EFFECT OF GERSTAECKERIA BIFASCIATA (GERSTAECKER, 1860) (COLEOPTERA: CURCULIONIDAE: CRYPTORHYNCHINAE) HERBIVORY ON A GLOBOSE CACTUS IN GUANAJUATO, MEXICO

This is the first scientific report of the behavior of adult Gerstaeckeria bifasciata (Gerstaecker, 1860) and the damage they cause on the globose cactus Stenocactus obvallatus (DC.) A. Berger ex A.W. Hill (Cactaceae). During 2017, we surveyed a population of S. obvallatus (N = 337 plants) in Tierra Blanca, Guanajuato, Mexico, recording the damage that they presented in their stems. A year later, a second survey was carried out, recording survival or death of the plants. Although 86% of plants showed ribs damaged by this weevil in the first census, only a small percentage of them died (5.64%). Our study suggests that S. obvallatus has evolved mechanisms that allow it to tolerate herbivory by this weevil, as we recorded G. bifasciata adults feeding from both caulinary (ribs) and reproductive structures (floral buds and flowers) of S. obvallatus.