Submitted to: Fruit Flies of Economic Importance International Symposium
Publication Type: Abstract only
Publication Acceptance Date: 1/10/2014
Publication Date: 4/24/2014
Citation: Yokoyama, V.Y. 2014. Biology, behavior, and olive orchard IPM of Bactrocera oleae (Rossi) fifteen years after invasion in California. Abstracts of the 9th International Symposium on Fruit Flies of Economic Importance, May 12-16, 2014, Bangkok, Thailand. p. 114. Interpretive Summary:
Technical Abstract: Background: Olive fruit fly, Bactrocera oleae L., has become a key pest in California commercial olive orchards used for canned fruit and oil since it was first discovered in 1998. Elucidation of the biology and behavior of olive fruit fly in relation to its host has been a key factor in development of new control techniques. Implementation of a systems approach to olive fruit fly management incorporating a number of control tactics was investigated for reducing infestations in olives. Methods: Rearing olive fruit fly life stages to conduct laboratory, greenhouse, and field tests was accomplished by collecting infested olives from the coastal areas of California. Emerging larvae were collected as pupae, placed in cages until adult emergence, provided non-infested olives for oviposition, and the fruit held to produce specific life stages for incubator and greenhouse tests. The response of life stages to temperature, humidity, and mobility in test arenas was determined through various replicated tests in different simulated environments. A parasitoid, Psyttalia humilis was imported from Guatemala and studied in laboratory tests or released to determine rates of parasitism in different regions of California. Trapping techniques for monitoring and a novel attract-and-kill trap created from corrugated plastic were evaluated for attractiveness to olive fruit fly adults. Results: Olive fruit fly adults survived with food and water in incubators for 63 days at constant 15°C and 59% RH; and 4 d with and 2 d without provisions at 35°C and 29% RH. In the greenhouse, survival was 203 d at 26°C and 63% RH daytime and 8-11 d at 36°C and 31% RH daytime. In the field, the greatest number of adults monitored with yellow sticky traps with baits and lures was collected in fall, and highest number of pupae was collected from non-harvested fruit in the spring (mean 6.4 per 10 g fruit). One adult could be reared per fruit that was greater than or equal to 1 cm long in cage tests. Olive fruit fly larvae had three instars based on length, and the third instar was capable of travelling for 6.9 h over 23.9 m. Biological control attained as high as 100% control under ideal coastal conditions, but lacked permanency. Conclusions: Olive fruit fly can be reduced to low numbers in the hot and arid California Central Valley where the pest is susceptible to high temperatures. Systems approaches for pest suppression include early harvest, removal of unpicked fruit, elimination of standing water in orchards, precise use of bait sprays possibly with attract-and-kill traps, and active monitoring programs to determine abundance and dispersal. Biological control may be practical in coastal regions when infested fruit may be present throughout the year. Key practices can reduce the pest to non-economically important levels that can be tolerated by the canned fruit and olive oil industries.