Apple Maggot (Diptera: Tephritidae) Trap Enhancement with Washed Bacterial Cells

Abstract

Six apple maggot, Rhagoletis pomonella (Walsh), trap designs were evaluated in both managed and abandoned orchards. On the basis of trap efficacy, a protocol was developed for a control strategy using the Ladd trap (red hemispheres on a yellow rectangle) baited with apple volatiles, for which captures on red were consistently greater than on yellow. In another study, washed bacterial cells (media washed from the culture, and cells suspended in distilled water) of Enterobacter agglomerans removed from adult apple maggot and placed onto Ladd traps had significantly greater captures than did traps with washed cells from a standard culture or with ammonium acetate. The control strategy using the same protocol was also evaluated using the Ladd trap baited with apple volatiles and washed bacterial cells. There was a significant increase in the capture of gravid females on yellow surfaces and no detectable injury from the apple maggot at harvest. Fruit treated weekly in the field with an antibiotic mixture of streptomycin and rifampicin significantly reduced fruit injury indicating that the bacterium may serve some essential nutritional or biological need.