Mar 6, 2020
The Key to Controlling Spotted Wing Drosophila

(Sponsored) Systematic scouting is critical to effectively controlling spotted wing drosophila in cane berry fields and preserving marketable yields.

“Our No. 1 pest in brambles is spotted wing drosophila,” says Kelly Hamby, an entomologist with the University of Maryland. “Early detection is key to effective control.”

Native to Southeast Asia, the invasive pest has spread across the United States where it targets the ripening fruit of blackberries, blueberries, cherries, strawberries and raspberries.

Hamby recommends regular, careful scouting for insect and mite pests with at least one dormant scouting and additional checks as regularly as possible during the season, especially between petal fall and harvest. Intensive scouting should also occur along field edges and in known problem areas.

“With a new population every 10 to 15 days and each female laying approximately five eggs per day, spotted wing drosophila can quickly become a problem.”

In the Mid-Atlantic region, the spotted wing drosophila (Drosophila suzukii) larvae first appear in early July, predominantly in raspberries and blackberries.

“Spotted wing drosophila have small, white legless larvae with no apparent head, and damaged fruit often feels soft and leaks juice,” Hamby says.

In efficacy rankings, Delegate® WG insecticide has performed well in the battle against spotted wing drosophila. “We see good to excellent control with Delegate,” Hamby says.

“Including Delegate in a season-long management strategy with multiple modes of action enables better control of spotted wing drosophila and other damaging pests at a time in the season when control is critical to fruit quality,” says Nathan Alonso, Corteva Agriscience product manager.

Delegate contains spinetoram — an innovative active ingredient that delivers fast knockdown of a wide range of yield-robbing insects, including spotted wing drosophila, leafrollers, thrips and many worms.

Delegate effectively controls insect pests through contact and ingestion. It also exhibits translaminar movement in the plant or movement from the upper surface of the leaf to the underside of the leaf so it can control insects outside the direct line of spray. As a Group 5 insecticide, Delegate offers a unique mode of action that is ideal for insecticide resistance management. It has minimal impact on beneficials and does not flare mites.

Other keys to improved control of spotted wing drosophila include:

  • Employ seven-day spray intervals with insecticides offering residual activity.
  • Rotate modes of action to minimize potential resistance development.
  • Consider reapplication of insecticides after significant rainfall.
  • Ensure good coverage of crop protection products, especially insecticides.
  • Monitor and catch pest problems as early as possible with regular and thorough crop scouting.

Other fruit-feeding pests to scout for in the critical time between petal fall and harvest include true bugs, caterpillars, wasps and beetles.

Hamby reminds fruit producers, “Insecticides should be applied before there are open blooms to avoid toxicity to pollinators.”

Learn more about how Delegate® WG insecticide can help battle pestsin your berry crops by visiting

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