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UNIVERSITY OF CALIFORNIA COOPERATIVE EXTENSION TREE TOPICS INFORMATION FOR TREE FRUIT AND NUT GROWERS IN CALIFORNIA’S CENTRAL COAST REGION JULY 21, 2009 VOLUME 34, ISSUE 4_

IN THIS ISSUE:

 SPOTTED WING DROSOPHILA MEETING  SPOTTED WING DROSOPHILA  LIGHT BROWN APPLE MOTH  WALNUT HUSK FLY  SECOND FLIGHT CODLING MOTH ______

SPOTTED WING DROSOPHILA MEETING

There will be a meeting on the spotted wing drosophila (Drosophila suzukii) on Thursday, July 30 from 9:30 a.m. until 12 noon at the San Martin Lions Club at 12415 Murphy Avenue in San Martin. Please see the attached agenda for more details. This meeting is sponsored by the University of California Cooperative Extension and the Agricultural Commissioners from Santa Clara, San Benito, Santa Cruz and Monterey Counties.

SPOTTED WING DROSOPHILA

Spotted wing drosophila (SWD) is the new name for the fly that caused extensive damage to sweet cherry fruits this year in Santa Clara County as well as many other counties. It was previously called cherry vinegar fly or cherry drosophila. Here is a summary of what we know:

Scientific Name: Drosophila suzukii

Host range: Confirmed – cherry, strawberry, raspberry, blackberry, blueberry. Suspected – grape, other stone fruits. Adults: Small flies (2-3 mm) with red eyes, a pale brown thorax and black stripes on the abdomen. The adult male flies have a black spot at the end of the wings. The ovipositor of female SWD is large and serrated.

Larva: The larva of the SWD is a small white maggot. The number of maggots that are present in each fruit may vary from one to several.

Damage: The first indication of damage is a “sting” or depressed area where the ovipositor has punctured the fruit. Eggs are laid underneath that rapidly hatch into larvae that begin feeding. The flesh becomes soft, often with a drop of fluid exuding from the puncture hole. Secondary rots may cause flesh browning.

Life Cycle: Generation time varies with temperature but may range from one to several weeks. As many as three generations may occur just during cherry harvest and 10 to 15 or more may occur through the year. In Japan, adult flies can be found throughout much of the year.

Trapping: A number of trap types have been successfully utilized but we are still researching this monitoring tool. I am currently using liquid traps containing apple cider vinegar. These traps do catch other species of Drosophila.

Control: Control measures are still being developed. Low to moderate populations appear to be successfully controlled by the insecticide bait material GF-120 which has a zero day pre-harvest interval and is organically acceptable. For larger populations, we will be looking at other insecticides mixed with bait materials similar to what is utilized for walnut husk fly and many other tephritid fruit flies.

Management: Make sure everyone in your vicinity applies control measures. In cherry orchards, watch early ripening varieties such as Black Tartarian and Early Burlat for the first signs of infestation. Destroy or remove from the orchard all infested fruit.

LIGHT BROWN APPLE MOTH

From the San Benito Agricultural Commissioner:

The discovery of several Light Brown Apple Moths in northern San Benito County has led to two quarantine areas being established in the Aromas area and in the Hollister area. The Light Brown Apple Moth (LBAM) is a destructive pest that is native to Australia and was first found in California in 2007. More than two-thousand plant species are known to be susceptible to attack by this pest including, broccoli, lettuce, cherries, apricots, walnuts, tomatoes and peppers. To help prevent the spread of LBAM, quarantine zones are established when two or more moths are found within the same area. Within the quarantine area, the movement of plants and plant products is restricted. All movement of products can only be done under the conditions that are specified by the quarantine. All agricultural and nursery producers must have a Compliance Agreement issued by the US Department of Agriculture. The Compliance Agreement will specify the conditions for movement of commodities. Producers need to meet with a USDA representative to obtain a Compliance Agreement for their operation. USDA representatives will come directly to the individual farms and meet with the grower to develop the Compliance Agreement. To see if your field is in the quarantine area, click on the respective maps. If you should have any questions or wish to schedule an appointment with a UDSA representative, please call our office at (831) 637-5344. Aromas area LBAM quarantine map http://www.san- benito.ca.us/departments/ag/documents/AromasLBAMQuarantineArea6-23-09.pdf

Hollister area LBAM quarantine map http://www.san- benito.ca.us/departments/ag/documents/HollisterLBAMQuarantineArea6-23-09.pdf

July 19, 2009 Update: A Light Brown Apple Moth was recently found on Frye Lane, south of Shore Road. This will mean that the existing Hollister quarantine zone in this area will most likely be extended west from its current boundary. At this time, the new boundary has not been established, but the northwest corner of the existing quarantine zone may move west to approximately Frasier Lake Road. This is not official yet, and the exact course of action has not yet been determined. Note: For general information on LBAM and for quarantine maps for other counties go to the statewide LBAM web site which is located at: http://www.cdfa.ca.gov/phpps/PDEP/lbam/lbam_main.html.

WALNUT HUSK FLY

The first walnut husk flies (WHF) of the season were caught in the Southside area of San Benito County in early June. This is usually the earliest location in the Central Coast for WHF emergence. WHF populations are currently very high in a number of orchards from Hollister to Tres Pinos. Be sure to monitor for WHF with the yellow sticky AM traps with ammonium carbonate superchargers. Replace the sticky trap weekly if you have high populations or a dusty situation. Replace the ammonium carbonate if it disappears (volatilizes) or gets wet. Shake the container up weekly to break up any surface layer.

WHF control is accomplished with the use of bait sprays such as GF-120 (low to moderate populations only), Entrust plus molasses or malathion plus Nu-Lure. Both GF-120 and Entrust can be used in organic orchards. See our UC IPM Pest Management Guidelines for a more complete list of control measures at the web site http://www.ipm.ucdavis.edu/PMG/r881301211.html.

Do not rely on full coverage sprays for codling moth control to provide WHF control. These sprays may provide some temporary suppression. Bait sprays for WHF are usually applied at low volumes with large droplet size with a hand gun sprayer or a converted weed sprayer (with a clean tank!).

SECOND FLIGHT CODLING MOTH

These are estimated dates for the second flight of codling moths in apples and walnuts in the Central Coast. I have re-adjusted my second flight biofix to about 1100 DD to better fit trap data. If you are past these dates and need to spray – go ahead. Confirm the need to spray with trap counts and first flight damage. Data from the Morgan Hill weather station is unavailable (use Ausaymas) and the Freedom weather station has incomplete information (estimates are listed below). The spray date for a particular orchard may vary widely from the norm due to microclimates and population size and so must be confirmed with your own trap and damage data.

Hollister Ausaymas Freedom Santa Cruz Beginning of flight July 6 June 29 mid-July July 25 250 DD spray date July 19 July 14 early August August 12

Spotted-WingSpotted-Wing DrosophilaDrosophila Drosophila suzukii (Formerly known as Cherry Vinegar Fly) Thursday,Thursday, JulyJuly 30,30, 20092009 9:009:00 amam -- 12:0012:00 San Martin Lions Club 12415 Murphy Avenue San Martin

This meeting is intended to update producers of cherries, cane berries and other fruits on the impact of this new pest.

SPEAKERS Representatives from the California Department of Food and Agriculture and the University of California will discuss biology, distribution, known and potential hosts, possible implications for export markets, and control strategies.

Growers, Pest Control Advisors, Industry Members and others interested in learning about this new pest are encouraged to attend.

Please call the Santa Clara County Division of Agriculture to reserve your seat. (408) 465-2900

2 Units of Continuing Education for Certified Private Applicators, QAL, QAC, and PCA Licensees (2 hrs. of “Other”). Sponsored by: Monterey County Agricultural Commissioner San Benito County Agricultural Commissioner Santa Clara County Agricultural Commissioner Santa Cruz County Agricultural Commissioner UC Cooperative Extension

Agenda 9:00 a.m. Coffee and Registration

9:30 - 9:45 Welcome and Introduction Greg Van Wassenhove, Santa Clara County Agricultural Commissioner

9:45 – 10:05 Distribution, Biology, Known and Potential Hosts Kevin Hoffman, California Department of Food and Agriculture

10:05 - 10:20 Potential Quarantine Ramifications Nick Condos, California Department of Food and Agriculture

10:20 – 10:35 BREAK -- Thank you to Crop Protection Services in Hollister for supplying the food and beverages!

10:35 - 11:00 Experiences and Control in Coastal Berry Crops Mark Bolda, Farm Advisor, Strawberries and Caneberries, Santa Cruz, Monterey and San Benito Counties

11:00 – 11:30 Central Coast Cherry Experiences and Trap Comparison Bill Coates, Farm Advisor, Tree Fruits and Nuts, San Benito, Santa Cruz, Santa Clara and Monterey Counties

11:30 – 12:00 Spotted-Wing Drosophila Biology Dr. Robert Van Steenwyk, Entomologist, Department of Environmental Science, Policy and Management, UC Berkeley William (Bill) W. Coates Acting County Director Univ. of Calif. Cooperative Extension Farm Advisor, Fruit and Nut Crops 649 San Benito Street, Suite 115 San Benito, Santa Cruz, Santa Clara Hollister, CA 95023 and Monterey Counties (DO NOT USE ABOVE ADDRESS FOR MAIL) (831)637-5346 phone Mail: P.O. Box 1956 (831)637-7111 FAX Hollister, CA 95024-1956 e-mail: [email protected] web: http://cesanbenito.ucdavis.edu/

For those without Internet access, call or write to me and I will provide hard copies of any information mentioned above. Reference to commercial products or trade names is with the understanding that no discrimination is intended, and no endorsement by Cooperative Extension is implied. The University of California prohibits discrimination or harassment of any person on the basis of race, color, national origin, religion, sex, gender identity, pregnancy (including childbirth, and medical conditions related to pregnancy or childbirth), physical or mental disability, medical condition (cancer-related or genetic characteristics), ancestry, marital status, age, sexual orientation, citizenship, or status as a covered veteran (covered veterans are special disabled veterans, recently separated veterans, Vietnam era veterans, or any other veterans who served on active duty during a war or in a campaign or expedition for which a campaign badge has been authorized) in any of its programs or activities. University policy is intended to be consistent with the provisions of applicable State and Federal laws. Inquiries regarding the University's nondiscrimination policies may be directed to the Affirmative Action/Staff Personnel Services Equal Opportunity Director, University of California, Agriculture and Natural Resources, 1111 Franklin Street, 6th Floor, Oakland, CA 94607-5200, (510) 987-0097. U.S. DEPARTMENT OF AGRICULTURE, UNIVERSITY OF CALIFORNIA AND SAN BENITO COUNTY COOPERATING TREE TOPICS NEWSLETTER JULY 21, 2009