NESTMATE RECOGNITION IN 3 SPECIES OF STENOGASTRINE WASPS (HYMENOPTERA, VESPIDAE)

The capacity to recognise a conspecific intruder was investigated in P arischnogaster jacobsoni, Liostenogaster flavolineata and L. vechti, t hree species of primitively social wasps of the subfamily Stenogastrin ae. Results of behavioural experiments carried out in the field showed that females of all three species react pacifically if presented with female nestmates, but aggressively reject an intruder from a conspeci fic colony. As L. flavolineata and L. vechti both build large clusters of nests, often very close to each other, the recognition capacity am ong females from different nests, but in the same conspecific cluster, was also investigated. Females of both species were more aggressive t owards females from a different colony in the same cluster than toward s their female nestmates. Additional experiments on L. flavolineata sh owed that there was no difference in reaction towards females from col onies nearer or further from the tested colony but within the same clu ster, nor towards females from a different cluster. The capacity to re cognise an alien conspecific nest containing immature brood was invest igated in P. jacobsoni. Adult females of this species, invited to land on an alien nest which had experimentally been exchanged for their ow n, accepted the new nest and partially destroyed the immature brood. T he behaviour of the females when they land on an alien nest, however, suggests that they do recognise the nest as foreign. Acceptance of for eign nests coupled with low immature brood destruction is probably due to the high energetic costs of egg-deposition and larval rearing in s tenogastrine wasps. These results suggest that nestmate recognition in these wasps is very efficient, even though they belong to the most pr imitive subfamily of social wasps.