To Smell or to Taste: Application of ginger root oil and methyl eugenol to boost sterile male performance in SIT programs

Authors: McInnis, Donald; SHELLY, TODD - USDA APHIS

Submitted to: Fruit Flies of Economic Importance International Symposium
Publication Type: Abstract Only
Publication Acceptance Date: 6/30/2006
Publication Date: 9/30/2006
Citation: Mcinnis, D.O., Shelly, T. 2006. To Smell or to Taste: Application of ginger root oil and methyl eugenol to boost sterile male performance in SIT programs. Fruit Flies of Economic Importance International Symposium.

Interpretive Summary: The use of aromas to affect the behavior of tephritid fruit flies has its origin in the use of certain male attractants, or parapheromones, such as methyl eugenol or a-copaene. Natural sources, including plant flowers or stems, have been found to emit such compounds and can benefit males of certain fly species. Artificial sources of these same compounds can be used to improve the quality of male flies exposed to them. Laboratory mating improvements to a Hawaii lab strain of OFF were realized several years ago. Recently, field demonstrations of laboratory-based initial studies of the chemotherapeutic effects of ginger root oil (GRO) on medflies and methyl eugenol (ME) on the OFF have been carried out in Hawaii, and later in California, Florida, Guatemala, and several other foreign countries. The application of GRO has progressed rapidly in scope beginning with exposures in small cups, to large holding boxes, to large rooms holding millions of sterile male adults in operational programs. Similarly, the testing area for evaluating the mating and survival abilities of GRO treated males compared to control males has progressed from small lab cages, to standard outdoor field cages, to much larger field cages, and finally, to the open field where millions of sterile males were released. In all of these cases, exposures of 12 –24 hrs of GRO to young male medflies has resulted in at least a doubling of mating ability against wild or wildish females at a very low cost.

Technical Abstract: Chemical aromas emitted by plants, insects, or other animals have long been known to affect the behavior of insects. Strictly speaking, the use of aromas to improve the condition of an animal (or plant) is known as aromatherapy, while in general terms, chemotherapy involves the similar use of any type of chemical, whether it be aromatic or not. Natural sources, including plant flowers or stems, have been found to emit such compounds and can benefit males of certain fly species. Artificial sources of these same compounds can be used to improve the quality of male flies exposed to them. Ginger root oil has been shown to strongly improve the mating of sterile males of the Mediterranean fruit fly so that they can compete better with wild males for matings with wild females in sterile insect release programs. This fact improves the efficiency of sterile fly programs. Similarly, the compound, methyl eugenol, a known powerful male attractant used in trapping programs, has been shown to stimulate males of the oriental fruit fly in mating. So, using this compound can increase the mating advantage of sterile males exposed to the compound. One big difference between chemotherapy with ginger root oil and methyl eugenol is that the former only requires the strong aroma to effect a change in the males (ca. 3 mls per million males exposed), while for methyl eugenol, the males need to feed on the compound in order to get the mating advantage. In both cases, the chemical stimulant can boost the mating ability of sterile males by 2-3 fold under field conditions.