Submitted to: Journal of Economic Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/1/2004
Publication Date: 6/10/2004
Citation: Shelly, T.E., McInnis, D.O., Pahio, E., Edu, J. 2004. Aromatherapy in the mediterranean fruit fly (diptera: tephritidae): sterile males exposed to ginger root oil in pre-release, storage boxes display increased mating competitiveness in field cage trials. Journal of Economic Entomology. 97: 846-853.
Interpretive Summary: The use of an aromatic chemical to increase the mating ability of Mediterranean fruit flies (medflies) has been investigated in Hawaii and found to be significant. The aromatic compound, ginger root oil, has been demonstrated to be effective in raising the mating ability of medfly males ca. 2-3 fold in outdoor field cage mating tests. This rise in ability even has come from the mere exposure of the aroma to the males for a few hours as young adults. The current experiment investigated the effectiveness of using the standard adult fly containers ( ca. 35,000 pupae/box) for conducting the fly exposures prior to fly release in the field. We found that exposing the flies as adults significantly improved mating ability at doses of ginger oil/box up to 2mls, but not at 2 mls. Exposing the insects as pupae then as adults by placing the aroma prior to fly emergence resulted in increased mating ability after using 1.0 mls but not at o.25 mls/box. These results confirm the previous work about the effectiveness of using ginger root oil as a mating stimulant for medfly males in SIT programs, and have demonstrated the usefulness of standard large–scale holding containers in adequately treating male flies prior to release.
Technical Abstract: Previous research showed that exposure to ginger root, Zingiber officinale Roscoe, oil increased the mating success of mass-reared, sterile males of the Mediterranean fruit fly, Ceratitis capitata (Wiedemann). This work, however, involved the exposure of small groups of males (n = 25) in small containers (volume 400 ml). Several sterile male release programs use plastic adult rearing containers (so-called PARC boxes; hereafter termed storage boxes; 0.48 by 0.60 by 0.33 m) to hold mature pupae and newly emerged adults before release (36,000 flies per box). The objective of the current study was to determine whether the application of ginger root oil to individual storage boxes increases the mating competitiveness of sterile C. capitata males. Irradiated pupae were placed in storage boxes 2 d before adult emergence, and in the initial experiment (adult exposure) ginger root oil was applied 5 d later (i.e., 3 d after peak adult emergence) for 24 h at doses of 0.0625, 0.25, 0.5, 1.0, and 2.0 ml. In a second experiment (pupal-adult exposure), ginger root oil was applied to storage boxes immediately after pupal placement and left for 6 d (i.e., 4 d after peak adult emergence) at doses of 0.25 and 1.0 ml. Using field cages, we conducted mating trials in which ginger root oil-exposed (treated) or nonexposed (control) sterile males competed against wild-like males for copulations with wild-like females. After adult exposure, treated males had significantly higher mating success than control males for all doses of ginger root oil, except 2.0 ml. After pupal-adult exposure, treated males had a significantly higher mating success than control males for the 1.0-ml but not the 0.25-ml dose of ginger root oil. The results suggest that ginger root oil can be used in conjunction with prerelease, storage boxes to increase the effectiveness of sterile insect release programs.