LAUSR

Abstract Fruits of Miconia calvescens DC. (Melastomataceae) were dissected to study insect frugivory in this plant in its native habitat in Costa Rica. Larvae of an unknown Mompha species (Lepidoptera: Momphidae), Anthonomus monostigma Champion (Coleoptera: Curculionidae), and unidentified Diptera and Hymenoptera were found in M. calvescens fruits. The Mompha species, described here as new as Mompha luteofascia Koster & Badenes-Pérez, was the most abundant insect frugivore in M. calvescens, infesting up to 38.1% of the fruits sampled. Feeding damage by M. luteofascia was positively correlated with fruit maturity, and resulted in significantly reduced numbers of seeds and rates of seed germination. Miconia calvescens fruits with medium damage (50–75% of the pulp missing) and high damage (75–100% of the pulp missing) had an average of 96 and 99 seeds, respectively, whereas undamaged fruits contained an average of 127 seeds per fruit. In fruits with medium and high fruit damage, only 1.9 and 0.1% of the seeds germinated, respectively, whereas 34.8% of the seeds germinated in undamaged fruits. Mompha luteofascia developed through three instars, as determined from measurement of head capsules. Larvae usually fed as one individual per each fruit attacked, exiting fruit to pupate in foliage or litter. Parasitism of M. luteofascia larvae was substantial, averaging 64 and 38% at the two study sites. Although host specificity of M. luteofascia has not been evaluated, the significant reductions in seed numbers and seed germination caused by its larvae indicate that this species deserves further assessment as a potential biological control agent of M. calvescens.