WEEK 13:  Early earworms; diamondback overlap РFULL REPORT HERE

  • Diamondback Moths are one of the smallest crop pest moths one is likely to encounter, but damage can be extensive. Part of the problem is their capacity to reproduce quickly, which leads to population buildup in a very short time. This is temperature-dependent and if not monitored, can catch growers off guard.
  • Corn Earworm is normally considered a late-season pest, but trends so far this year suggest a pattern similar to 2014, which resulted in a boom of moths in August, just as corn is silking. Larvae feed on corn silks and burrow into the ears. The resulting damage and frass (insect poop!) can cause delays in processing, or reduction of fresh-market value. This page shows how to identify corn earworm adult moths.
  • VegNet was featured in the July-Aug issue of OSU Linn & Benton Cty Extension’s Newsletter! Click photo to read the article.

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WEEK 5: First of two looper flights. Read the full report HERE.


The most notable trend this week is the sharp rise in looper activity. As seen in the graph below, 2016 levels (blue bars) were well above the historical norm (gray shaded line), and they remained that way throughout the season. This early 2017 peak (orange dot), while alarming, just means we’ll need to keep an eye on activity. It is the 2nd flight (Jul-Aug) that causes the most damage, because larvae and pupae contaminate crops headed for the processor. A contaminated crop can mean load rejection.

Home gardeners should be wary of looper levels, because larvae feed on a variety of crops including lettuce, tomatoes, peas, and other garden favorites. If you are concerned about defoliation, begin scouting between May 18th and 23rd. Look for ‘windowpanes’ or ragged holes, depending on how big the larvae are.

Processed vegetable growers are mostly concerned with looper flights near button-stage, as the main concern of this pest is contamination.

Looper larvae are light green with a white lateral stripe down each side, and display characteristic movement¬† – ‘looping’ along the leaf surface by gathering the rear legs to meet the front legs and then extending forward. More info on loopers is available here.