Peanut Burrower Bugs (Pangaeus bilineatus) have been collected and identified, by the Virginia Tech Insect Identification Laboratory, on the Tidewater AREC farm. Peanut burrower bugs are a subterranean pests that feed on pods and pegs of developing peanuts. Burrower bugs have most likely been around for a while but Lorsban (active ingredient is chlorpyrifos) was controlling their populations. Since the removal of Lorsban (chlorpyrifos) from market shelves, there are no effective chemical controls for producers. Damage caused by the peanut burrower bugs looks similar to stink bug damage. This damage is only seen when peanuts are shelled. The skin is removed at buying points by graders: The insect does not leave an indicator of damage on the shell of the peanut. Peanut burrower bug is more of an issue in hot dry years, and they are just as sporadic as southern corn rootworm.
In terms of prevention, there is no chemical control with the loss of lorsban. Some producers have gone back to using a moldboard plow and completely turning over the soil. Some producers have been planting earlier hoping for a thicker hull development earlier in the season. Damage is minimal in Suffolk, VA, but it is something to keep in mind.
Black light trap captures for corn earworm moths averaged 15 per night in Greensville and 10 per night in Suffolk this week. Here is the Table. Our adult corn earworm cypermethrin vial tests are at 20% survival for the 5 microgram/vial rate of this pyrethroid insecticide (n = 754 moths tested, Suffolk, VA). I’m sweep netting high numbers of corn earworm larvae in R5 soybean at our research center, along with an increasing soybean looper population.
We continue to monitor corn earworm, fall armyworm, and beet armyworm at several locations around Virginia. On the Eastern Shore, Helene Doughty observed the following this week: Very low (less than 4 moths per week at several of the Northampton County locations, but 34 CEW moths caught in Painter, VA in Accomack County. Fall armyworm activity has been low throughout Virginia, but Helene did pick up on increased numbers (13 moths) in a bucket trap in Townsend, VA. which is the highest so far this year, but still relatively low. In addition, Helene is monitoring for beet armyworm moth, which can deposit eggs on many different crops from soybeans, cotton, and vegetables like tomatoes, peppers, beans, beets, and spinach. There were high numbers of BAW moths (218) caught in Painter, VA this week. So be on the lookout for this pest. I’ve noticed over the years that they will often attack pigweed and lambsquarters weeds before infesting cash crops.
In Clover, VA (Halifax County), Mr. Bill Tiver has been monitoring for CEW moths all summer in his commercial sweet corn and has experienced relatively high catch most of the summer. This week he caught 174 CEW moths coming off of 228 moths last week. These are high numbers and has resulted in high CEW pest pressure. He told me that he has sprayed his sweet corn every 3 days, but has still suffered about 15% ears infested with CEW larvae. We don’t have all the information nailed down for thresholds yet, but moth catch over 100 probably suggests that your spray interval should be reduced to every two days. I know, easier said than done, but we can definitely reach heavy CEW flights, which command frequent controls, especially on non-Bt sweet corn.
In Blacksburg, we have not caught very many CEW moths in our sweet corn (< 5 moths per week), but several harvests of our plots this week yielded about 60-75% ears infested in our untreated control plots, despite low CEW moth trap catch. So, it is hard to figure out what trap catch really means.
By: Taylore Sydnor (graduate student), Tom Kuhar, and Alejandro Del Pozo (Department of Entomology, Virginia Tech)
The European pepper moth, Duponchelia fovealis, is native to southern Europe and became established on the west coast of the U.S. in 2010. Since, it has been reported in at least 15 states, including as a greenhouse ornamental pest in Virginia a few years ago. We’ve not heard much more about this invasive species until this summer when numerous pepper plants grown at Virginia Tech’s Homefield Farm in Whitethorne, VA began dying from girdling at the base of stems. The plants were mature and full of developing pepper fruit, which made it very frustrating.
With the help of several folks on the ORNAENT Digest Listserv, the problem was diagnosed. A European pepper moth pupa was found in one of the plants. Dr. Alejandro Del Pozo from the Virginia Tech Hampton Roads AREC has been monitoring for this pest in nurseries in eastern Virginia and shared some pheromone lures. This week we captured some EPM moths on delta traps placed in the pepper field at Homefield.
Although we have not 100% confirmed the identity of the moths, but they appear to look exactly like what has been described in the literature – based on size and color patterns; and given that that these moths oriented right to the lure septa containing the sex pheromone of EPM, I’m pretty sure that we have this species attacking peppers in Virginia, especially given the distinct conspicuous girdling damage that we observed. This seems to be pretty indicative of EPM.
What do we know about this pest?
It is a significant pest of ornamental plants and pepper crops. The larvae cause chewing damage to the stems, roots, flowers, and base leaves of crops. The damage appears as crescent-shaped holes on the outer edge of the foliage. The holes left by the larvae can facilitate fungal infection. They produce silk and can be found on the underside of leaves and on the soil surface by the main stem of the plant. We observed mostly stem girdling damage, which ultimately killed many plants. The European pepper moth larvae can be hard to detect due to small size. Large numbers of this insect can cause significant damage to the crop. It can easily spread through the movement of cut foliage and potted plants. The adult European pepper moth is small (~9-12 mm long) and is brown in color with two distinctive gold bands on the forewings. A female adult moth can lay up to 200 eggs and are white/green in color. A number of insecticides have been shown to provide effective control including diamides, spinosad, pyrethroids, acephate, and Bt among others. Insecticides should target early instar larvae before feeding. Monitoring for the moth with pheromone lures and delta traps was effective for detecting this invasive pest species.
Crawlers are the most vulnerable stage to control the Japanese maple scale under nursery conditions. Monitoring crawler activity throughout the growing season will aid to refine the timing of deployment of any control tactic.
Graduate student Mollie Wyatt (Virginia Tech, Entomology Department) took the lead on creating a video showing us the step-by-step process on how to do the ‘tape method’ for monitoring crawler activity for this pest in ornamental trees.
You can click on the link below to access to a short version of this video. You might need an actual computer to watch that clip. The full version will be posted soon on our VCE website. Stay tune! Funding to support this project was provided by the Southern IPM Center and USDA NIFA.
With current rainfall from Idalia and cooler temperatures over the next three days, peanut fields with a history of SB (Sclerotinia blight) should be sprayed soon with a fungicide that can reduce losses to that disease.
SB is favored by rainfall and periods of high relative humidity, but what really triggers it is cooler temperatures. The current forecast is for daily highs to be in the upper 70s and 55 to 60° lows over the next three days. Those lows will really get SB cranked up! I have already seen SB slowly moving in my trials and I’ve heard reports that peanut growers are seeing it in some of their fields. According to Dr. David Jordan, peanuts are likely 1 week behind in maturity compared to last year due to the record cool temperatures observed in May, so there’s plenty of time for SB to do some damage.
This late in the game the second spray of Miravis tank-mixed with Elatus surely has been applied, or is about to based on when the first spray was applied. I do not recommend the first application of the Miravis/Elatus tank-mix be used this late, mainly due to it’s having no curative activity on either LLS (late leaf spot) or SB and for reducing risk of fungicide resistance to those chemistries. I’m quite hesitant even to recommend the second application at this time.
The safe bet is applying Omega 500 for SB tank-mixed with an effective fungicide for LLS. If you sprayed Miravis/Elatus the first week of August, I’d prefer to use Omega 500 at 1.0 pt/acre in the next few days to protect against SB. If you have a field that’s notorious for severe losses to SB, you can go to 1.5 pt/acre, but I haven’t seen a big difference in control between the two rates. I consider Omega 500 to have 3 weeks of activity against SB. So if it’s been 3 weeks or more since you applied Omega 500, I’d be thinking about that 2nd application right about now. Remember, Omega 500 has a 30 day PHI (preharvest interval). That’s 30 days prior to harvesting with a peanut picker, not 30 days until digging.
One saving grace is that temperatures go up again next Monday and maintain daily lows in the upper 60s/low 70s and highs in the upper 80s/low 90s until about September 11th according to the current forecast. Most peanuts in the region have fairly dense canopies now, so while the higher temperatures may slow SB development, the disease will continue to progress and potentially explode again if favorable conditions present themselves.
Black light trap captures of corn earworm moths decreased this week in southeast Virginia. Sara Rutherford in Greensville had 13 per night; Scott Reiter reported 7 per night (Prince George-Templeton) and 8 per night (Prince George-Disputanta); Suffolk dropped to 20 per night. Here is the Table. Scott was getting 2 to 8 larvae (mostly in the 0.5-inch size range, or 4th instar) in his soybean samples this week. I had larval numbers range from 1 to 10 larvae per 25 sweeps in untreated Suffolk and Greensville soybean. There is no substitute for scouting your fields. To calculate your thresholds, please see this online calculator
Black light trap captures of corn earworm moths increased this week. Sara Rutherford reported an average of 27 moths per night for Greensville; in Prince George, Scott Reiter had 13 per night (Templeton) and 18 per night (Disputanta); in Suffolk, we saw an average of 62 per night. Here is the updated Table
In our August corn earworm vial tests, 19% of moths survived the 24-hour exposure to 5 micrograms of cypermethrin. This is below our 10-year average of 32% survival.
There are several corn earworm pheromone traps being monitored around Virginia. Many of the Eastern Shore locations have reported relatively low numbers this week, except for one humongous exception, the Eastern Shore AREC in Painter, VA, where Helene Doughty counted nearly 800 CEW moths in just two nights in one of the traps. That’s the highest density that I’ve ever seen in 20 years. It’s really quite striking because the other traps around Northampton County, VA didn’t catch very many.
In Halifax County, Virginia, Mr. Bill Tiver, is still reporting relatively high trap catch at his farm. Catch has ranged from 100 to 250 moths per week. Those numbers would likely suggest that CEW control on susceptible crops like sweet corn, tomato, and beans is a must. Sweet corn spray rotations should probably be 3 times a week under that trap catch level. Meanwhile, in Blacksburg, VA, trap catch has been relatively low so far.
Another pest of sweet corn and some other crops is fall armyworm. According to VCE agent, Stephanie Romelczyk, a sweet corn farm in the Northern Neck of Virginia had a fall armyworm outbreak in the whorls, which required a spray of Coragen. We’re all hoping that it did the trick. So in short, it’s definitely time to monitor for the “worm” pests in your late summer crops.