S. Nakagawa

VISUAL ORIENTATION OF CERATITIS CAPITATA FLIES TO FRUIT MODELS

Wooden and rubber fruit models of different shapes, colors, and sizes were hung in fruiting coffee trees. Spheres (7.5 cm in diam) were much more attractive to Ceratitis capitata (Wiedemann) than cubes, cylinders, or rectangles of equivalent surface area. Black and yellow were the most attractive of eight colors, and white and grey were the least attractive. When an array of sphere sizes were tested, the attraction to flies increased as the size of yellow spheres increased from 1.5 to 18 cm diam. Trimedlure (tert‐butyl 4(5)‐chloro‐2‐methylcyclohexanecarboxylate) enhanced the attraction for males when added to 20.3 times 25.4‐cm yellow rectangles and to 7.5‐cm black spheres.

Mediterranean fruit fly1/: Laboratory and field evaluations of synthetic sex pheromones2/

Abstract Fifteen acids present in the natural sex pheromones produced by male Mediterranean fruit flies, Ceratitis capitata (Wiedemann), were separated by gas‐liquid chromatography and identified. Then combinations of the acids and of previously identified pheromones were bioassayed for attraction to virgin female Mediterranean fruit flies in an outdoor olfactometer. However, when 2 of the most promising combinations were tested in the field, they attracted large numbers of males, but no females. In the laboratory, females reared from fruit infested in the field responded to the synthetic pheromone. No explanation is available for these anomalous results.