DO ANTS CONTROL GALL MIDGES IN NEOTROPICAL CANOPIES?
The authors studied two canopies of the widely distributed Amazonian tree, Goupia glabra Aubl. (Celastraceae), at heights of 38 m and 45 m near Manaus, Brazil. They fogged the trees with 1% natural pyrethrum at intervals of 6 or 24 months from 1991 to 1994. Although a total of 95 ant species occurred on a single tree, Hymenoptera (mostly Formicidae) and Diptera dominated. Most ants were foraging permanently in the canopy, and their recolonization after fogging seemed to follow stochastic pathways. The capture data indicated a biotic interaction primarily between predating ants and gall midges (Cecidomyiidae) and secondarily between gall midges and the parasitic Hymenoptera. Data from tree canopies of a lowland floodplain forest on Borneo obtained by Stork in 1991 suggest that a low number of ant species might result in a reduced predation of Cecidomyiidae galls by ants, which favors an interaction primarily between the parasitic Hymenoptera and the gall midges. ANHUF, DIETER, Geographi
