The Invasive Species, Bactocera olea

1
University of California Agriculture and Natural
Resources COOPERATIVE EXTENSION
Local Response to
The Invasive Species, Bactocera olea
William H. Krueger, UCCE, Glenn County
Table olives are currently produced on 12,000
acres in Glenn and Tehama Counties. This
industry has a total value to the local economy
of 175 million dollars. In 1998, the Olive
Fruit Fly (OLF) (figure 1) was trapped in the Los
Angeles area. It spread rapidly and can now be
found virtually anywhere olives are grown in
California. OLF lays eggs in the olive fruit
(figure 2) that hatch into maggots that feed and
tunnel through the fruit (figure 3). Damaged
fruit are susceptible to attack by secondary
decay organisms (figure 4). Damage is mostly
internal and difficult to remove in the packing
shed. The potential consequences of infested
fruit on marketing mandates a very low tolerance.
As the OLF population continues to develop, it
remains to be seen if olive growers will be able
to meet these requirements. The survival of this
industry is dependent upon developing and
adopting effective and economical control
methods. Research funded by California Olive
Committee (COC), University of California, USDA
and CDFA is currently underway to find efficient
and economical methods for controlling OLF under
California conditions. UC Cooperative Extension
in Glenn and Tehama Counties is conducting
research and educational programs to provide
growers with the most effective and economical
tools. This effort is a good example of how UCCE
can function collaboratively with other agencies,
individuals and private industry to bring the
resources of the University to bear on locally
important issues. Our activities can be divided
into outreach and research and are described
below.
Figure 1. Adult Female Fly
Outreach The Sacramento Valley Olive Day was
held in Tehama County in 2004 and Glenn County in
2005 with a primary focus on OLF. Researchers
presented results to growers. Each meeting had an
attendance of approximately 200 and was supported
by local processors. Media Day (figure 5) was
organized and presented to local media to
encourage the removal of non- commercial olive
trees to minimize the risk to commercial
orchards. Newsletters with up to date
information on OLF were produced 4 times annually
and sent to a mailing list of approximately 330
growers and industry personnel.
Flyers Controlling Olive Fruit Fly in
Non-Commercial Orchards (figure 6) provides
information on OLF for homeowners and caretakers
of ornamental olive trees. This is important
because of the threat that uncontrolled
populations in these trees pose to commercial
orchards. The publication was distributed at the
2005 Olive Day, has been given out at our office
and is posted on our website. Additionally, 700
copies were mailed to non-commercial olive
growers by the Glenn County Olive Pest Control
District. Controlling Olive Fruit Fly In
Commercial Orchards (figure 7) presents the
latest information on controlling OLF for
commercial growers. It was printed in English
and Spanish on the same publication because of a
significant Hispanic population among olive
growers. It was mailed to all of the olive
growers in Glenn, Tehama and Butte Counties and
is posted on our website. To date 1300 copies
have been printed. It will be updated and
redistributed in 2006.
Figure 2. Ovipositional Stings in Fruit
Figure 3. Small Larvae and Feeding Traces
Figure 4. Olive Fly Larvae in Decaying Fruit
Research Coordination of USDA researchers
specializing in sorting of agricultural products
resulted in COC funding for investigating methods
of mechanically sorting infested fruit.
Potentially this could increase the tolerance for
infested fruit and make IPM programs more
feasible. Collaborative research with UC
Entomologist Frank Zalom and UC graduate student
Hannah Burrack is underway in Glenn County and
has been supported by a COC grant which has
provided 5000 annually for two years. In
2004, research demonstrated superior performance
for the plastic McPhail trap (figure 8) for
monitoring OLF populations in local orchards
compared to the standard yellow sticky trap.
Local pesticide dealers were encouraged to make
these traps available. As a result, many growers
have switched to this type of trap.
During 2005 alternative control measures
including the standard GF 120 Spinosad spray,
homemade OLIPE bottle traps (figure 9) for mass
trapping, attract and kill traps (figure 10) and
Surround spray (figure 11) for repelling OLF are
being compared in a replicated trial.
Olive Fly information and links posted on the
Glenn County CE website include updated trap
results, the publications described above, UC IPM
Pest Management Guidelines, 2005 UC
Recommendations For Controlling Olive Fly,
sources of OLF trapping materials, instructions
for OLIPE traps, UC Backyard Orchard publication
on OLF and other links with useful information.
Work with local Agricultural Commissioners
resulted in GF 120 (the only pesticide currently
available for commercial growers) being available
for non commercial trees.
Figure 8. McPhail Trap
Figure 9. OLIPE Trap
Figure 10. Attract and Kill Trap
Figure 5. Media Day Chico Enterprise Record
article
Technical advice was provided for Glenn and
Tehama Counties Olive Pest Control
Districts. The outreach program described above
is being partially funded by a CDFA grant of
approximately 7500 annually for three years
administered through the Tehama County
Agricultural Commissioners office.
Conclusion The table olive industry in
California is at risk. Work being done locally
by CE is serving to catalyze efforts underway by
individuals, agencies and private industry to
combat this invasive species and make the results
of this work accessible to the growers. These
activities are critical to the continued survival
of the table olive industry in California.
Figure 6. Ornamental Tree Brochure
Figure 11. Surround Spray
Figure 7. Commercial Orchard Brochure
Contact Bill Krueger, UCCE Glenn County (530)
865-1107 - whkrueger_at_ucdavis.edu
Website http//ceglenn.ucdavis.edu