying. It has been induced artificially with certain fractions of fat-soluble extracts made from whole worker bodies. 5. 5. Workers separated from the nest can be induced to orient toward the air removed from around other groups of workers. Indirect evidence has been obtained that one or more simple gaseous excretory products are adequate to produce the response. Carbon dioxide has been used to produce it artificially.