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).

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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