COLONY DEFENSE AGAINST ANTS IN VESPA

On Ishigaki Island in southern Japan, despite the prevalence of ants in the study area, none of the failures of 54 Vespa affinis (L.) colonies located could be directly attributed to attacks from ants. The long vestibule of the V. affinis embryo nest was not effective in preventing access to the nest by small species of ants. V. affinis and V. tropica (L.) females produce a substance which is repellent to ants. The substance is produced by the 6th and 7th abdominal sternal glands and is thought to be applied to the embryo nest petiole via the sternal brush. As the substance is produced by workers and queens during the entire life of the colony, it probably has a dual function.