The Inflated Calyx of Physalis angulata: A Refuge from Parasitism for Heliothis subflexa

Abstract

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Behavioral Adaptations Increase the Value of Enemy-Free Space for Heliothis Subflexa, a Specialist Herbivore

“…Although many species of Physalis are acceptable to H. subflexa, larvae are commonly found on P. angulata (referred to here as Physalis ;Laster 1972;Yepez et al 1990;Sisterson and Gould 1999), and we used this species for all experiments. Physalis plants were grown from seeds collected in Orangeburg County, South Carolina, in 1997.…”

“…Larvae should therefore seek refuge either before feeding or as quickly as possible after starting to feed. Sisterson and Gould (1999) demonstrated the importance of a structural refuge in protecting H. subflexa on Physalis from parasitoids. By cutting off the bottom of the lantern to allow natural enemies free access to larvae feeding on Physalis fruits, they eliminated the structural refuge.…”

“…Physalis plants produce fruits enclosed within a thin-walled, inflated calyx (referred to herein as a ''lantern''). When feeding on Physalis fruits within this lantern, H. subflexa larvae are protected from some natural enemies (Sisterson and Gould 1999). Heliothis virescens, by contrast, is an extreme generalist, feeding on 37 species of plants in at least 14 families (Sheck and Gould 1993), including tobacco, cotton, soybean, and other crops of agricultural importance.…”

Primer registro de <i>Chloridea (Heliothis) subflexa</i> (Lepidoptera: Noctuidae: Heliothinae) en uchuva en Brasil

“…The rates of parasitism are very low (1 to 4%) (Sisterson and Gould, 1999;Oppenheim and Gould, 2002a;Oppenheim and Gould, 2002b) and are not only related to the presence of the calyx.…”

“…The calyx provides an enclosure for the larvae, creating a structural refuge that reduces its detection by parasitoids and predators (Baumann and Meier, 1993;Sisterson and Gould, 1999;Oppenheim and Gould, 2002a). This structure acts as a mechanical barrier and has withanolides and glycosides that are feed deterrents (Baumann and Meier, 1993;Dinan et al, 1997) for other phytophagous insects.…”