Solar sterilization of abscised fruit: A cultural practice to reduce infestations of Anastrepha obliqua around orchards

Abstract

Abscised mangoes, Manguera indica, of several cultivars were stored under varying conditions: no sun (stored in a laboratory), shade (stored under the shade of a mango tree), full sun (stored in direct view of the sun), and covered with a black plastic bag and stored in direct view of the sun.The numbers of living Anastrepha obliqua larvae emerging from each treatment were compared and internal temperatures of the mangoes in the various storage regimes recorded. Mangoes stored in the laboratory almost always produced more larvae than mangoes stored under the other regimes, even though internal temperatures of mangoes stored in shade were not much higher than those of mangoes stored in the laboratory. Internal temperatures of mangoes stored under black plastic garbage bags in full sun consistently reached temperatures fatal to A. obliqua and other Tephritidae. Nonetheless, mortality was not consistently higher in these treatments than in the treatments stored in the shade. We suspect that cloudy weather reduced the internal temperatures of the mangoes to sufficiently tolerable levels for larval survival. Removing abscised mangoes from the shade of the tree may reduce infestations on the arid side of the island, where sunny days are more common. Our research suggests that removing abscised fruit from the shade of backyard trees, along with other strategies, may be useful in establishing a fruit flyfree zone.