WEEK 15 full report available here:

  • Black cutworms will be large now, and can cause major root damage in corn. Consult the PNW insect management handbook for possible rescue treatments.
  • Diamondback pressure is still very high at remaining production fields.
  • Corn earworm – If chemical controls are needed, they must be applied before larvae move into developing ears.

As one of Oregon’s top 5 commodities, the fact that grass seed harvests are having an insect problem is a big deal.

Reports of caterpillars in grains and grasses are on the rise. PHOTO CREDIT: Steve Silbernagle

Over the past few weeks, seed has been arriving at the cleaner with high incidences of contamination by an unknown caterpillar. Wheat processors also are affected.

Based on timing and just a few photos, I have a good guess about what this is. Looking forward to getting some samples ASAP!

Please contact me if you’d like more information.

 

 

…Yes, that’s right – MOTHS!

As in..not quite the attention-grabbing, human-adored, delightful critters known as butterflies, but we are here today to petition that moths are just as important!

National Moth Week celebrates the beauty, life cycles, and habitats of moths. “Moth-ers” of all ages and abilities are encouraged to learn about, observe, and document moths in their backyards, parks, and neighborhoods. National Moth Week is being held, worldwide, during the last full week of July (which is JULY 17-25th, 2021 = 10th annual!).

CLICK HERE for the 2021 Website and Event Map

NMW offers everyone, everywhere a unique opportunity to become a Citizen Scientist and contribute scientific data about moths. Through partnerships with major online biological data depositories, NMW participants can help map moth distribution and provide needed information on other life history aspects around the globe. More information can be found here.

Search the map to find an event near you, (2017 text) but I will tell you – we are the only one in Oregon so far! We hosted a booth at the Farmer’s Market to get the word out, and it was a huge success. There is also a moth walk planned for July 22nd, co-sponsored by Oregon State Arthropod Collection (OSAC) and Greenbelt Land Trust. More info here. UPDATE: EVENT FULL!

OSU Faculty hosted an informational booth to increase awareness about moths: “the good, the bad, the beautiful and fascinating” PHOTO CREDIT: D.Botta

Better yet, create your own backyard mothing event! This document has some great tips on how to view and photograph moths. Then comes the fun part! Upload your findings to iNaturalist.org or a similar service. You do not need to be able to identify the species, others will help!

Good Luck, Have Fun, and Thanks for Your Help promoting and documenting this important group of insects!!

WEEK 14:

    • The 2nd generation of 12-spot beetles has emerged, and activity will likely remain high through September. Sweep fields with a sweep net to accurately assess population levels. Take a minimum of four samples (ten arcs of the net per sample) from different parts of the field. Beetles tend to concentrate on field edges. At this time of year, adult beetles are pests within snap bean and squash fields. They feed on folliage and developing pods.

     

    • There has been a boom of adult diamondback moths detected in pheromone traps. Development will be rapid under warm temperatures. Intensify field scouting so that treatments can be applied to avoid contamination.

    Read the full pest report HERE and subscribe to receive alert updates.

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WEEK 13:  Early earworms; diamondback overlap – FULL 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.

Thanks for reading! Be sure to subscribe to receive alerts and updates.

….Cutworms and armyworms, that is. Many studies report increased activity of these pests in years following record rainfall, and moisture dependency is common. This simply means that more eggs hatch if there is sufficient moisture in the soil.

For more info about cutworm ID, activity, and more,

please visit our other OSU blog:

Cutworm Central


Some species I have noticed on the rise over the past few years:

Spodoptera praefica is native to the Western U.S. It is considered a generalist feeder. Larval feeding causes extensive defoliation of leaves and also fruit damage. As the name implies, these worms are gregarious (feed in groups), and therefore can cause extreme damage.

Host plants include: alfalfa, asparagus, bean, beet, cabbage, carrot, corn, clover, lettuce, onion, ornamentals, pea, potato, wheat, and many others.


Apamea cogitata is considered a pest of grasses and grains (Poaceae). It is a cutworm, and has one generation per year, usually peaking in mid-July. This species is widespread in the Northwest. One of the identifying characteristics is a pink-hued fringe on the margins of the hindwing.

WEEK 7:  Flea beetles above, rootworms below, loopers everywhere

Let me explain:
  • Flea beetles invade fields rapidly, and can cause substantial damage to newly emerged leaves. Scouting is simple, thanks to the characteristic leaf damage. See photos and learn more here.
  • Rootworm is the common name for larval Diabrotica beetles. They feed underground, but can be distinguished from maggots by the presence of thoracic legs and a brown sclerotized plate just behind the head.

Rootworm. PHOTO CREDIT: Ken Gray, OSU

  • Cabbage Looper moths continue to be very abundant in the landscape. There is no diapause in this species, so 6-7 generations per year are possible if environmental conditions are suitable. Although trap counts are way above normal, the effect on crops has yet to be determined, and depends on a variety of factors. We will be discussing some of these in the weeks to come.

Read the full pest report HERE and subscribe to receive alert updates.

WEEK 6: Read the full report HERE

* Continued pressure of cabbage loopers. An outbreak occurred in the Valley in 2008, when trap counts reached 100+ per day. Review last week’s post for details, interpretation of looper flights, and recommendations for scouting.

* A diamondback moth ‘point-concern’ for the Corvallis location. More data will be available in the coming weeks.

* True armyworms (M. unipuncta) are not traditionally monitored by VegNet, because damage is most notable in grasses and forage crops. However, feeding on peas, beans, and brassicas can occur in outbreak years. Visit the armyworm page for more info.

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.

WEEK 4: Moth movement is low, rootworms in the landscape.

Don’t worry if you’re getting a late start to the planting season. So are the bugs. Many of the pest moth species we track are LOWER than normal for this time of year.

You may start to notice those familiar 12-spot beetles around, particularly on the dandelions in your yard or garden. These are the overwintered females, looking for suitable egg-laying sites (seedling corn, cucumbers, beans).

Check out this week’s full report HERE, and subscribe to receive VegNet highlights straight to your inbox!

**Thanks for your patience as I continue to build the rest of this site**