Evidence for an Alarm Pheromone in Ropalidia romandi (Le Guillou) (Hymenoptera: Vespidae)

Abstract

In an Australian swarm‐founding polistine, Ropalidia romandi, exposure of squashed venom sacs of workers outside the nest reduced the threshold for attack. This treatment induced recruitment of several workers to the outer surface of the envelope, while a physical stimulus given to the nest caused a sudden emergence of a large number of workers from the nest. Visual cues induced attack; black objects were preferentially attacked by the wasps while white ones were rarely attacked. Copyright © 1994, Wiley Blackwell. All rights reserved