RELATIONSHIPS BETWEEN ANTS (HYMENOPTERA, FORMICIDAE) AND EUPHYONARTHEX PHYLLOSTOMA (HEMIPTERA, TETTIGOMETRIDAE)

During a five-year field study we noted that Euphyonarthexphyllostoma (Fulgoromorpha, Tettigometridae) was always associated with plants of the genus Bridelia (Euphorbiaceae), particularly with B. micrantha. Mo reover, we gathered arguments permitting us to unequivocally demonstra te that this plant hopper is a myrmecophile. Isolated adults were atte nded by ants belonging to 17 species and three subfamilies, while colo nies were only associated with Camponotus brutus or C. acvapimensis (F ormicinae). The behavior of the workers of C. brutus during the solici tation of honeydew was studied in detail. The position of the workers varies as a function of the size of the nymphs of the hopper. The work ers place themselves at the side of clusters of small first instar nym phs, moving their antennae slowly above the nymphs. The workers antenn ate the extremity of the abdomen of the nymphs which begin to produce honeydew. This antennation continues during the entire period of honey dew excretion. In contrast, generally only one worker attends one last instar nymph or one adult and places itself behind the hopper. The wo rker antennates the dorsal regions of the abdomen and the thorax of th e hopper in broad prolonged movements. A hopper ready to secrete honey dew raises its body: in response, the worker folds back the antennae a nd palpates the apex of the hopper's abdomen, all the while absorbing the excreted droplets. If an attending worker is not in the proper pos ition when the hopper is ready to excrete honeydew, the latter attract s the ant by alternating the extrusion and withdrawal of the first dro plet. All other arboreal ant species tested under laboratory condition s (B. micrantha cultivated in planters) were able to get honeydew from both adults and nymphs, even those not recorded as being associated w ith the hopper in nature. Behavior varied with the workers' size, but the same body areas of the hopper were palpated.