Walnut husk fly may not be any larger than the average housefly, but it can cause a disproportionate amount of damage to an unprotected walnut crop.
A walnut husk fly infestation can result in deformed and discolored kernels, increased mold growth and a substandard yield. Walnut husk fly can also stain the shell, affecting a crop’s marketability.
Monitoring is an extremely important aspect of walnut husk fly control, and trapping is the key element in this process. PCAs and growers should set traps among the rows with a goal of catching females and squeezing the abdomen to determine whether they are carrying any eggs. If they are, it’s time to spray.
PCAs and growers should consider taking a program approach to walnut husk fly control. Alternating between different modes of action is a critical component of an effective resistance management program and is the best method for maximum control of walnut husk fly and other tree nut pests.
Belay® Insecticide and Danitol® Insecticide from Valent U.S.A. Corporation represent different chemical classifications and make an ideal pairing for an effective two-spray program.
Belay provides exceptional control of walnut husk fly for up to 14 days, quickly reaching pests where they feed as a result of its translaminar movement and killing them by contact and ingestion contact.
Danitol likewise delivers highly effective control of walnut husk fly. It also offers a notably short 24-hour restricted entry interval and does not flare mites like other control products.
Pairing an insecticide like Belay with a lure such as Nu-Lure® Insect Bait can enhance the effectiveness of a spray program. By drawing the walnut husk fly in, the lure can deliver a lethal dose of insecticide and help mitigate an infestation before it gains steam.
Note that the higher concentration of the attractant, the better in terms of attracting flying walnut husk flies. To achieve a high concentration, PCAs and growers spray every other row with an insecticide rather than all rows.
Whether Belay or Danitol is employed for the season’s first walnut husky fly spray, use a different mode of action for the second spray 3-4 weeks later if warranted. To determine whether a second spray is needed, place additional traps high up in the trees. If females with eggs are again present, residual from the first application has waned and harvest is three or more weeks away, proceed with the second spray.
To learn more about Belay, Danitol and the Valent portfolio of tree nut products, visit www.valent.com/belay.