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New article about SWD
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Author:  John S [ Tue Mar 29, 2011 11:03 pm ]
Post subject:  New article about SWD

Lee- are you listening?

This is an article from another internet forum about fruit. Originally it was an article translating ideas from the Japanese and was printed at UC berkeley, I believe.

2010 Spotted Wing Drosophila
Recommendations for Sweet Cherry
Robert A. Van Steenwyk
Dept. of E.S.P.M., University of California, Berkeley
These recommendations are derived from translated Japanese research articles on spotted
wing drosophila (SWD), preliminary trapping data from Janet Caprile (UCCE Farm
Advisor – Contra Costa County) and Bill Coates (UCCE Farm Advisor- San Benito
County), insecticide efficacy data from Mark Bolda (UCCE Farm Advisor - Santa Cruz)
and fruit maturity susceptibility data from Jana Lee (USDA – Corvallis, OR). Control
procedures are conservative due to the lack of insecticide efficacy data on California
cherries and damage experience by cherry growers this past season. These are our best
guesses with limited data and we expect the recommendations to change over time.
Monitoring: Place a commercial bucket style trap or a 1 qt. plastic container with screen
(3/16 inch holes hardware cloth) on the top and bait the trap with 1 inch of apple cider
vinegar. The 3/16 inch holes will limit the number of large moths, flies and bees
captured in the traps. The plastic containers are about 50¢ each and apple cider vinegar is
about $3.00/gal from Smart & Final. Replace the vinegar weekly (remove spent bait
from the orchard – do not dump the spent bait on the ground in the orchard). Place trap
about 3-5 ft. off the orchard floor and monitor twice weekly from first color change (light
green to straw) until completion of harvest. Count only flies with spots on the tip of the
wings (male SWD). OptiVISOR (optical glass binocular magnifier) will aid in the
identification of flies. If any SWD are found in the traps, take control action immediately
(see insecticide control below).
Generation time: One generation requires 338 DD with a lower threshold limit of 48° F.
The table below shows the approximate generation times throughout the spring and
summer in the northern San Joaquin Valley (Linden) and the central coast (Hollister).
These generation times are based on 30-year average temperatures from the UC IPM
weather network and will vary depending on current temperatures.
Approximate generation time for SWD by date infestation and location
Number of days until adult emergence
Infestation date
(egg laying)
San Joaquin Valley
Central Coast
April 1 28 days 34 days
May 1 20 days 29 days
June 1 15 days 22 days
July 1 13 days 18 days
Cultural Control: If conventional insecticide treatments are not an option (organic
growers), and if fruit from pollinizer varieties matures earlier than the main variety and
the pollinizer fruit will not to be picked and sold, then pick and remove pollinizer fruit at
least one week before harvest of the main variety. This will prevent the SWD from
emerging from the pollinizer fruit during the main variety harvest. Fruit removal is a
critical control step for organic growers because of the lack of known effective organic
insecticides. Conventional growers can suppress SWD on pollinizer fruit by insecticide
applications (below).
Chemical Control: Begin applications when the pollinizer or the earliest variety in the
orchard, changes color from pink to red. Repeat applications at 7 to 10 day intervals until
harvest with one of the materials listed below. From Jana Lee and from Japanese
literature it appears that the SWD will infest ripe cherries of red to mahogany color.
Also, from the Japanese literature it appears that 3 or 4 applications are required to
control the pest and that the organophosphate and pyrethroid insecticides are effective for
one to possibly two weeks. Observe all pre-harvest intervals (PHI) and re-entry interval
(REI) periods and rotate between materials of different chemical classes between
applications to slow the development of resistance. At this point in time, we are
recommending adding Nu-Lure bait at 3 pt/100 gal with a final spray volume of 50
gal/ac. Do not include surfactant with Nu-Lure. Nu-Lure should be removed during
post-harvest washing.
Trade Common Chemical
Name Name Class a PHI REI Rating b
GF-120c Spinosad SPIN 0 days 0 hr 4
Malathion Malathion OP 3 days 12 hr 1
Ambush/ Permethrin PYR 3 days 12 hr 2
Renounce/ Cyfluthrin PYR 7 days 12 hr 1
Baythroid Beta-Cyfluthrin PYR 7 days 12 hr 1
Provado Imidacloprid NEONIC 7 days 12 hr 3
Leverage Beta-Cyfluthrin PYR + 7 days 12 hr 1
(Baythroid + Imidacloprid NEONIC
Entrust/ Spinosad SPIN 7 days 4 hr 3
Delegate d Spinetoram SPIN 7 days 4 hr 1
Actara Thiomethoxam NEONIC 14 days 12 hr 3
Asana Esfenvalerate PYR 14 days 12 hr 2
Warrior II Lambda- PYR 14 Days 12 hr 2
a The chemical classes are: SPIN is spinosyns, OP is organophosphates, PYR is
pyrethroids, NEONIC is neonicotinoids.
b The rating scale is: 1= control for 7 to 14 days, 2 = control for 3 to 7 days, 3 = control
for 1 to 3 days, and 4 = control for only 1 day.
c GF-120 is slow acting and does not have knock-down activity but will suppress
population over time.
d There is no MRL established for Delegate in Japan, Korea or Taiwan. Please consult
your packer/shipper for export implications

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