Fruit flies (diptera: tephritidae) infesting fruits of the genus Psidium (Myrtaceae) and their altitudinal distribution in western Venezuela

A survey of fruit flies infesting Psidium fruits was conducted in western Venezuela from June 1992 through December 1995. Of 201 fruit samples collected from 139 localities at altitudes between sea level and 2,000 m, four species of Psidium plants were found in the western region of Venezuela. These were P. guajava L. (10-1930 m), P. guineense Sw. (100-1950 m), P. caudatum McVaugh (1800-1950 m) and P. friedrichsthalianum (Berg) Niedenzu (35-1700 m). Four tephritid fly species were reared: Anastrepha striata Schiner, A. fraterculus (Wiedemann), A. obliqua (Macquart), and Ceratitis capitata (Wiedemann). All four fruit fly species emerged from P. guajava. A. striata was the most common on P. guajava, P. guineense and P. friedrichsthalianum, with an infestation range of 96.1%-97.0%. P. caudatum was more frequently infested by A. fraterculus (94.5% adults emergence); the plant's distribution was restricted to highlands. Observations on the altitudinal distribution of A. striata on P. guajava showed that the highest infestation (253.9 adults/kg fruits) occurred at about 1,000 m. The infestation rate of P. guajava by A. fraterculus and A. obliqua varied with elevation. In low elevation areas (0-1,200 m), A. obliqua was found more frequently than A, fraterculus, whereas A, fraterculus was found more frequently than A. obliqua in high altitude areas (1,201-2,000 m). C. capitata was erratically encountered in this study.