Remember soybean aphids? They might be in your fields

By:  Andy Michel and Kelley Tilmon

Note for Paulding County growers:  If you suspect soybean aphids in your field, please call ANR Educator Sarah Noggle at 419-399-8225 with field location and soybean variety to have your field scouted and aphid sample taken for research purposes.

Soybean aphids have always been around Ohio, but it has been a while since we have had many fields with high populations.  Based on recent scouting, we have noticed increasing populations of soybean aphids.  As we go into the critical growth stage of soybean, this is also the most important time to check your fields for soybean aphids and see if you have exceeded the threshold of an increasing population of 250 aphids per plant.

To scout for soybean aphids, walk at least 100 ft from the field edge and count the number of aphids from 5 plants in 10 different locations.  If your average is greater than 250 per plant, you’ll need to come back and re-scout 3-4 days later.  If the aphid population increased in that time, an insecticide application is recommended.  Keep in mind that to accurately determine the threshold, scouting should be performed at least weekly and multiple times a week if aphids are active in fields.

Soybean aphids can cause yield loss up to the late R5 to early R6 growth stage. If an application is necessary, there are several effective insecticides available.  Although some soybean aphid populations in the western corn belt are resistant to pyrethroids, we have not seen any evidence of this in Ohio.  If you make a pyrethroid application and suspect resistance, contact us, Andy Michel or Kelley Tilmon (michel.70@osu.edutilmon.1@osu.edu) or your local extension educator.

Check out the new Michigan State/Ohio State Field Crops Insect Pest Management Guide

Press Release from Chris DiFonzo (Michigan State) and Kelley Tilmon (Ohio State)

The newly completed Michigan State/Ohio State Field Crops Insect Pest Management Guide is available for online use and downloads at https://aginsects.osu.edu/sites/aginsects/files/imce/MSU%20-%20OSU%20Insect%20IPM%20Guide.pdf

This publication contains a series of chapters with information on biology, damage, management recommendations, and insecticides related to insect pests in field crops in Michigan and Ohio. Chapters cover field corn, soybean, wheat, and other small grains, alfalfa and grass forage, and (for Michigan growers) dry beans and sugar beet. Each chapter stands alone, focusing on a particular crop.

In the preparation of this guide, we checked state databases and consulted labels for each of the pesticides listed in the crop chapters; we made every effort to include correct information and to list most of the commonly-used products for Michigan and Ohio. However, labels do change over time. Always read the labels of the products you use to reconfirm application rate, precautions, PPE, pre-harvest intervals, and other key pieces of information prior to spraying.

Users are the best source of feedback on this guide. If you see information that is not correct or complete,  please contact us so that we can update the guide accordingly.

Fall armyworms are marching

Fall armyworm damage to a yard in Paulding County. If you are seeing this please contact me. There is a chance the yard will come back with the rains received on Thursday evening.

I have received many phone calls and emails this week about armyworms this week from both farmers and landowners.  I have worked with Curtis Young in Van Wert County to make the positive ID of Fall armyworm.  I have shared some of the pictures of the damage armyworms can do.  I am receiving these calls from around the county.

Fall armyworm in a lawn in Paulding County. The threshold for control is 4 worms per square foot for lawns/homeowners.

Across the US, the Fall armyworm numbers have been much higher than in previous years due to our current weather patterns and the life cycle of Armyworms, there is a chance we could see a third-generation yet this year.  These guys like to feed on the species in the grass family and their “candy” is newly seeded yards (within the last few years), volunteer wheat fields, and newly seeded forages. Additionally, I am linking extra articles with information on control and general question both agronomically and for homeowners. As always, contact me with your questions.

Thanks,

Unusual Armyworm Outbreaks are Taking Many by Surprise

Kelley Tilmon, Mark Sulc, Andy Michel, James Morris

Figure 1. Fall armyworm feeding damage. Photo by James Morris, OSU Extension

We have received an unusual number of reports about fall armyworm outbreaks particularly in forage including alfalfa and sorghum-sudangrass, and in turf.  Certain hard-hit fields have been all but stripped bare (Figure 1).  Armyworm is not typically a problem in Ohio in late summer, so we encourage farmers to be aware of feeding damage in their fields.  Armyworms are much easier to kill when they are smaller, and feeding accelerates rapidly as they grow, so early detection is important.  Look for egg masses glued not only to vegetation but to structures like fence posts.  Egg masses have a fluffy-looking cover (Figure 2).  When the cover is peeled back, eggs are pearly and tan when new, and turn darker as they approach egg-hatch.

Figure 2. Fall armyworm egg mass, with cover peeled back. Photo by Ric Bessin, University of Kentucky.

Fall armyworm caterpillars vary in color from greenish to tan to dark brown with stripes along the body.  They can be easily confused with other species, but a good identifier is an inverted white “Y” shape behind the head. (Figure 3). Another species, true armyworm, feeds at night but fall armyworm will feed during the day.

Insecticides will not penetrate egg masses well; it’s best to spray caterpillars when they are less than ¾ inches long, at which point most armyworm-labeled pyrethroids will kill them reasonably well.  For larger caterpillars, products containing chlorantraniliprole will provide longer residual which may help with control of the harder-to-kill caterpillars over ¾ inches.

Figure 3. Fall armyworm caterpillar, with an inverted “Y” near the head. Photo by James Morris, OSU Extension

In forages, a threshold that can be used is 2-3 fall armyworm larvae per sq foot.  If larvae are smaller (less than ¾ inch), they can still do a lot of feeding and are worth treating with an insecticide application. An early cut can help limit damage, but check the field for survivors.  If survivors are abundant, an insecticide application may be warranted to protect nearby fields.  Armyworms get their name from moving in large bodies (marching) to new feeding areas.

In corn, armyworms can randomly feed on leaves, with holes occurring throughout the leaf surface. The more damaging stage is when they feed on developing silks and kernels after entering the ear. Once they enter the ear, control by insecticides is much more difficult.  Most Bt corn varieties with above-ground protection is labeled for armyworm control, but resistance to several Bt traits has appeared in the US.  While we have not found Bt resistance in armyworms in Ohio, we would recommend growers scout ALL corn (Bt or non-Bt) for any evidence of damage or resistance. If feeding is found, please contact us (tilmon.1@osu.edu, or michel.70@osu.edu) or your local extension educator.

Figure 4. Fly Free Dates in Ohio. Wheat planted after this date have lower risks of damage from Hessian Fly as well as other pests, including fall armyworm and aphids that spread wheat viruses

Fall armyworm does not overwinter in Ohio.  Moths come up from the South early in the season and temporarily colonize the area, especially in grassy areas.  The current caterpillars are second-generation.  If we have a warm fall we could possibly see a problem third generation, especially in forage, cover crops, and winter wheat planted before the fly-free date (see Figure 4).

Please visit the Forages chapter in the Michigan State/Ohio State Field Crops Insect Pest Management Guide for management notes and labeled insecticides in forages.  https://aginsects.osu.edu/sites/aginsects/files/imce/MSU%20-%20OSU%20Insect%20IPM%20Guide.pdf

 

 

 

 

 

Alfalfa Weevil Infestations Becoming Severe in Some Fields

GDD

Figure 1: Accumulated growing degree days (base 48°F sine calculation method) for January 1- May 2, 2021, at several CFAES Ag Weather System (https://www.oardc.ohio-state.edu/weather1/) locations and additional NOAA stations around Ohio (data courtesy of the Midwestern Regional Climate Center (https://mrcc.illinois.edu).

By Mark SulcAaron WilsonKelley TilmonGreg LaBarge, CPAg/CCACurtis Young, CCAAndy MichelBeth Scheckelhoff

Alfalfa fields across Ohio have been observed with alfalfa weevil infestations, some with high numbers and severe feeding damage to the alfalfa.

Accumulation of heat units (growing degree days or GDDs) for alfalfa weevil growth have progressed across Ohio and are now in the 325 to 575 heat unit range indicative of peak larval feeding activity (Figure 1). We are about 2 weeks ahead of GDD weevil accumulation last year.

From the road, severe weevil feeding can look very much like frost injury (Figure 2). Do not be fooled, get out and scout! We have observed very minor frost injury to alfalfa from last week’s cold nights, so if you see “frost injury” in alfalfa, it is more likely to be severe alfalfa weevil feeding damage.  For more information on scouting and signs of damage, see the April 20 article in this newsletter: (https://agcrops.osu.edu/newsletter/corn-newsletter/10-2021/alfalfa-weevil-%E2%80%93-it%E2%80%99s-closer-you-think). Continue reading

Are Periodical Cicadas a Threat to Field Crops?

Are periodical cicadas a threat to field crops? The quick and dirty answer to this question is NO. Are they a threat to the health and welfare of anything? There is no quick and dirty answer to this question.

The best way to answer the second question is to start by looking at what the periodical cicada is, what it feeds on, where one would expect to find them, and its life cycle.

The periodical cicada or 17-year cicada is an insect with an extremely long life cycle that takes 17 years to get from the egg stage to the adult stage. Some people mistakenly refer to this insect as a locust. Unfortunately, locusts and cicadas are not one-in-the-same.  Locusts are a type of grasshopper (Order Orthoptera).  Cicadas (Order Hemiptera) are not grasshoppers. And the 2 look nothing like one another.

grasshopper

Grasshoppers

Dog-day cicada Continue reading

Periodical Cicadas are Poised to Emerge

Authors Joe Boggs
Periodical Cicada
Periodical Cicadas (Magicicada spp.) take either 17 or 13 years to complete their development out-of-site in the soil.  Adults emerge en masse in the spring.  The name of the genus captures the almost magical appearance of these insects:  Magi– comes from the Ancient Greek magos which means “magician.”

Continue reading

Call for Cooperators – 2021 Western Bean Cutworm Monitoring Program

Paulding County OSU Extension will be monitoring for Western Bean Cutworm (WBC) moths again during the 2021 growing season. We currently have two farmer cooperators for 2021, with the goal of having five throughout Paulding County. We are especially looking for fields near Paulding, Junction, Grover Hill, and Oakwood.

Moths are trapped by placing pheromone traps (see picture) at the edge of cornfields throughout the county and checked on a weekly basis beginning late June and proceeding through August.

The WBC monitoring program is a state-led initiative to better understand insect populations, and develop management recommendations for growers. Each week, WBC numbers will be published in the C.O.R.N. newsletter. Paulding County WBC numbers will also be published on this blog on a weekly basis.

If you are interested in hosting a trap in one of your cornfields in 2021, please call ANR Educator Sarah Noggle at 419-399-8225 by March 29.

Are Stink Bugs in Your Soybean?

As soybean begin to produce pods and seeds, it becomes a good food source for stink bugs. These insects like to feed on the developing seed, leading to wrinkled or shriveled seed.  There are many types of stink bugs, but Ohio’s most common stink bugs include the green, the brown, and the brown marmorated.  Also, stink bugs have nymphal stages that can look very different than the adults—nymphs are smaller and lack wings but feed all the same, if not more, than the adults.  To look for stinkbugs, take a set of 10 sweeps in 10 different areas of the field (although stink bugs are mostly found along the edges, they can also be found in the interior of the field).  If the average number of stink bugs is higher than 4 per set of 10 sweeps, treatment is necessary (this decreases to 2 per set of 10 sweeps if soybean is grown for seed or food grade).  Visit our website for more information on stink bugs in soybean, including helpful guides for identification (aginsects.osu.edu).

Past WBC Peak Flight, Low Numbers Across State

Western bean cutworm (WBC) trap counts for the week of August 10 – 16 decreased over the past week putting all monitoring counties below the scouting threshold. The low numbers indicate we are officially past peak flights.  Overall, a total of 27 counties monitored 90 traps, resulting in 38 WBC adults (a statewide average of 0.4 moths per trap) (Figure 1).

A picture containing text

Description automatically generated

Figure 1. Average Western bean cutworm adult per trap followed by the total number of traps in the county in parentheses for the week ending August 16, 2020.

Asian Longhorned Tick; a New Tick Known to Attack Animals in Large Numbers!

By:  Tim McDermott DVM, OSU Extension Educator, Franklin County (originally published in Farm and Dairy)

The Asian long-horned tick attacks wild and domestic animals and humans. Photo by Anna Pasternak, a UK entomology graduate student.

My colleague Erika Lyon wrote a great article on the January 24th, 2019 All About Grazing column in Farm and Dairy (link) that discussed the invasive Asian long-horned Tick. I want to give an update on where that tick is now, where its new host range is located, and what potential disease problems to look out for.

The Asian long-horned tick is native to East Asia as well as Australia and New Zealand.  It had not previously been found in the United States prior to its discovery on a farm in New Jersey in the fall of 2017.  This tick is a major concern as it reproduces via parthenogenesis, which means that the female does not need a male in order to reproduce, she can start laying eggs, which are genetic clones, that can overwhelm the host in very large numbers. It has been found on humans, companion animals including cats, dogs and horses, livestock species including chickens, cattle, sheep and goats and multiple other mammals and birds including foxes, bears, geese, deer, raccoons, skunks, hawks, groundhogs and opossum (which are known to consume ticks as food). Continue reading

WBC Numbers Continue to Decrease

Figure 1. Average Western bean cutworm adult per trap followed by the total number of traps in the county in parentheses for the week ending August 9, 2020.

Western bean cutworm (WBC) trap counts for the week of August 3 – August 9 continue to decrease in the majority of monitoring counties. Trap counts indicated only one county, Lake, had an average of 7 or more moths, suggesting scouting is necessary. Overall, a total of 26 counties monitored 89 traps, resulting in 111 WBC adults (a statewide average of 1.2 moths per trap) (Figure 1). Monitoring for WBC moths will continue in many counties until the end of August.  

 

Leafhoppers, Grasshoppers, and Beetles, Oh My!

Adult red-headed flea beetle (P. Beauzay, NDSU)

By Kelley Tilmon, Andy Michel

As the summer progresses we are receiving reports of insect problems often encouraged by hot, dry weather.  Last week we reported on spider mites and especially if you are in an area of continued dry weather we recommend scouting your soybeans and corn  https://agcrops.osu.edu/newsletter/corn-newsletter/2020-22/watch-spider-mites-dry-areas .

Some areas are also reporting increases in young grasshoppers in soybeans, another insect favored by dry weather.  Grasshoppers of often start on field edges so early scouting may allow for edge treatment.  Japanese beetles are another common defoliator of soybean that are starting to appear.  Both of these pests fall into a general defoliation measurement, and we recommend treatment if defoliation is approaching 20% on the majority of plants in post-flowering beans.  Download our guide to estimating defoliation in soybean at https://aginsects.osu.edu/sites/aginsects/files/imce/Leaf%20Defoliators%20PDF_0.pdf Continue reading

True Armyworm Infestations

By:  Andy Michel, Curtis Young, CCA, Kelley Tilmon

We received many reports of true armyworm infestations in wheat, barley, and corn. These are black or green caterpillars with stripes along the side and orange heads.  In the spring, true armyworm moths migrate from the south and lay eggs in grasses such as forage and weed grasses, winter wheat and barley, and rye cover crops.  When the eggs hatch, the larvae can significantly damage wheat and barley before then moving to young corn. Usually, moth flights occur in April, but we may have had a second peak the first or second week of May—it’s likely the caterpillars feeding now are from this later flight. Right now, wheat, barley, and corn should be inspected for true armyworm populations. Armyworms like to hide during the day and feed at night, so scouting should occur at dusk or dawn, and/or on cloudy days. Continue reading