California Agriculture Online
California Agriculture Home  >   Volume 57   >   Number 4  >   Viewing Expanded Abstract

Peer-reviewed Article

Olive fruit fly populations measured in Central and Southern California


Richard Rice, UC Davis
Phil P. Phillips, UC Cooperative Extension (UCCE)
Judy Stewart-Leslie, Pest Management Associates, Exeter
G. Steven Sibbett, UCCE Tulare

publication information

California Agriculture 57(4):122-127. DOI: 10.3733/ca.v057n04p122. October-December 2003.


The olive fruit fly was detected in Southern California in October 1998. This nonnative pest, which can render fruit unmarketable, has since moved throughout California and is now believed to be present wherever olives are grown in the state. Seasonlong trapping of adult flies in the San Joaquin Valley, and Ventura and Santa Barbara counties in 2001 and 2002 showed similarities in seasonal phenology, but also differences primarily due to varying temperatures and fruit availability. In the San Joaquin Valley, fly activity declined as maximum daily temperatures rose above 90°F, but increased when temperatures were between 70°F and 85°F. On the Southern California coast, the combination of available, susceptible fruit and moderate climate throughout the year may allow continuous reproduction of OLF with six or perhaps even seven generations per year.

author affiliations

R.E. Rice is Entomologist Emeritus, Department of Entomology, UC Davis and Kearney Agricultural Center, Parlier; P.A. Phillips is Central Coast IPM Advisor, UC Cooperative Extension (UCCE), Ventura; J. Stewart-Leslie is Pest Control Advisor, Pest Management Associates, Exeter; G.S. Sibbett is Farm Advisor Emeritus, UCCE Tulare. The cooperation and free exchange of information from European colleagues and researchers has been invaluable to California olive growers in formulating a response to the olive fruit fly. In particular, we thank G.E. Haniotakis, O.T. Jones, A.P. Economopoulos and A. Montiel-Bueno. We also thank E. Fisher, California Department of Food and Agriculture (CDFA), for determinations of the mating status of female flies; CDFA for financial support and trapping supplies; Janet Nelson and the California Olive Committee for encouragement and financial support; and the many growers who provided access to their groves for these studies.


[CDFA] California Department of Food and Agriculture. 2002. Sacramento, CA:California Agricultural Resource Directory. 176.

Economopoulos AP. The olive fruit fly, Bactrocera (Dacus) oleae (Gmelin) (Diptera: Tephritidae): Its importance and control; previous SIT research and pilot testing. 2002. Report to International Atomic Energy Agency (IAEA), Vienna, Austria. 44 p.

Economopoulos AP, Haniotakis GE, Michelakis S, et al. Population studies on the olive fruit fly, Dacus oleae (Gmel.) (Dipt., Tephritidae) in Western Crete. Z Ang Ent. 1982. 93:76.

Fletcher BS, Pappas S, Kapatos E. Changes in the ovaries of olive flies, Dacus oleae (Gmel.) during the summer, and their relationship to temperature, humidity and fruit availability. Ecol Entomol. 1978. 3:107.

Haniotakis G. Effect of size, color and height of sticky traps on captures of Dacus oleae. Entomologia Hellenica. 1986. 4:61.

Kapatos ET, Fletcher BS. The phenology of the olive fly, Dacus oleae (Gmel.) (Diptera, Tephritidae), in Corfu. Z Ang Ent. 1984. 98:70.

Longo S, Benfatto D. Observation on olive fly (Dacus oleae (Gmel.)) — Population dynamics in Sicily. Proc CEC/IOBC Int Symp, Fruit Flies of Econ Importance 1982. Athens, Greece. Rotterdam:AA Balkema. 612p. 615.

McFadden MW, Kapatos E, Pappas S, Carvounis G. Ecological studies on the olive fly Dacus oleae (Gmel.) in Corfu. I. The yearly life cycle. Estr dal Boll del Lab Entomol Agraria “Filippo Silvestri” di Portici. 1977. 34:50.

Michelakis S. Bio-ecological data of the olive fly (Dacus oleae (Gmel.)) in Crete-Greece. In: Proc Second Int Symp on Fruit Flies 1986. Crete, Greece. Amsterdam:Elsevier Science. 397p. 405.

Michelakis SE. The olive fly (Dacus oleae (Gmel.)) in Crete, Greece. Acta Horticulturae. 1990. 286:4.

Montiel-Bueno A. The use of sex pheromone for monitoring and control of olive fruit fly. In: Proc Second Int Symp Fruit Flies 1986. Crete, Greece. Amsterdam:Elsevier Science. 483p. 895.

Moore I. Further investigations of the artificial breeding of the olive fly Dacus oleae (Gmel.) under aseptic conditions. Entomophaga. 1962. VII:57. DOI: 10.1007/BF02375992 [CrossRef]

Phillips PA, Rice RE. Olive fly trapping surveys in Southern California. UC Plant Prot Quar. 2001. 11(1):3. .

Ramos P, Jones OT, Howse PE. The present status of the olive fruit fly (Dacus oleae (Gmel.)) in Granada, Spain, and techniques for monitoring its populations. In: Proc CEC/IOBC Int Symposium, Fruit Flies of Economic Importance 1982. Athens, Greece. Rotterdam:AA Balkema. 38p. 40.

Rice RE. Bionomics of the olive fruit fly, Bactrocera (Dacus) oleae.. UC Plant Prot Quar. 2000. 10(3):5. .

Todd FE. The olive fly (Dacus oleae Rossi). Mo Bull Calif Dept Agric. 1929. 18(10):33.

Tzanakakis ME. Summer diapause in the olive fruit fly and its significance. In: Proc Second Int Symp Fruit Flies 1986. Crete, Greece. Amsterdam:Elsevier Science. 383p. 386.

Tzanakakis ME, Koveos DS. Inhibition of ovarian maturation in the olive fruit fly, Dacus oleae (Diptera: Tephritidae) under long photophase and an increase of temperature. Ann Entomol SocAmer. 1986. 79:18.