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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 #182317
Title: THE STERILE INSECT TECHNIQUE AND THE MEDITERRANEAN FRUIT FLY: ASSESSING THE UTILITY OF AROMATHERAPY IN LARGE FIELD ENCLOSURES

Author
item SHELLY, T - APHIS
item McInnis, Donald
item RENDON, P - APHIS, GUATEMALA

Submitted to: Entomologia Experimentalis et Applicata
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/20/2005
Publication Date: 8/20/2006
Citation: Shelly, T., Mcinnis, D.O., Rendon, P. 2006. The sterile insect technique and the mediterranean fruit fly: assessing the utility of aromatherapy in large field enclosures. Entomologia Experimentalis et Applicata. 116:199-208

Interpretive Summary: The sterile insect technique (SIT) is widely used in programs against tephritid fruit flies, particularly the Mediterranean fruit fly. Unfortunately, the mass-rearing procedures inherent to the SIT often lead to a reduction in male mating competitiveness. One solution for this problem is to provide a mating stimulant to males prior to release. One such compound for sterile medfly males is ginger root oil that is known to significantly increase male mating effectiveness versus wild males for matings with wild females. In this study we have examined this effect at a higher scale involving flies released into large field cages in both Guatemala and Hawaii. Males exposed to ginger root oil were significantly better at inducing desired egg sterility in wild females in Hawaii and also yielded a further 25% reduction in progeny production over non-exposed males in the Guatemala studies.

Technical Abstract: The sterile insect technique (SIT) is widely used in integrated programs against tephritid fruit flies, particularly the Mediterranean fruit fly, Ceratitis capitata Wiedemann (Diptera: Tephritidae). Unfortunately, the mass-rearing procedures inherent to the SIT often lead to a reduction in the male mating competitiveness. One potential solution involves the prerelease exposure of males to particular attractants. In particular, male exposure to ginger root oil [Zingiber officinale Roscoe (Zingiberaceae); hereafter GRO], has been shown to increase mating success dramatically in field cage trials. To evaluate more rigorously the effectiveness of GRO exposure, we here describe two projects that compared levels of egg sterility or pupal yield, respectively, following the release of wild flies and either GROexposed (treated) sterile males or GRO-deprived (control) sterile males in large field enclosures. In both projects, sterile males from a genetic sexing strain were exposed as adults to GRO for 24 h while held in large storage boxes. In Hawaii, we dissected eggs from fruits to determine the percentage of egg hatch at four overflooding ratios, ranging from 5 : 1 to 60 : 1 (sterile : wild males), and found that, at all four ratios, the proportion of unhatched (sterile) eggs was significantly greater in enclosures containing GRO-exposed males than control males. In Guatemala, we allowed larvae to develop in fruits and counted the number of pupae produced. At the only overflooding ratio tested (25: 1), pupal yield was approximately 25% lower for enclosures containing GRO-exposed males than control males, although this difference was not statistically significant. An explanation for the differing outcomes is proposed, and the implications of these findings for the SIT are discussed.