Ant defense of Euphyonarthex phyllostoma (Homoptera : Tettigometridae) during trophobiotic associations

During a five-year field study, we made observations and conducted experime nts to demonstrate unequivocally that Euphyonarthex phyllostoma (Fulgoromor pha: Tettigometridae) is a myrmecophile. isolated adults and colonies alway s were found in association with ants. Colonies were associated only with C amponotus brutus or C. acvapimensis (Formicinae), whereas isolated adults w ere attended by ants belonging to several species of Formicinae, Dolichoder inae, and Myrmicinae. The size of the planthopper colonies reached higher l evels when attended by C. brutus than by C acvapimensis. Experiments using ant exclusion showed that both ant species protected egg masses against par asitic wasps, but egg masses were less parasitized on trees occupied by C. brutus than on those occupied by C. acvapimensis (P = 0.0052). The producti on of egg masses by female hoppers was recorded only when C. brutus, C. aev apimensis, or the myrmicine ant Myrmicaria opaciventris attended the hopper . In both former cases, the presence of ants influenced the aggregation of the nymphs as they dispersed when ants were excluded. The aggregation of th e nymphs ensured that they were properly attended. Parental care by the fem ales was reduced tu their presence above ur close to the egg masses. in fac t, specialized workers of the attending ant species protected the egg masse s as well as nymphs.