The inflated calyx of Physalis angulata: A refuge from parasitism for Heliothis subflexa

Heliothis subflexa and H. virescens are the only known hosts of the parasit oid Cardiochiles nigriceps. H. subflexa, a specialist on plants in the genu s Physalis, appears to have a lower parasitism rate compared to the polypha gous H. virescens. Physalis is characterized by producing fruits that are c oncealed within a paper-like lantern, within which H. subflexa larvae feed. We conducted an experiment to determine whether H. subflexa is protected f rom parasitism by feeding within the lanterns of Physalis. We compared para sitism rates of wild H. subflexa larvae on normal P. angulata plants to par asitism rates of larvae on plants that had the tips of all the lanterns rem oved to allow parasitoids access to the larvae. A higher percentage of larv ae were parasitized on plants with cut lanterns (48.25%) than uncut lantern s (6.74%). A second experiment was conducted to determine whether volatiles released from cut lanterns influenced the searching of C. nigriceps. This experiment consisted of the two treatments from the previous experiment and a third in which the tips of lanterns were removed and the resulting hole was stapled shut. Cutting plants did not make the plants more attractive to searching parasitoids. We conclude that H. subflexa gains protection from parasitism by feeding within the inflated calyx of Physalis.