Capture of oriental fruit flies (Diptera : Tephritidae) by protein-baited traps and fruit-mimicking visual traps in a guava orchard

Experiments were conducted to compare the effectiveness of 2 commercially a vailable traps, the protein-baited Mcphail trap and the fruit-mimicking Lad d trap, for capturing oriental fruit flies, Bactrocera dorsalis Hendel, in a commercial guava orchard. The relative attractiveness of McPhail and Ladd traps changed over seasons. In the winter of 1996. Ladd traps captured mor e females than McPhail traps. In the spring of 1997, McPhail traps captured > 4 times as many females as Ladd traps. In the summer, fall, and winter o f 1997, equal numbers of females were captured on Ladd and McPhail traps, a nd in the spring of 1998, McPhail traps captured >10 times as many females as Ladd traps. Ovaries of female fruit flies captured in these 2 traps were dissected and examined for the presence of mature eggs. Greater numbers of immature females were captured in McPhail traps than on Ladd traps in both 1997 and 1998. In 1997, the proportion of immature versus mature females c aptured in both trap types changed over seasons, with the greatest proporti on of immature females being captured in the spring. We conclude that McPha il traps are a better option for growers than Ladd traps, especially in the spring when the proportion of protein-hungry flies may be greater.