Submitted to: Journal of Economic Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/5/2006
Publication Date: 12/1/2006
Citation: Yokoyama, V.Y., Miller, G.T., Stewart-Leslie, J., Rice, R.E., Phillips, P.A. 2006. Olive fruit fly (diptera: tephritidae) popultations in relation to region, trap type, season, and availability of fruit. Journal of Economic Entomology. 99(6):2072-2079.
Interpretive Summary: Olive fruit fly has been a serious economic threat to the California olive industry since its discovery in 1998. High populations of the pest are found in olives in the coastal areas of California, while low numbers exist in the San Joaquin Valley of California where most of the domestic canned olives in the U.S. are produced. Improved methods are needed to detect, monitor, and control olive fruit fly in the production areas. A novel attract-and-kill trap was investigated as a control device, and two types of traps were studied for attractiveness to olive fruit fly adults. The attract-and-kill trap did not greatly reduce the pest populations in an isolated area, but a simple yellow panel trap was found to be excellent for detecting the pest in an orchard. Other findings showed that olives are susceptible to attack in the very early stages of development, and that all fruit should be harvested in orchards to prevent reoccurring pest populations. The findings support the development of cultural control methods for the pest that can devastate the $68 million olive crop in California.
Technical Abstract: The number of olive fruit fly, Bactrocera oleae (Gmelin), adults (mean ± SEM) captured per day in ChamP traps placed in olive, Olea europaea, trees in an isolated test site (2001 Grapevine, CA) was lower among trees with attract-and-kill traps (1.4 ± 0.7) but not significantly different (P = 0.34) from trees without attract-and-kill traps (1.6 ± 0.9). Mean percentage of captured females in Pherocon ® AM traps versus ChamP traps was not significantly different in spring or summer in a commercial orchard (2002 Arroyo Grande, CA). The seasonal mean ± SEM total number of olive fruit fly adults captured per day in Pherocon ® AM traps (2.0 ± 0.2 in summer to 16.0 ± 3.1 in spring) was significantly higher (P < 0.01) than in ChamP traps (0.8 ± 0.1 in summer to 11.8 ± 2.6 in spring) for the sum of all collection dates. The mean olive fruit fly adults collected per useable area of Pherocon ® AM trap (389.1 ± 2.5 cm²) and Champ trap (440.1 ± 8.2 cm²) was 0.32 and 0.21 adults per cm² respectively, for 7-12 d spring collections and 0.07 and 0.02 adults per cm² respectively, for 14 d summer collections. Ovipositional sites (punctures or stings) were found on small olive fruit (< 1 cm³) during the summer and multiple ovipositional sites (> 2) occurred on larger fruit (> 1 cm³) during the fall when olive fruit fly populations were high (2002 Grapevine, CA). Non-harvested fruit that remained in trees since the October harvest of the previous year supported low numbers of olive fruit fly from March through May (0.4-6.4 pupae per 10 g olives), which included the bloom period (2001-2002 Arroyo Grande, CA).