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ARS Home » Pacific West Area » Hilo, Hawaii » Daniel K. Inouye U.S. Pacific Basin Agricultural Research Center » Tropical Crop and Commodity Protection Research » Research » Publications at this Location » Publication #204129
Title: The Sterile Insect Technique and the Mediterranean Fruit Fly (Diptera: Tephritidae): Assessing the Utility of Aromatherapy in a Hawaiian Coffee Field

Author
item SHELLY, TODD - USDA-APHIS
item McInnis, Donald
item Rodd, Charles
item EDU, JAMES - USDA-APHIS
item PAHIO, ELAINE - USDA-APHIS

Submitted to: Journal of Economic Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/30/2006
Publication Date: 4/1/2007
Citation: Shelly, T.E., Mcinnis, D.O., Rodd, C.E., Edu, J., Pahio, E. 2007. The Sterile Insect Technique and the Mediterranean Fruit Fly (Diptera: Tephritidae): Assessing the Utility of Aromatherapy in a Hawaiian Coffee Field. Journal of Economic Entomology. 100:273-282.

Interpretive Summary: The Sterile Insect Technique (SIT) is widely used in integrated programs against tephritid fruit fly pests, particularly the Mediterranean fruit fly (medfly). One potential solution involves the pre-release exposure of males to particular attractants. In particular, exposure of male medflies to ginger root oil (GRO) has been shown to increase mating success in laboratory and field cage trials. Here, we describe a study of the effect of releasing sterile medfly males exposed to ginger root oil compared to unexposed males in a coffee field in Hawaii. Egg sterility was monitored weekly in the field comparing both sterile fly release areas and a control area containing no released flies. Results indicate that the exposure of ginger root oil had a significant effect in boosting the egg sterility and fly competitiveness of GRO exposed sterile males compared to unexposed males in the open field for the first time. These results indicate that GRO exposure to sterile males could significantly enhance the efficiency of sterile insect programs against this insect.

Technical Abstract: The Sterile Insect Technique (SIT) is widely used in integrated programs against tephritid fruit fly pests, particularly the Mediterranean fruit fly (medfly), Ceratitis capitata (Wiedemann). Unfortunately, the mass-rearing procedures inherent to the SIT often lead to a reduction in the mating ability of the released males. One potential solution involves the pre-release exposure of males to particular attractants. In particular, exposure of male medflies to ginger root oil (Zingiber officinale Roscoe; GRO) has been shown to increase mating success in laboratory and field cage trials. Here, we describe a field experiment that compares the level of egg sterility observed in two Hawaiian coffee plots, with GRO-exposed, sterile males released in one (treated) plot and non-exposed, sterile males released in the other (control plot). Once per week in both plots over a 13-wk period, sterile males were released, trap captures were scored to estimate relative abundance of sterile and wild males, and coffee berries were collected and dissected in the laboratory to estimate the incidence of unhatched (sterile) eggs. Data on wild fly abundance and the natural rate of egg hatch were also collected in a remote area that received no sterile males. Despite the fact that sterile:wild male ratios were significantly lower in the treated plot than in the control plot, the incidence of sterile eggs was significantly higher in the treated plot than in the control plot. Correspondingly, significantly higher values of Fried’s competitiveness index (C) were found, on average, for treated than control sterile males. This study is the first to demonstrate an association between the GRO ‘status’ of sterile males and the incidence of egg sterility in the field and suggests that pre-release, GRO-exposure may represent a simple and inexpensive means to increase the effectiveness of medfly SIT programs.