INSECT MONITORING PROGRAM – 2023

We are monitoring for corn earworm in multiple Virginia locations this year using the Heliothis (mesh) trap baited with the Hercon pheromone lure.  These moths can damage numerous crops including sweet corn, tomatoes, cotton, soybeans and green beans. Traps of 7 or more moths per week indicate the need for intensive scouting of crops for the pest.

Thank you to all of our trap monitors. 

Northampton County and Eastern Shore AREC – Led by Helene Doughty, Research Specialist Sr. | Entomology, Eastern Shore Agricultural Research and Extension Center

Bill Tiver monitoring in Clover, VA (Halifax County)

Brian Currin (Montgomery County, VA)

Week July 20^th – July 27^th 2023   Helitothis traps have been set up in 4 locations in Northampton County as well as one location each in Accomack County, Montgomery County, and Halifax County to monitor the activity of the corn earworm moths.  Pheromone bucket traps have also been set up in Northhampton County to monitor the flight activity of the fall armyworm. 

Fall armyworm trap catch has been low so far, although it’s a little early for that tropical moth. 

Within the past week two outbreaks of FLS (frogeye leaf spot) have been reported in southeastern Virginia. Southeastern Virginia has experienced warm, humid conditions and frequent rain events which favor FLS development. Both outbreaks were found on soybean varieties susceptible to FLS in the R1 stage. This creates an issue as the recommendation for fungicide timing on soybeans is R3-R5. Having disease already in the field is also less than ideal as fungicides perform better if applied prior to symptom development. To deal with this situation I recommend:

Scout fields for FLS and Target…

• fields planted to FLS-susceptible varieties and with a history of frogeye leaf spot
• fields in continuous soybean production
• fields in short rotations between soybean crops
• fields with conservation tillage
• low-lying areas of fields

If you have fields that meet the above risk factors you should use a preventive fungicide application no sooner than R1. If you find FLS in R1 soybeans spray immediately with a FRAC Group 3 (DMI, triazole) fungicide as these fungicides have some curative activity. University pathologists in the U.S. have had the best results with Domark, Topguard, Lucento, Revytek, and Miravis Top when spraying after FLS is detected. Follow-up sprays may be needed if FLS continues to progress.

Written by Brian Currin (Entomology Graduate Student at Virginia Tech). Brian is working on sweet corn IPM for his research. Corn earworm monitoring is continuing in Virginia. As we grow nearer to the time corn begins to silk, and when corn earworm moths lay their eggs, monitoring is important for integrated pest management strategies.

Trap catch for this week ending July 20 at two locations was as follows:

Clover, VA (Data collected by Bill Tiver) 77 moths per wk (high pressure)
Blacksburg, VA (Data collected by Brian Currin) only 2 moths (very low pressure)

The farm in Blacksburg has yet to reach its reproductive stage but during trap monitoring more adults were seen flying in the corn.

Mid-July is that time of year when we begin to see corn earworm moth activity really pick up in Virginia.  As most of us know, corn earworm moths deposit their eggs on flowering plants of many important agricultural crops including sweet corn, cotton, soybean, and hemp, to name a few.  Eggs hatch in a couple days into larvae that feed on buds, flowers, fruit, and leaves.  Pheromone trap counts of 7 or more CEW moths per week indicates that this pest is active on the farm and could potentially become a pest threat.   

Trap catch for this week ending July 14 at several locations is as follows:

In summary, CEW moth activity has subsided on the Eastern Shore for the time being as the pest is likely mostly in the larval stage right now.  In Chatham (southside VA) CEW moth activity has remained high >50 moths per week.  Blacksburg, VA has experienced only low moth numbers so far. 

Thank you to Helene Doughty who is monitoring the traps on the Eastern Shore, Bill Tiver who is monitoring a trap in Clover, VA, and Brian Currin who is monitoring traps around Blacksburg.

This article was written by Jordan Thompson, a graduate student in the Department of Entomology working with Drs. Tom Kuhar and Alejandro Del Pozo. Jordan is a graduate student at Virginia Tech studying the Asian jumping worm in Virginia and hoping to find possible control methods. Jordant95@vt.edu

Earthworms might not be the first thing that comes to mind when thinking about invasive species. In fact, you might be familiar with all the benefits of earthworms, such as how they recycle nutrients by breaking down organic matter, making them more available to plants, or how they tunnel through the soil, aerating it, which in turn makes room for delicate plant roots to spread. You may have even purchased a bag of worm castings to spread in your garden, or perhaps you compost with red wigglers. Whatever your association with earthworms, the thought of eradicating them probably didn’t immediately come to mind.

Unfortunately, we now have a worm in the United States that is detrimental to our delicate soil ecosystems. Known as the Asian jumping worm (Amynthas spp.), this invasive earthworm is named for its signature jumping move, a form of predator evasion. They are characterized by their smooth iridescent skin, and their pale clitellum (band). The Asian jumping worm is able to quickly reshape invaded soil ecosystems, resulting in soil that offers minimal benefits to plants and other terrestrial organisms. Where there was once a rich organic matter layer, is now a dusty and lifeless earth, incapable of supporting certain plant life, thereby permanently altering the landscape and inviting other invasive species to move in and thrive. It is evident that these worms are far from being the allies we seek in maintaining a healthy ecosystem.

But how did they get here? Why does it do so well in so many diverse soils? What are the long-term effects of this species? Let’s break it down.

The Asian Jumping Worm: An Uninvited Guest

The Asian jumping worm originally hails from East Asia and is believed to have been introduced to other regions through various pathways, including horticultural trade, transportation of plants, and contaminated soil or plant material. One key factor contributing to the Asian jumping worm’s rapid spread is its ability to reproduce via parthenogenesis, meaning it can reproduce without a mate. Each worm produces tiny cocoons at around 60 days of age, and each cocoon will hold between 2 and 20 worms – which will again start producing more cocoons in about 60 days. This allows for about 2 generations per year. Often in a soil rich in organic matter, it is not unusual to find hundreds of worms living within an area of a few square feet. The juveniles are almost microscopic, resembling tiny white threads. The cocoons are the size of a mustard seed, and could easily be picked up by animals and humans walking through worm infested soil.

Additionally, the Asian jumping worm’s adaptability to different soil types is another reason for its success as an invasive species. Although it seems to prefer organic matter rich soils, it can thrive in a wide range of soil conditions, even in sandy or clayey soils. Moreover, unlike other earthworms which tend to stay within certain soil layers, Asian jumping worms are more surface-dwelling, making them highly mobile and able to colonize new areas rapidly.

Their ability to survive in colder climates also contributes to their successful spread. Adults will die with the first frost, but leave behind specialized cocoons that protect their eggs and developing juveniles during winter months. This enables them to establish populations in regions that experience cold winters.

In 2022, Asian jumping worms had been confirmed in a handful of counties in Virginia, but a bit of citizen science with the help of Facebook confirms their presence is being severely under-reported or simply, they’ve been surviving unnoticed, and have likely spread well beyond the original counties.

Disturbing the Ground: Impacts on Soil Ecosystems

Asian jumping worms have a voracious appetite for organic matter. They consume leaf litter, mulch, and other organic debris at an accelerated rate, rapidly depleting the available organic material in the soil. This feeding behavior disrupts the soil structure and leaves soil vulnerable to runoff, in addition to reducing the plant life capable of growing there. This specifically affects forest understories, where small trees and shrubs are essential in providing groundcover, soil stability, and forage for wildlife. When Asian jumping worms invade, it can alter the understory therefore altering the native habitat and displacing wildlife and native plant communities.

In residential areas, avid backyard vegetable growers might notice their gardens becoming less prolific. Their plants might begin to struggle and eventually they may see bare spots where once there were lush gardens. Compost piles can become breeding grounds as banana peels and grass clippings become fuel for more generations of jumping worms. In large turf areas such as golf courses, where worm castings already present an issue with aesthetics and maintenance, worms that altogether destroy the soil could spell disaster for ranges trying to maintain quality greens.

There is some understanding of how these worms alter soil chemistry, C/N (carbon to nitrogen) ratios, and soil electrical conductivity, but more research is needed to better understand the severity of these alterations and their long term effects. What we do know is that while soil development takes thousands of years, the Asian jumping worm can significantly alter soil composition in a matter of months. This poses a grave concern and demands our immediate attention.

Current Research and Areas of Study

Researchers from Virginia Tech’s Department of Entomology are actively studying the impacts of the Asian jumping worm in Virginia and exploring potential control methods. Through field observations and laboratory experiments, they are investigating the effects of Asian jumping worms on other soil arthropods, soil nutrient availability, soil electrical conductivity, and more. By understanding the mechanisms through which these worms degrade the soil, researchers aim to develop targeted management strategies. These may include exploring biological control agents, evaluating cultural practices, and assessing the efficacy of chemical interventions.

Current Research and Areas of Study

Researchers from Virginia Tech’s Department of Entomology are actively studying the impacts of the Asian jumping worm in Virginia and exploring potential control methods. Through field observations and laboratory experiments, they are investigating the effects of Asian jumping worms on other soil arthropods, soil nutrient availability, soil electrical conductivity, and more. By understanding the mechanisms through which these worms degrade the soil, researchers aim to develop targeted management strategies. These may include exploring biological control agents, evaluating cultural practices, and assessing the efficacy of chemical interventions.

When I look at how small my peanuts are today, spraying them for leaf spot seems hard to imagine.  We’re at least 40% behind in peanut heat units compared to previous years.  Slow, late development tells me we will likely be digging peanuts later than usual.  How does that affect initial fungicide spray program decisions?

To me, digging later means there’s potential to apply more fungicide sprays, which can get expensive.  My response to late-developing peanuts is to delay the first leaf spot application.  The rule of thumb NC and VA have used for initiating leaf spot fungicide programs is 60 DAP (days after planting), but no later than July 10^th.  But with peanuts so far behind I’d consider shifting that back to no sooner than July 15^th, maybe a little later to extend disease control later in this season and to avoid “extra” leaf spot sprays.  Not only for leaf spot, but also for soilborne diseases like SSR (southern stem rot/white mold) and SB (Sclerotinia blight).  This may be especially true for SB as temperatures cool down as we approach harvest and cool temps favor SB.  Saving expensive SB fungicide applications in lieu of a later harvest makes sense to me.  I recommend keeping up with peanut heat units and the leaf spot and SB advisories on the Peanut Cotton InfoNet (url link here) or call the Peanut Hotline at 1-800-795-0700.  That way you can gage peanut maturity and disease risk to help make fungicide timing decisions. 

If questions arise concerning peanut disease management this season please don’t hesitate to reach out to me. My contact info is below:

address: 6321 Holland Rd., Suffolk, VA 23437 office phone: (757) 807-6536; mobile phone (preferred): (757) 870-8498 email: dblangston@vt.edu

We know that we aren’t the only ones, but we are monitoring corn earworm moths again in Virginia at multiple locations. Pheromone trap counts of 7 or more moths per week indicates that this pest is active on the farm and could potentially become a pest threat to the numerous crops that it attacks such as sweet corn, cotton, hemp, soybean, tomato, and many others. Female egg-laying moths are particularly attracted to flowering plants or plants with fruiting stages.

Trap catch for this week ending June 29 at several locations is as follows:

• Townsend (Eastern Shore) – 4 moths
• Cheriton (Eastern Shore) – 0
• Machipongo (Eastern Shore) – 0
• Nassawadox (Eastern Shore) – 0
• Clover (Southside VA) – 66 moths
• Blacksburg (southwest ridge and valley) – 2 moths

Thank you to Helene Doughty who is monitoring the traps on the Eastern Shore, Bill Tiver who is monitoring a trap in Clover, VA, and Brian Currin who is monitoring traps around Blacksburg. Moth catch was low on the Eastern Shore and in Blacksburg this week, but rather high at the Clover site; however, sweet corn is in reproductive stages on that farm and probably a very attractive location in southside, VA.

I’ve been getting questions about peanut in-furrow fungicides and nematicides lately. The primary question is what to use in-furrow since Proline availability is limited, but should be available for later plantings.

Let’s start with why in-furrow Proline was initially recommended for peanuts. In-furrow applications of Proline were found to reduce losses to CBR (Cylindrocladium black rot ) in the early 2000’s by Dr. Pat Phipps. While not as effective as the fumigant Vapam, growers used it because it was less expensive and much easier to apply than Vapam. This caused widespread use of Proline in-furrow in Virginia and North Carolina and became a standard practice to reduce losses to CBR. The early trials evaluating Proline in-furrow did not demonstrate activity on any other peanut disease in Virginia. Thus, Proline in-furrow was used specifically to reduce losses to CBR.

Fast forward to 2023. Due to past and continued breeding efforts towards CBR resistance in Virginia-type peanuts coupled with longer peanut rotations, CBR has become a disease of the past. We have not observed a single peanut sample in the Tidewater AREC Plant Diagnostic Lab where CBR was confirmed as causing disease on peanut since I started here back in 2014. I have not heard anyone mention problems with CBR in Virginia or North Carolina nor have I seen it in my peanut trials or grower fields. So why are some growers still using Proline in-furrow, especially since the disease it was meant to control is not a problem. Good question! I have not used Proline or any other in-furrow fungicide in my peanut trials for years with no issues.

So what’s the bottom line? To me, Proline in-furrow is an added expense that doesn’t provide measurable disease control in our area unless you’re growing Valencia peanuts or another type besides Virginia-type peanuts. Also, there is no replacement product currently labeled for peanut except Propulse which contains the active ingredients in Proline and Velum. I have had someone ask about using Provost Silver as an in-furrow replacement for Proline because it contains the active ingredient in Proline (prothioconazole), but Provost Silver is not labeled for use in-furrow and the tebuconazole component will cause delayed emergence and growth in seedling peanuts. What about Velum? Velum in-furrow is labeled for Aspergillus crown rot, early season leaf spot, early season southern stem rot (white mold), and nematodes. In Virginia, the utility of Velum in-furrow is primary against nematodes. In my opinion, the “must have” in-furrow products on peanuts across the board should be inoculants and thrips control insecticides. I don’t see dropping Proline in-furrow on peanuts causing any disease issues.

If you have questions about in-furrow fungicides in peanuts, please feel free to contact me by e-mail (dblangston@vt.edu) or by phone: office (757) 807-6536; cell (757) 870-8498. If you want to drop in, my address is 6321 Holland Rd., Suffolk, VA 23437.