Category Archives: Commodity

Eastern Shore Insect Pest Activity for Week ending Aug 26

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Click More to view the insect trap counts for various locations on the Eastern Shore of Virginia. Current counts as well as those from previous weeks are included. In summary corn earworm moth activity remains high in Eastville and Melf according to pheromone trap catches of approximately 50 moths per week. Beet armyworm moth activity is also peaking especially in Eastville.

Concomitant to this moth activity, we have been experiencing these pest larvae in multiple crops including soybeans, green beans, peppers, and tomatoes. Growers and crop consultants should still carefully monitor crops for these pests even if they have been sprayed previously.
Additional information: es-insect-trap-counts-8-24-10-5-xls

Corn earworms, loopers, green cloverworms and more in soybeans

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Although the corn earworm flight is still strong, we are not hearing of many fields with high numbers of worms. However, we are hearing of a lot of fields with pod-stage thresholds and many are being re-sprayed. Several folks have reported seeing newly hatched small worms but are waiting a few days before spraying to see how things develop. Holding off a few more days may mean the difference in having to treat a third time. There are a lot of fields that seem to be holding with no new earworms developing, especially the early planted fields. More infestations are being reported in later-planted double crop fields. This is a typical pattern as the pods in early planted fields are getting to the point where they are no longer attractive or vulnerable. Maybe this second infestation will not be as bad as we expected, but we have another week or two before we will know. Our advice is to keep checking fields at least every 5 days or so, until fields reach the R7 growth stage. As a side note, our pyrethroid testing of adult corn earworms is showing a gradual increase in the level of survivorship, now averaging over 40% for this past week (see the attached figure). Better consider one of the non-pyrethroid options.
We are finding (and hearing about) more soybean loopers. The most we have encountered is about 15 to 20 per 15 sweeps, but even at those numbers, the level of defoliation is not bad or to the point where fields need protection. This may get worse, or may not, depending on a lot of factors.
One of the oddest situations is the extremely large numbers of green cloverworms that are being reported in some areas. Folks are finding 30-40 and more per 15 sweeps and they are definitely working on the foliage. We always see cloverworms in soybean fields but never at these high levels. They are having to be controlled in fields with limited growth (due to slow growth during the hot dry weather).
Reports from Maryland are saying that brown marmorated stink bugs are inundating soybean fields in western and central Maryland. We have known about this pest for several years. It is a native of China, was first reported in Virginia in 2005 (one specimen) and has gradually increased in number. It has become established in Virginia and is now causing problems in vegetable a fruit crops. Soybean is one of its many host crops in China and as we feared, it is now moving into that crop. We have found a few in Virginia soybean fields, about 1 per 15 sweeps in a couple of fields. We do not know much about damage potential or control options but a lot of research is underway.
Additional information: cew-cypermethrin-aug-26-2010-ppt

Corn earworm moth black light trap captures for week ending 26 August

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Mean nightly corn earworm moth captures for 20-26 August 2010 were as follows: Petersburg (34), Prince George-Wells (10), Prince George-Lipchak (50), Southampton (68), Suffolk (18), Sussex (18), Essex (5), Northumberland (16), Richmond County (28). Please see the attached table for more information. Additional information: blacklight-table-10-doc

An update of the soybean aphid and brown marmorated stink bug monitoring program

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For August 16-19, Ed Seymore reported that surveyed fields in the following counties had little to no soybean aphids, with the exception of Gloucester in the Wood’s X area: Augusta (0), Albemarle (0), Buckingham (0), Caroline (1-5), Charles City (0), Clark (1-5), Culpeper/Fauquier (6-39) aphids/plant), Gloucester (150-249), Goochland (0), Henrico (0), King and Queen (0), King William (0), Lancaster (0), Mathews (1-5), Middlesex (0), Rockingham (0), and Shenandoah (0). The economic threshold for soybean aphid is 250 aphids/plant. Under ideal conditions, soybean aphid populations can double every 2 days. Very low numbers (about 1 per 15 sweeps) of brown marmorated stink bugs were detected in one soybean field in central Culpeper County.

Monday, August 23- A corn earworm alert

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A very large movement of corn earworm moths is taking place throughout much of eastern Virginia. I did some driving throughout several counties this past Sunday night and there were so many moths flying it felt like being in a snow flurry. Soybean and peanut fields are at very high risk to re-infestation of worms. Most fields were treated 2 weeks or more ago and are very susceptible to re-infestation. Calls have already started coming in with growers and crop advisors seeing this re-infestation. Here are several observations and recommendations. First, I think this fight is comprised mostly of corn earworm (less possibility of tobacco budworm), and I think they are coming out of our own peanut and soybean fields. Because of this, they may represent survivors from previous sprays so there could be even higher percentages with some level of pyrethroid resistance. My advice is to try to hold off on making applications for at least a 2 or 3 more days. By waiting, the moths will lay more eggs and more small larvae will hatch. Going too early in this flight cycle may mean yet another treatment. Of course, waiting too long will allow worms to begin feeding on pods. Worm must be 3/8 inch long or longer before they can feed on pods, and remember, we base our thresholds on these sizes-not the tiny worms. When you pull the trigger, go with idea that the best kill will be achieved having a non-pyrethroid in the mix. We have gone over those options several times. The newest option added to that list is Belt by Bayer CropScience. Belt is performing very well in our field trials at 3 oz/acre. The label goes from 2-3 oz. The 2 oz rate may be enough but we have not tested it. Belt is also showing some indication that it is providing good residual activity. Consero is also new and could present another good tank mix option. Consero is a co-pack of spinosad and gamma-cyhalothrin and is labeled at 2-3 oz/acre. Other non-pyrethroid standards are Larvin, Steward, Tracer and Orthene (which should only be used if tank-mixed with a pyrethroid).

Worms Continue to be a Threat on the Eastern Shore

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Heavy worm pressure is still being seen across the Eastern Shore. One field of sweet corn was assayed for baythroid resistant corn ear worms after showing 90% damage. This was after one spraying of Coragen followed by six additional treatments of baythroid. The results of the bioassay showed none of the worms were baythroid resistant. Only severe worm pressure would seem to be the cause. Corn ear worm and beet armyworm flights remain high especially in the Birdsnest/Machipongo area. Beet armyworms can also be found frequenting pigweed and lambsquarter around the edges of fields. Young corn on the station has been heavily damaged by fall armyworms and a few adults have appeared in the trap on station possibly presaging another flight of these destructive pests. Additional information: es-insect-trap-counts-7-30-10-8-18-10-xls

A second corn earworm-budworm moth flight and pyrethroid resistance, a perfect storm

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As predicted, we are in the midst of a second flurry of corn earworm and tobacco budworm moth activity. Some black light traps are catching even higher numbers than during the first flight. Moths are flushing from peanut, cotton and soybean fields. Each crop is presenting a different scenario in terms of risk to infestation and potential crop damage. I can almost guarantee that peanut and soybean fields will be re-infested with worms, and there is a very good possibility that the infestation will be a mix of both species.

PEANUTS almost never suffer economically from worm feeding, but growers will likely not tolerate the worms and tank mix some insecticide with a planned fungicide application.

SOYBEANS are a different story. This next influx of worms will coincide with pod development and fill. Many fields that have been drought stressed are getting some rain and plants are reflowering which makes them highly attractive to moths. I think pod thresholds will be met or exceeded in many fields and many will need to be re-sprayed. Most of these fields have already been treated, but in my opinion, and in the opinion of other soybean entomologists, no product offers more than about 7 days residual activity so any field treated more than 7 days ago will be completely vulnerable to worms. Another piece of the puzzle is the continued high pyrethroid resistance levels of corn earworm. As of this week, we have tested 1,903 moths and survivorship has climbed back to over 40% (see the attached figure). One sample this week reached 56%. Is this resistance level increasing because many of these moths are from the worms that ‘escaped’ the earlier pyrethroid sprays? Seems logical. The best control will need to incorporate a non-pyrethroid (Larvin, Lannate, Steward, Tracer, Belt). Another tank mix that seems to be working well where ever it is being used (the Delta states, Tennessee, North Carolina) is to add 6 oz of Orthene to a full pyrethroid rate.

COTTON may be the least attractive and least susceptible to this next influx of worms. The hot, dry weather has pushed cotton to cutout with many bolls already too tough to be damaged by worms. Much of the crop will be ready for defoliation within the next 3 weeks or so.
Without some top growth of new tender flowers, squares or small bolls, young worms will not be able to establish. And even if this top growth does become infested, it represents a very small proportion of the total yield, which makes controlling worms (the cost) a tough decision.
Additional information: cew-cypermethrin-19-aug-2010-ppt

Bayer Agrees to Terminate All Uses of Temik insecticide (Aldicarb)

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The U.S. Environmental Protection Agency and Bayer CropScience, the manufacturer, have reached an agreement to end use of the pesticide aldicarb in the United States. A new risk assessment conducted by EPA based on recently submitted toxicity data indicates that aldicarb, an N-methyl carbamate insecticide, no longer meets the agency’s rigorous food safety standards and may pose unacceptable dietary risks, especially to infants and young children.

To address the most significant risks, Bayer has agreed first to end aldicarb use on citrus and potatoes and will adopt risk mitigation measures for other uses to protect groundwater resources. New measures to protect shallow drinking water wells in vulnerable areas of the southeastern U.S. coastal plain and lower application rates will be immediately added to product labels for use on cotton, soybeans, and peanuts.

The company will voluntarily phase out production of aldicarb by December 31, 2014. All remaining aldicarb uses will end no later than August 2018. Additionally, EPA plans to revoke the tolerances (legal pesticide residues allowed in food) associated with these commodities. EPA did this to ensure we have the safest food supply possible.

Based upon current toxicological studies, aldicarb at levels higher than those typically found in food has the potential to cause various effects such as sweating, nausea, dizziness and blurred vision, abdominal pain, vomiting, and diarrhea.

Aldicarb is registered for use as a systemic insecticide and nematicide on agricultural crops, and is formulated and marketed solely as a granular pesticide under the trade name Temik. During the phase-out, the pesticide will continue to be registered for use on cotton, dry beans, peanuts, soybeans, sugar beets, and sweet potatoes. Aldicarb products are not intended for sale to homeowners or for use in residential settings. A restricted use pesticide, aldicarb may be applied only by trained, certified pesticide applicators.

The memorandum of agreement and the agency’s updated dietary risk assessment and supporting materials will be available in the aldicarb reregistration docket, EPA-HQ-OPP-2005-0163, and in the aldicarb Special Review docket, EPA-HQ-OPP-2006-0197, at regulations.gov.

The U.S. has a safe and abundant food supply, and children and others should continue to eat a variety of foods, as recommended by the federal government and nutritional experts.

More information: http://www.epa.gov/oppsrrd1/REDs/factsheets/aldicarb_fs.html

Update on the statewide soybean aphid and brown marmorated stink bug survey

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With financial support from the Virginia Soybean Board and federal funding for our state IPM program, our soybean scout Ed Seymore has begun to monitor about 30 soybean fields for soybean aphid and a new invasive pest species, the brown marmorated stink bug. From Aug. 2 to mid-August 2010, surveyed fields in the following counties had little to no soybean aphids: Augusta (0), Albemarle (0), Buckingham (0), Caroline (0), Charles City (0), Clark (0), Culpeper/Fauquier (1-5 aphids/plant), Gloucester (0), Goochland (0), Henrico (0), King and Queen (0), King William (0), Lancaster (0), Mathews (0), Middlesex (0), Orange (6-39 aphids/plant), Rockingham (0), and Shenandoah (0). The economic threshold for soybean aphid is 250 aphids/plant so these low numbers of aphids do not pose any threat at present. Very low numbers (about 1 per 15 sweeps) of brown marmorated stink bugs were detected in two soybean fields in central Culpeper County. Researchers are still trying to determine the extent and nature of brown marmorated stink bug feeding injury to soybean, but it will likely pose a risk if populations become established.