Submitted to: Meeting Abstract
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: December 1, 2004
Publication Date: May 10, 2002
Citation: Yokoyama, V.Y., Miller, G.T., Sivinski, J.M. 2002. Quarantine control strategies for olive fruit fly in california. Proceedings of the 6th International Fruit Fly Symposium, May 6-10, 2002, Stellenbosch, South Africa. p.241-244. Interpretive Summary: The recent establishment of olive fruit fly, Bactrocera oleae, in California has threatened to destroy the U.S. olive industry. Methods are needed to control the new pest and prevent economic losses in olives used for canning and oil production. Immersion of the fruit in brine solutions was found to prevent the immature stages of the pest from emerging from fruit and was developed as a method to prevent spreading the infestation when harvested fruit is transported to distant processing plants. Low temperature storage of harvested olives at 36-37 F after three weeks caused death of the immature pest stages in the fruit and was proposed for use as a control method after harvest. Differences were found in susceptibility of olive varieties to attack by olive fruit fly, which suggests the need to monitor susceptible orchards for potential pest attack. Attract and kill traps consisting of baits and lures attached to paper impregnated with an insecticide were tested, but did not greatly reduce olive fruit fly numbers in infested trees. Biological control using a tiny imported wasp that attacks the immature stages of olive fruit fly in the fruit was found to reduce the survival of olive fruit fly adults that emerged from the exposed fruit. Research findings for containment tactics, control during storage of the fruit, fruit susceptibility to attack, control traps, and biological control were developed as recommendations and submitted to the olive industry for immediate implementation.
Technical Abstract: Immersion of infested fruit in 1% acetic acid brine solution prevented olive fruit fly larval emergence from the beginning of exposure through 5 d. A mean ± SEM of 66.8 ± 7.8 larvae emerged from infested olives in the controls during the 5 d test. Low temperature storage for 2 weeks at 0-1C and 3 weeks at 2-3C attained >99% control of the immature stages of olive fruit fly in infested fruit. Comparison of the Mission versus the Manzanillo olive cultivars in laboratory choice tests after 2-3 d exposure to olive fruit fly adults, showed that 68% of the third instars, pupae, and adults reared from both cultivars were reared from Manzanillo fruit. Fruit of both cultivars were attacked in all stages of maturity and 56% of the ovipositional sites and 69% of the insects were collected from fruit in the green versus red blush stage. The number of adult olive fruit fly adults captured in Champ traps used for monitoring populations was slightly lower in trees with Eco-Traps than in control trees without Eco-Traps. The mean ± SEM number of adults collected per trap on the eight trap dates in the control and Eco-Trap treated trees was 39.5 ± 22.8 and 33.0 ± 17.1, respectively, and was not significantly different. Percentage parasitism based on the calculated total number of 2nd instar olive fruit fly larvae and number of parasitoids reared from the exposed infested fruit, increased in laboratory cage tests with an increase in exposure from 2 to 4 days. Parasitism was highest in field cage tests and only 4.5% less in infested fruit in the vicinity of the field cages.