Pre-dispersal predation in three Quercus species from the Ajusco piedmont, Mexico

Abstract

Pre-dispersal acorn predation is performed by weevils of the family Curculionidae (Coleoptera) and moths of the genus Cydia (Lepidoptera: Tortricidae). Previous studies have shown that weevils select large acorns, and the occurrence of more than one larva in a single acorn (superinfestation), but seed predation by moths has received less attention, and no studies of curculionid and moth preferences for different coexisting oak species have been performed. Here, we analyzed pre-dispersal acorn predation by curculionids and moths in 3 oak species (Quercus) from the Ajusco volcano foothill and its relation to seed size. Acorn predation was higher in the largest-seeded species, Q. obtusata, and lower in the species having the smallest acorns, Q. castanea. Oak species explained the proportions of acorns preyed upon by curculionids or moths; the one performed only by curculionids was high and similar in Q. obtusata and Q. rugosa and lower in Q. castanea, but the later species had a significantly higher proportion of only moth-preyed acorns. Superinfestation was higher in Q. obtusata and lower in Q. rugosa and Q. castanea. This is the first evaluation of curculionid and moth predation and preferences in a group of coexisting oaks.