Behavior and chemical disguise of cuckoo ant Leptothorax kutteri in relation to its host Leptothorax acervorum

Females of the obligately parasitic cuckoo ant, Leptothorax kutteri, a workerless inquiline, are among the only adult ants that can successfully invade ant societies and come to be accepted as a nestmate by the existing adult workers. This occurs even though the cuckoo ant is usually severely attacked by the Leptothorax acervorum workers of the colony that she is attempting to enter and parasitize. Through extensive ethogram studies of established parasites and parasitized and free-living L. acervorum workers and queens, we show that the L. kutteri queen grooms host queens at an exceptionally high frequency. Possibly associated with this behavior, the established parasite is never attacked by the L. acervorum workers or queens she exploits. We show that there is exceptional similarity between the cuticular hydrocarbons and especially the cuticular fatty acids of the parasitic females and her nestmate L. acervorum workers, compared with nonnestmate workers and queens. We suggest that this matching of cuticular compounds may be associated with the grooming of host queens by the parasite. This in turn suggests the possibility that fatty acids have a role in colony-specific nestmate recognition in these and other ants and that grooming may serve for the dissemination of such substances throughout the colony