PREDATION OF THE STABLE FLY Stomoxys calcitrans BY THE MEZQUITE SPINY LIZARD Sceloporus grammicus ON CATTLE IN AGUASCALIENTES, MEXICO: A SYMBIOTIC RELATIONSHIP OF MUTUALISM?

Abstract

We document an unusual behavior in a population of the Mesquite Spiny Lizard Sceloporus grammicus in the municipality of Rincon de Romos, Aguascalientes, Mexico. On approximately 30 occasions we were able to observe and photo-document some individuals of this lizard jumping onto the backs and extremities of cattle when they lay down near the trees. Evidently, this behavior is aimed at predating on the Stable Flies Stomoxys calcitrans, which have been documented to alight on cattle to feed on their blood. The interesting thing is that Mesquite Spiny Lizards could inadvertently function as a biological control that would help cattle get rid of some bites and potential diseases. However, cattle frequently attempted to pull the lizards by making movements with their back muscles or trying to scare them away by making agitated movements with their tails.