While none of us have a crystal ball, especially in agriculture, I thought it might be fun to offer some thoughts / warnings of how this year might look for insect pests of vegetables. I predict* ……

  • “Flea beetles will be rampant.” In the spring, adult flea beetles emerge from overwintering, and are already causing some problems in radish. We’ve been told by both local and regional sources that it’s going to be a hot and dry summer = flea beetles’ favorite weather. I suggest early and often scouting in brassica crops. Starting now, begin to scout weedy areas around fields. Once the crop emerges, or shortly after transplanting, focus efforts on field edges. It may be necessary to scout daily – yes, daily. Be aware that these insects are easily disturbed (they jump), sticky traps placed ~10″ off the ground can help assess activity – place them near edges. You’ll recognize the distinctive ‘pitting’ on cotyledons and true leaves. Check stems for signs of damage as well, just above the soil surface. For more information, see the flea beetle pest profile page.

  • “Wireworms are a cryptic foe we should get to know.” They are a common problem in grass and potato production. Adult click beetles do not live for very long and do not cause damage. Larvae (wireworms), on the other hand, live for 2-6 years and damage can be extensive. Before planting, especially if you are coming out of a grass rotation, take my advice and place a few bait traps to assess larval activity. Instructions and more information is available at the wireworm pest profile page.

  • “Every other year, cabbage loopers cause fear.” Ok, I admit, this one is just a stretch to fit the rhyme scheme. However, it is true that in the Willamette Valley, we have had major looper outbreaks in 2017 and 2019… so 2021 is a possibility. Trap count data will be available soon.

* PLEASE NOTE: these are merely educated guesses. In fact, part of the fun of monitoring insects is that they are truly so unpredictable!

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Over the past few days, I have seen 300+ cabbage looper moths in traps next to fields that aren’t even out of the ground yet, and been texted twice about flea beetle damage. It seems it will be a busy year for brassica pests!

cone trap with about 60 visible looper moths inside
First indication of probable outbreak – May 8th 2019: too early to see this many

All the more reason to subscribe! Stay informed by clicking here. We do not share your information, and many of the pests we report on have wide host ranges, which means the data are relevant for home gardens, nurseries, and many commodity crops.

An example pest report can be seen here: https://mailchi.mp/f504f1497d5b/pest-report-week-4

Update: May 16th

…An uncommon phrase to hear in agriculture, but recent floods will have a dramatic effect and have already caused an estimated $12.5 billion dollar loss in the Midwest. Impacts include crop damage, inability to access fields to work ground or plant, and water contamination.

Here at home, the mainstem of the Willamette River and its tributaries (Long Tom, Mary’s, Callapooia) are in huge swells, with property flooding and road closures abundant. For current updates, check Benton and Linn County webpages or ODOT TripCheck.

High Water 02
A South Willamette Valley property was flooded Tuesday morning SOURCE: Andy Cripe, Mid-Valley Media / Corvallis Gazette-Times

From an insect pest point-of-view, the changes that may come about are uncertain, but I will be keeping a close ‘eye to the ground’. Flooding could cause mortality for some species (onion bulb mite, beetles, sawflies), promote growth in others (armyworms, mosquitoes), and have little effect on bugs that overwinter in sheltered areas (BMSB and ladybugs).


 

‘Twas a dreary day when I could finally get out to our research farm to assess damage to fields. However, our farm manager is resilient and those that have lived here longer say it’s “not that big of a deal”. I guess when you live in Oregon with 300 days of rain, you make your own mental sunshine.

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.