Issue link: https://read.dmtmag.com/i/506700
www.goodfruit.com GOOD FRUIT GROWER MAY 15, 2015 45 adult mealybugs and their egg masses also differ in appearance. Apple mealybugs begin to overwinter as second- instar nymphs and emerge in mid-March or April. They continue to develop into adults and, after mating, the females lay egg masses, from which crawlers emerge about June. Mealybugs are challenging to control because they are protected by cottony secretions, Brosi said. And, if mealybug populations are low, the insects will be con- centrated in the tops of the trees, where they are difficult to see. "If you're not on a ladder, you may not know you have it, and it may be transmitting the virus," she warned. Controls Brosi and Beers tested several approaches to con- trolling the mealybugs: delayed dormant pesticide applications to intercept overwintering females; sys- temic petalfall applications to target crawlers; and foliar summer sprays timed when 70 percent of the crawlers are estimated to have emerged. At the delayed-dormant stage, a combination of Lorsban (chlorpyrifos) and oil worked better than diazinon and oil or oil alone. At petalfall, a soil drench using Admire (imidacloprid) or a foliar application of Ultor (spirotetramat) and oil reduced mealybug populations somewhat. Admire, Actara (thiamethoxam), diazinon, and Centaur (buprofezin) were tested as direct foliar sprays. Brosi said the growth regulator Centaur, which prevents the mealybugs from molting to the next life stage, was not as effective as diazinon in controlling the insects and might work better at the delayed-dormant stage. They will test it again this year. Also, this year, the researchers will explore organic control options, including repeated applications of horti- cultural and neem oils. There is also a parasitic Anagyrus wasp that might provide some control. Brosi said researchers will also look at how long it takes for mealybugs to acquire the virus from infected trees and how infected mealybugs transmit little cherry disease to healthy trees. They will sample orchards with a history of little cherry disease to see how far and how fast it spread and look at strategies for controlling the disease and stopping it from moving from orchard to orchard. In addition, they will survey leafhoppers in cherry orchards infected with Western X disease. • COURTESY OF WSU Unlike the apple mealybug, the grape mealybug adult has WDLOV$QGZKHUHDVWKHDSSOHPHDO\EXJGHYHORSVWKURXJK only one generation a year, the grape mealybug has at least WZRJHQHUDWLRQV • Enter different row spacings: the controller automatically maintains your rate per acre. • Compensates for changes in ground speed. Automatic Rate Controller Option 400 gallon TTN profile Powerblast 400 gallon wheel-well Pulblast • 52" outside tire width w/11Lx15 tires • adjustable width wheel centers made in made in u s a u s a made in u s a Rears Airblast Sprayers POWERBLAST PULBLAST Interchangeable axial flow fans to match blade pitch and air volume to your application and horsepower. Electric fan clutch Rears Constant Velocity Hitch powers through 90° turns Rears centrifugal pump and Rears gearbox: manu- factured by Rears for more than 40 years. Simple pressure adjustment to maintain accurate calibration in different row spacings. This is a time tested design for a wide range of applications. Variable pitch fans available in 28" & 36" dia. 100 - 600 gallon units with tank profiles for your application. Rears Constant Velocity Hitch available for most Pul-Blast models Piston actuated diaphragm pump or Rears centrifugal pump. Heavy Gauge Stainless Steel Construction Spray tank and all tank hardware Tower casement, shrouds, steps Manifolds, louvers, air doors Fan and blower housing Agricultural Equipment Dealer information 800.547.8925 CHERRYBLOWER 15° Towers bring the nozzle closer to the spray target. Tower height and profiles to match your application. Tune air volume: adjustable air doors independently control target zones Match Rears' aggressive air delivery engineering to your application with Vertical Wall, Over-the-Row, or Grape Elbow towers.