Dynamics of periodical cicada chorus centers (Homoptera: Cicadidae:Magicicada)

Mating aggregations of three species of periodical cicadas were monitored during the emergence of Brood XIX at a 16-ha study site in northwest Arkansas, May–June 1985. Magicicada tredecassiniappeared first and formed the most choruses. M. tredecimand M. tredeculachoruses formed next, and M. tredeculachoruses outnumbered those of M. tredecim.Of the 268 choruses seen, 84% were composed of M. tredecassini. M. tredecassiniwere often found chorusing in the same trees with the other two species. Such multispecies mating aggregations apparently are unique to periodical cicadas. Choruses were dynamic with respect to their locations and durations. Initially, choruses were located near areas of high cicada emergence densities. One week later, cicadas chorused in trees throughout the forest and at the forest edge. Many choruses were seen only once at a location. Although cicadas chorused for almost 4 weeks, individual choruses persisted only approximately 8 days, on average. Sound intensities under chorus centers ranged from 50 to 80 dh and were correlated with arena sizes during times of peak chorus activity. No distinct habitat preferences of the three species were observed, however, the tree species used by chorusing cicadas differed among the species.