Submitted to: Subtropical Plant Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/5/2006
Publication Date: 12/4/2006
Citation: Fraser, I., Robacker, D.C. 2006. Attraction of naive and fruit-experienced Mexican fruit flies (Diptera: Tephritidae) to mangoes and grapefruits in wind-tunnel bioassays. Subtropical Plant Science. 58:12-17. Interpretive Summary: Mangoes and citrus are among the favorite hosts of the Mexican fruit fly, a pest of fruit that inhabits Mexico and south Texas and occasionally invades California and other citrus-producing areas of the United States. In fact, the threat of invasion by this pest makes it a target of agricultural agencies all over the tropical and subtropical regions of the world. Reasons are that infested fruit loses much of its market value and more importantly, cannot be exported to other countries that fear establishment of this insect in their citrus- or mango-producing areas. Studies of how the Mexican fruit fly chooses its hosts are needed to increase understanding of its biology, clearing the way to more effective control and eradication programs. In this work, we studied whether female flies are attracted instinctively to mangoes and if they prefer mangoes to grapefruits for oviposition. Results showed that flies were not instinctively attracted to mangoes or grapefruit, but learned to be attracted to both fruits if they had experience with either while they were young. Also, flies greatly preferred grapefruits to mangoes for laying eggs. These results indicate that infestations of this fly should be higher in grapefruit than in mango orchards if both occur in the same geographical region. Also, results suggest that removing fruit from orchards during the off-season may reduce future infestations by preventing young, inexperienced flies from learning these fruits are hosts. These studies show that simple cultural practices could have major impacts on infestations of mangoes and citrus by fruit flies.
Technical Abstract: Wild strain, mated, female Mexican fruit flies, Anastrepha ludens (Loew), with no prior experience with fruit (naive), were attracted to grapefruits (Citrus paradise), but not to mangoes (Mangifera indica) in wind tunnel experiments. However, attraction to grapefruits was not strong. Oviposition experience with either grapefruits or mangoes prior to testing, increased attraction to both fruits. Experience with grapefruits increased attraction to grapefruits more so than to mangoes and experience with mangoes increased attraction to mangoes more so than to grapefruits. Oviposition propensity was greater on grapefruits than on mangoes and was not affected by fruit experience. Oviposition propensity on mangoes was not greater than on plastic yellow balls. Responses of laboratory females were similar to those of wild females, except that responses were generally higher and naive females were attracted to mangoes as well as grapefruits. Wild strain, sexually mature, naive males were attracted to grapefruits, but not mangoes and fruit experience had little effect. Laboratory males were attracted to both fruit types, and experience with either fruit type increased attraction to mangoes. These results indicate that Mexican fruit flies are not strongly attracted to grapefruits or mangoes, unless they have previous experience with them and demonstrate that mangoes stimulate only a weak oviposition response compared with grapefruits.