As of July 29, we have tested a total of 768 corn earworm moths in our pyrethroid AVT (adult vial testing) program. Although the percent survivorship is down somewhat from last week, we are still seeing greater than 20% survive (see the attached line graph). Could this mean that field failures are likely? Possibly, especially if worm populations are large. Our goal is to process as many moths as we can and post these weekly updates. We are also responding to calls from crop consultants, advisors and growers. We have one reported case of a ‘less than acceptable’ level of control in a peanut field. Could some of those surviving worms have been tobacco budworms, which are known to be more difficult to control with pyrethroids? Possibly, but it is almost impossible to distinguish between corn earworm and tobacco budworm without inspecting the moth parts of the worms under magnification in lab. We do know that budworms can be in the mix, up to 30% one year when we did a lot of worm IDs. Bottom line, this is the third consecutive year that local corn earworm populations are demonstrating high levels of pyrethroid resistance. Proceed with caution and consider non-pyrethroids especially in peanut or soybean fields with a lot of worms.
Additional information: cew-avt-jul-29-2010-ppt
Category Archives: Pest Group
Eastern Shore Insect Trap Counts for Week Ending July 23
Mr. Kyle Sturgis and Bill Shockley have embarked on a more extensive insect pest trapping effort on the Eastern Shore. Click more to view a spreadsheet of pheromone trap catch and blacklight trap catch from various locations on the Eastern Shore of Virginia. This same spreadsheet will include other locations and will add new catch numbers on a weekly basis. We are getting organized to deliver a more comprehensive picture of the activity of major agricultural pest insects on the Eastern Shore.
In summary the spreadsheet shows the first real rise in counts of both corn earworm and European corn borer in the Mappsville and Assawoman areas of the Eastern Shore. Activity in Eastville appears to be low. There have been no catches of either beet armyworm or fall armyworm so far. It is early for those pests, although a fall armyworm infestation in late planted corn was seen in Northampton County this week.
Additional information: es-insect-trap-counts-7-16-10-7-23-10-xls
Corn earworm captures for the week ending 22 July 2010
As Dr. Herbert mentioned in his advisory, corn earworm moth captures in our network of black light traps are beginning to increase. Reports north of the James River ranged from 0 (Essex Co.) to 7 (Richmond Co./Warsaw) moths per night. In southeast Virginia, reports ranged from <2 (Petersburg) to 10 per night (Southampton Co./Courtland). Please see the attached table (pdf) for more information. Additional information: blacklight-table-10-pdf
New invasive insect pest of soybean
I am paraphrasing an email we received from Jack Bacheler at NC State last week alerting us to a new invasive insect pest of soybeans. The Figure images (Fig. 1, Fig. 2, and Fig. 3) are attached:
The bean plataspid, Megacopta cribraria Fabricius, is a new invasive pest from south Asia that is currently spreading throughout the southeastern United States (Fig. 1). This insect is a piercing sucking pest (similar feeding as stink bugs) on legumes and was first found on kudzu in Georgia during December 2009. It has since been confirmed on both soybeans and kudzu in both Georgia and SoI am paraphrasing an email we received from Jack Bacheler last week alerting us to a new invasive insect pest of soybeans. The Figure images (Fig. 1, Fig. 2, and Fig. 3) are attached: uth Carolina in 2010. The confirmed distribution is represented in Fig. 2.
Research on insecticide management options is being conducted by Dr. Phillip Roberts, University of Georgia, and his colleagues. The University of Georgia researchers and Dr. Jeremy Greene, Clemson University, are monitoring this pest and we need to be vigilant for the appearance of this pest in North Carolina. Many invasive insects are found in extremely high numbers upon initial establishment, which may aid in our detection of this pest (Fig. 3). Current numbers from Georgia in soybeans are reported as close to 10 insects per sweep near field borders, where the distribution of this pest is the highest.
Please contact me if you see this insect in your soybean field (Ames Herbert, 757-657-6450, ext 411, Herbert@vt.edu).
Additional information: bean-plataspid-jul-22-2010-ppt
Corn earworms are increasing and many appear resistant to pyrethroids
Corn earworm is on the rise. Trap catches started increasing this week, up from near zero last week, and we are seeing moths flying in soybean, peanut and cotton fields. The worst news on corn earworm relates to the resistance monitoring program. As in the past several years, we are testing live-caught male moths in what we call the AVT program (adult vial test). Live moths are placed individually into small glass vials pretreated with a known amount of cypermethrin (the pyrethroid used throughout the south in the AVT program). We check the vials in 24 hours and any live moths are considered to be ‘survivors’ demonstrating resistance. Although we have only tested 363 moths to date, we found that 48% survived in this week’s sample (see the attached chart). This is the highest level ever recorded in Virginia. Last year we found about 40% survivorship in some later season samples, which was the highest level for the years up to 2009. We will continue posting the AVT results, but all indications are that we may be in for some pyrethroid control issues again this summer. Additional information: cew-avt-jul-22-2010-ppt
Cotton insect update: stink bugs low, bollworm increasing
So far we are not seeing much boll damage from stinkbugs. We think this is due to the overall very hot, dry weather we are experiencing. Week before last I saw 106 degrees on a local bank billboard in my hometown (Franklin, VA), the first time ever according to the ‘old-timers’. This week Johnny Parker with Commonwealth Gin reported that he looked at a couple of thousand acres and found only about 3 bolls total with stink bug damage. He says he has never seen stink bug pressure this low. Yesterday he found a hot spot in an irrigated field approaching 10% boll damage with about 15% dirty blooms. The only insect in the field was tarnished plant bug so he assumed they had caused the boll damage (spots with light internal damage).
Corn earworm/bollworm is on the rise. Trap catches started increasing this week, up from near zero last week, and we are seeing moths flying in soybean, peanut and cotton fields. Stan Winslow with Tidewater Agronomic, Inc. in North Carolina reported today that they were finding an increasing number of bollworm eggs in cotton. We are recommending that growers not react to eggs, but wait to see how they progress and base any sprays on worm escapes. If worm pressure gets high, we can expect some escapes. For example, last year we found 2-4% boll damage on some Bollgard 2 and Widestrike varieties. But time will tell. We may or may not have to treat depending on how many worms break through the Bt and Widestrike toxins.
Insect trap counts on the Eastern Shore for Week Ending July 16
Blacklight trap catch in Painter this week again yielded very little activty from the major moth pest species. Weekly counts were as follows: 0 European corn borer, 0 armyworm moths, 2 corn earworm, 6 hornworm moths (increasing), 42 green stink bugs (increasing), 3 brown stink bugs (decreasing). We are still not seeing the main flight of corn earworm. Spider mites remain an important pest concern particularly in areas that have missed the rain, or commercial tomatoes. An outbreak of fall armyworm in late-planted corn was also reported this week. Coragen insecticide is a new option for fall armyworm control in early whorl stage corn. It has shown very good efficacy, with a long residual, and it is a safe chemical to apply.
Corn earworm black light trap captures for the week ending 15 July 2010
New supplemental label for Belay applied aerially on soybeans, cotton, and potatoes
Attached is a Belay Supplemental label that has been approved by the EPA and is pending state approval. This Supplemental Label allows Belay to be applied aerially in soybeans, cotton, and potatoes. In addition, the aerial use rate is 3 to 6 fl oz/A. This is a higher use rate than the current ground application label (3 to 4 fl oz/A); however, the EPA has approved the change of the use rate for Belay when applied by ground in soybeans and cotton. That Supplemental Label will be out this coming week. Additional information: belaysuppl-label-aerialappl-2010-bel-0015-xcaflny-pdf
Insect pest activity on the Eastern Shore for week ending July 8
Blacklight trap catch in Painter has revelealed very little insect activty this week. We are still not seeing the main flight of corn earworm, which is good news for our growers because we they’ve had enough to worry about with drought. The hot dry weather has caused some outbreaks of Spider mites in tomatoes and soybeans. Commercial tomato growers are having particular difficulties managing this pest even with some of the best miticide tools on the market for vegetables (Oberon, Portal, Acramite, and Agrimek). I’ve heard of some tomato fields receiving applications of all of these products on a 5 day rotation and they still have spider mites, particularly in the lower canopy. Some rain could really help.