Influence of the odour of fruit, yeast and cue‐lure on the flight activity of the Queensland fruit fly, Bactrocera tryoni (Froggatt) (Diptera: Tephritidae)

Certain volatile substances increased the frequency of flights by Bactrocera tryoni (Froggatt) in laboratory arenas with artificial foliage, irrespective of the presence or absence of a visual cue (red fruit model). The odour of guava and iso‐amyl acetate, but not nerol, increased the flight frequency of mature females. The odour of yeast autolysate had a similar effect on immature females (previously starved of the substance), but had no effect on mature females (previously fed on it). The flight activity of mature males increased in the presence of the odour of cue‐lure. Ten per cent of flies landed on a red model within 7.5 min when in the presence of an odour, whereas only 1.7% did so when there was no odour. No flies landed on transparent models regardless of the presence or absence of odour.