Online Degree Day Presentation Available from UC IPM

Written by: Jodi Azulai, UC Statewide IPM Program   To accurately time insecticide treatments see our online presentation about using degree-days for pests in fruit and nut trees. While we can’t control heat waves such as the recent one, we can measure daily temperatures to protect our orchards from several important insect pests such as navel orangeworm, San Jose scale, orange tortrix, and codling moth.

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Speed Doesn’t Kill (Part Two)

Ken Giles and colleagues have been reworking some of the old research on spray rigs, coverage, and insect control. Their most recent project reviewed ground speeds on insecticide coverage, but with a new twist – they incorporated spray efficacy (NOW control) into the control. In their most recent study – reported in the 2011-2012 Annual Research Report of the Almond board of California – they showed that coverage did not differ between two rig speeds, but survival of navel orange-worm (NOW) eggs decreased when Altacor was applied at the slower speed. The study was conducted at Nickels Soil laboratory near Arbuckle, CA. Sprays were made at either 1.8 mph or 2.4 mph using Altacor insecticide, R-11 non-ionic surfactant, and micro-nutrient tracers for disposition analysis. Applications were made with 100 gallons/acre. This volume was chosen because previous studies has shown it to the most effective volume in reducing insect infestation/damage. Disposition was measured using steel cylinders which had some resemblance of almonds within the trees. Leaf punches were also taken to measure disposition on leaves. After spraying, nuts were collected from the upper and lower canopy and NOW eggs were placed to determine efficacy of the pesticide application. Nuts were collected 1 DAT and 14 DAT. Spray deposition was not affected by tree location (upper v/s lower) and speed. Secondly, there were no difference between NOW survival in the nuts collected 1 day after treatment among the tree locations and speed. 14 days after treatment, however, significant differences in NOW survivability were found in the upper canopy of the tree – the slower rig speed reduced egg viability by 95.75% compared to 87.12% reduction at the faster speed. In other words, NOW eggs were 3 times more likely to survive in the upper canopy when the pesticide was applied at the

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Leaffooted Plant Bug

I have been several calls in regards to leaffooted plant bug (Leptoglossus clypealis and L. occidentalis). Damage has been reported from various areas of the county, with significant damage observed within some blocks. Leaffoted plant bugs get their name from the leaflike features found on the back legs of the large nymphs and adults. Adults are about 1 inch long and have  a yellow or white zigzag line across their back. Females lay eggs in strands which are often found on the sides of almonds or pistachios.

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NOW Biolure – 2 Different Moths in Trap

I have been hearing multiple reports of high counts of Navel Orangeworm (NOW) moths trapped with the new Suterra Biolure. We have placed our traps and have had high trap counts as well. In our liners, however, we have found two different moths – one being NOW  (Amyelois transitella) and the other being a meal moth (Pyralis farinalis). Both of these moths are within the same family (Pyralidae) and can be confused. 

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Managing Mites in Almonds with Abamectin

Written By David Haviland, Kern County UCCE Entomology Advisor For more than a decade abamectin has played a key role in mite management programs in California almonds.  When applied properly, early-season abamectin treatments typically provide good mite control through hull split, and in some cases throughout the season.  Unfortunately, recent reductions in the cost of abamectin have led to unnecessary use, and sometimes abuse, of abamectin-based products.  This has led to more and more cases of unsatisfactory mite control at a time when mite management has taken an elevated importance due to increased adoption of pyrethroids for control of navel orangeworm.  This article covers several considerations that should be made while using abamectin to insure that it works effectively and consistently. 

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Are the “Wild” Almonds Near You Harboring Navel Orangeworm?

Written by Bob Johnson – Almond Board UCCE Farm Advisor Intern As I drove down a county road near Arbuckle in the south Sacramento Valley, I noticed a significant number of mummies in the “wild” almonds growing in the ditch. With winter sanitation becoming much of the focus in NOW control, I wondered how many worms were overwintering in that patch of roadside almonds with commercial almond orchards on both sides of the road.  I pulled over and checked.  Of the trees that contained mummies, if it had a soft shell it was packed full of NOW. Dave Doll’s blog post in November stressed the importance of winter sanitation and presented recent data from Brad Higbee (Paramount Farms) and Joel Siegel (USDA-ARS). Their data provides suggested sanitation standards of no more than 2.0 mummies per tree in low pressure areas and less than 0.7 mummies per tree in higher pressure areas, to keep NOW damage below the 2% industry standard. What about one tree that contains hundreds of mummy nuts and is just on the other side of the fence? If sanitation is your goal, a quick drive around to identify trees with significant mummies along the roadsides near your orchard might be worth the time. Not every “wild” almond presents a problem, as some are hardshells and most contain no mummies, but you might consider removing those that do.

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New video for managing almond pests using the year-round IPM program

Not sure what you should be doing to manage pests for the upcoming season?  Check out the year-round IPM program for almonds on the UC IPM web site. Need help using it?  UC IPM has just published an online video to help you manage almond pests using the year-round program. How to Manage Almond Pests Using the Year-Round IPM Program is a narrated how–to guide written for growers, PCAs, and others who work in almonds, showing what needs to be done throughout the season to stay on top of pest problems.

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IGRs at Bloom: Bad Idea?

Recent IPM practices have advised the use of IGRs (*1) diflubenzuron (Dimilin) at bloom time to control PTB larvae. This timing has been shown to be highly effective. Work by several scientists, including researchers from USDA-Tuscon Haydeen Bee Research Lab, Ohio State University, Oregon State University, BASF, and UC Davis (*2), however, has suggested that this may not be the best timing for bee health. Below is a email sent by Dr. Mussen for distribution. It basically concludes that the bloom timing for IGRs may harm bees, and should be avoided if possible.  Delayed dormant and May spray applications of these products can and should be considered for PTB control. Email from Eric Mussen, UC Entomologist/Apiculturist:

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