Category Archives: Insect

Thrips are no worse than usual in Virginia and so far, treatments are working

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Hearing that thrips populations are larger than normal in the southeastern states has caused some concern in Virginia. For the past several years our ‘normal’ in terms of thrips numbers and plant damage to cotton and peanut seedlings has been higher than most of our neighbors to the south. Worse than ‘normal’ would be really challenging. This is the first week (May 14-18) that we have been able to systematically assess the thrips situation in our many cotton and peanut thrips field trials, as we finally have 1st true leaf cotton and emerged peanuts. To evaluate the thrips species and abundance, we sample 5 cotton seedlings per plot and in peanuts, 10 unopened terminal leaflets per plot. We rinse the adults and immatures from these plants/leaves and count them under a microscope. We also identify some number of the adults to species, which allows us to keep track of any species shifts that could indicate a problem.
This week’s samples are showing numbers that are pretty much in line with what we would expect for this time of the year. In cotton, we are finding about 10-18 adult thrips per 5-plant sample (2-3 per plant) and about that same number of immatures. In peanuts, we are finding about that same number of adults, but fewer immatures. These numbers are typical of the first sample in May. By next week, we will see an increase in the number of immatures to levels that have historically reached as many as 130-160 per 5 cotton seedlings and as many as 60 in 10 peanut leaflets. These immatures are the stage responsible for most of the plant damage. We are just beginning to see the effects of feeding on the plants and by next week, it will be no problem sorting out which treatments are performing best.
A positive observation—so far we are seeing good performance with the treatments that include Admire Pro, Thimet, liquid Orthene in-furrow, CruiserMaxx Peanut, Avicta CP and Aeris/Poncho Votivo in cotton and many others. It is especially important to note that so far, we have not detected any peanut stand emergence delays with Orthene/Acephate liquid in-furrow treatment, and we have several in our field trials.
We will continue to post updates as ‘thrips season’ progresses—and don’t forget that many of these thrips trials will be featured on our annual early season field tour on Tuesday, June 5 beginning at 9 am. We will post the flier next week.

Controlling brown marmorated stink bugs in sweet corn

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I was contacted recently by a VCE Agent in Frederick Co. Mark Sutphin about my recommendations for stink bug bug control in sweet corn. Frederick Co., VA is one of the counties that has very high densities of the invasive brown marmorated stink bug. After sending him my reply, I thought that others in Virginia may also benefit from this information. So here it is below:

Fortunately for sweet corn producers, unlike tree fruit growers, BMSB should not cause any drastic changes in chemical control strategies unless the grower is relying primarily on transgenic Bt sweet corn for worm control.
Bt will not control stink bugs. Most of the insecticides that growers are already spraying on sweet corn should control BMSB. These include the following below:

beta-cyfluthrin – 1.6-2.8 fl oz/A Baythroid XL
bifenthrin – 2.1-6.4 fl oz/A Bifenture (or Brigade, Sniper, or OLF) Not labeled in coastal counties
chlorpyrifos 1-2 pts/A Lorsban 4E (or OLF)
chlorpyrifos + gamma-cyhalothrin – 13-26 fl oz/A Cobalt
cyfluthrin – 1.6-2.8 fl oz/A Tombstone (or OLF)
gamma–cyhalothrin – 2.56-3.84 fl oz/A Proaxis
lambda-cyhalothrin – 1.28-1.92 fl oz/A Warrior II or 2.56-3.84 fl oz/A Lambda-Cy (LambdaT, Silencer, or OLF)
lambda-cyhalothrin + chlorantraniliprole – 6-9 fl oz/A Voliam xpress
methomyl – 0.75-1.5 pts Lannate LV
permethrin – 4-8 fl oz/A Permethrin 3.2EC (Perm-UP, Pounce 3.2EC or OLF)
zeta-cypermethrin – 2.24-4 fl oz/A Mustang MAX (or OLF)
zeta-cypermethrin + bifenthrin-Not labeled in coastal counties 4.5-11.2 fl oz/A Hero EW

Click More News to download a copy of the insecticide performance report based on our research on vegetable crops in Virginia in 2011.
In the western portions of Virginia, probably applications twice per week during silking and until harvest should control them even under heavy pest pressure. In eastern counties, insecticide applications at least 3 times per week are probably needed to control both corn earworm and the BMSB.

Best regards,
Tom
Additional information: summary-of-insecticide-performance-on-bmsb-nov2011-docx

2011 Vegetable arthropod Pest Management Research Summary

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The 2011 Vegetable Entomology Research Summary is available online at the following link: http://pubs.ext.vt.edu/ENTO/ENTO-1/ENTO-1.html.

Highlighted are Dr. Tom Kuhar’s research trials conducted in 2011 on key vegetable crops and insect pests, including a number of field experiments and laboratory assays on the brown marmorated stink bug.

Vegetables added to the Belt insecticide label

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Bayer CropScience recently announced that vegetables have been added to the Belt insecticide label. The insecticide product Synapse, which also contains the potent-lepidopteran active ingredient flubendiamide, will be phased out. Belt will be the product for both cropping systems. Existing supplies of Synapse should be sold, and growers can continue to use that product. Bayer Cropscience is also offering price reductions for the product. Click more to download the new Belt label. Additional information: newbeltlabel-withvegetablesadded-pdf

Ames Herbert’s 2011 research summary book now available online

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Ames Herbert’s 2011 “Insect Pest Management in Virginia Cotton, Peanut, and Soybean” is now available online at: http://pubs.ext.vt.edu/AREC/AREC-7/AREC-7.html
This document summarizes thrips, corn earworm, stink bug, southern corn rootworm, and other insect pest trials in the above crops. It also includes the results of the 2011 field corn survey, soybean insecticide use survey, and black light trap captures.