ASSOCIATION BETWEEN THE SHRUB CAPPARIS-RE TUSA (CAPPARIDACEAE) AND THE ANTS CAMPONOTUS-BLANDUS AND ACROMYRMEX-STRIATUS (HYMENOPTERA, FORMICIDAE)

The hypothesis that the nectivore ant Camponotus blandus operates as a n alternative defense of the shrub Capparis retusa against the leaf-cu tting ant Acromyrmex striatus was tested. Dat, were obtained in a fore st reserve of the Argentinean subtropical dry Chaco (25-degrees 55' S, 62-degrees 05' W) during the spring of 1986. C. retusa is abundant, b ut it is not a part of the leaf-cutting ant diet (< 1%), has a high pr oportion of nectivore ant visits, and low levels of chemical and physi cal defenses. Shrubs without C. blandus were intensively harvested by A. striatus, which suggests that the nectivore ant is an alternative d efense for the shrub against the leaf-cutting ant.