Submitted to: Journal of Environmental Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: September 27, 2002
Publication Date: January 1, 2003
Citation: Mcquate, G.T., Jones, G.D., Sylva, C.D. 2003. Assessment of corn pollen as food source for two tephritid fruit fly species. Journal of Environmental Entomology. 32:141-150. Interpretive Summary: The melon fly is a serious pest of cucurbit crops (cucumbers, squash, melons, etc.) in many Asian countries, several African countries, and several Pacific islands including Guam and the Hawaiian islands. Melon flies are known to be associated with a range of non-host plants, including corn and castor bean. This association has been used for control purposes by spraying protein baits incorporating a toxicant on these non-host plants. The attraction of melon flies to corn plants has not been reported to vary with corn developmental stage. We report field studies that show that melon flies and, to a lesser extent, oriental fruit flies, may show increased population levels in corn at the time of, and subsequent to, flowering and pollen shed. We suggest that these population increases may be tied to pollen consumption. Pollen has not been reported to be an important food source for tropical tephritid fruit flies. For control programs, it is important to recognize that both melon fly and oriental fruit fly populations may increase in corn during, and subsequent to, pollen shed. This attraction to pollen could also be utilized for control purposes through the development of a dipteran specific Bt corn, though research on the potential impact on nontarget species would be needed.
Technical Abstract: The melon fly, Bactrocera cucurbitae (Coquillett) is a serious pest of cucurbit crops. Although melon fly females oviposit in cucurbit crops, both males and females are frequently associated with a range of non-host plants, including both crops such as corn (Zea mays C. Linnaeus) and wild plants such as castor bean (Ricinus communis C. Linnaeus) that occur within the cropping area or along the crop borders. This association with non-host plants has been used for control purposes through the technique of spraying protein baits incorporating a toxicant on these non-host plants. Association of melon flies to corn has not been reported to be tied to any phonological stage of corn. We report field studies that show that melon flies, as well as oriental fruit flies, B. dorsalis (Hendel), may show increased population levels in corn at the time of, and subsequent to, flowering and pollen shed and suggest that this population increase may be tied to pollen consumption. Prior to this, pollen had not been reported to be an important food source for the tropical Bactrocera spp.