Holt Boyd News Column for the Week of April 20, 2025

Nebraska Extension Educator - Holt/Boyd Counties - LaDonna Werth
Nebraska Extension Educator - Holt/Boyd Counties - Amy Timmerman
Nebraska Extension Educator - Brown/Rock/Keya Paha Counties - Brittany Spieker
Nebraska Extension Educator - Holt/Boyd/Garfield/Loup/Wheeler Counties - Bethany Johnston
Nebraska 4-H Assistant - Holt/Boyd Counties - Debra Walnofer

April 26: Holt County 4-H Shooting Sports Practice; BB Gun, Air Pistol, Air Rifle, Small Bore Pistol, and .22 Rifle; 4pm, 5pm, and 6pm, Holt County Fairgrounds, Chambers, NE

April 26: 4-H Shooting Sports Leader Update Workshop, Hastings, Early bird registration (lower price in training) is April 16 https://events.unl.edu/NE4H-Shooting-Sports/ (Early Bird registration deadline is April 16, 4 pm CT. Registration fee goes up after 4pm CT on April 16 and registration will close on Friday, April 18, 4 pm CT.)

April 26-27: 4-H Shooting Sports Leader Certification Workshop, Hastings, Early bird registration (lower price in training) is April 16 https://events.unl.edu/NE4H-Shooting-Sports/ (Early Bird registration deadline is April 16, 4 pm CT. Registration fee goes up after 4pm CT on April 16 and registration will close on Friday, April 18, 4 pm CT.)

April 27: Boyd County 4-H Communications Event, 3pm, Boyd County Courthouse, Butte, NE

April 27: Holt County 4-H communications Event, 5pm, Holt County Courthouse Annex, O’Neill, NE 

April 29: Face-to-Face YQCA Training, 7pm, Holt County Courthouse Annex, O'Neill, NE https://yqcaprogram.org/

May 5: Holt County 4-H Shooting Sports Practice; BB Gun, Air Pistol, Air Rifle, Small Bore Pistol, and .22 Rifle; Holt County Fairgrounds, Chambers, NE

5. Be a good role model
   Show your child appropriate ways to deal with anger through your own behaviors. What you do may be more important than what you say.
6. Help your child calm down
   Teach your child some ways to calm down when angry. For a young child, redirect his or her attention to another activity. For older children, try having them draw or write down their feelings.
7. Set clear limits
   Let your child know what behavior is acceptable when he or she is angry and what behavior is not acceptable. You could say, “Saying you are mad or spending time alone is OK, but hitting is never OK.”
8. Focus on good behaviors
   Reward your child with attention and acknowledgement when he or she deals with anger in a positive way.
9. Use empathy
   Think about how your child may be thinking and feeling and look at the situation from your child’s point of view. If your child’s anger has to do with another person, teach empathy to your child by pointing out how the other person might be feeling. You could say something like “How would you feel if…”
10. Teach through books
    Read children’s books to your child on dealing with angry feelings. A couple of good anger books include:
    *  “When Sophie Gets Angry - Really, Really Angry” by Molly Bang
    *  “I Was So Mad” by Mercer Mayer

Source: Kim Allen, Ph.D., M.F.T., director, Center on Adolescent Sexuality, Pregnancy and Parenting, state specialist, HDFS, University of Missouri Extension & Christina Crawford, M.A., former extension associate, HDFS, University of Missouri Extension (2022)

Adapted from Connecting For Families curriculum.

Soil Temperatures Across Nebraska
Soil temperature can vary significantly depending on the time of the season, the amount of snow cover, and soil factors such as depth, moisture, type, etc. Dry, bare soils can vary as much as 10-15℉ in a single day.

During January, snow cover was absent or minimal, leading to soil temperatures at 4-inch depth dropping to 15-20℉ in most locations and 10℉ at Scottsbluff. However, these lower temperatures were not sustained for more than several days.

In February, air temperatures dropped even lower; however, soil temperatures remained relatively constant due to the significant snow cover present at that time (3-11 inches across the state).

Western Corn Rootworm
The western corn rootworm (WCR) is an important pest of continuous corn in Nebraska. Beetles can feed on corn silks and interfere with pollination, but it is the larvae feeding on corn root systems belowground that typically do the most economic damage, resulting in poor water and nutrient uptake by the plant and lodging or goose necking of plants.

Female beetles will lay their eggs in the soil of cornfields from late July through September, remaining in the egg stage for the duration of winter and then hatching as larvae in the spring. Most eggs are laid within the top 4 inches of soil, although depths up to 12 inches have been reported. Female beetles hunt for moist places to lay their eggs; under dry conditions, beetles may enter cracks in the soil to find moisture. For this reason, WCR eggs are often laid closer to the soil surface in irrigated fields compared with dryland fields.

Both temperature and moisture can influence WCR egg survival over the winter. For significant mortality to occur, chilling soil temperatures (lower than 14-19°F) must be sustained for longer than one week; the longer the duration of chilling temperatures, the greater the mortality. WCR eggs go through a mandatory period of diapause (a period of suspended development, somewhat like hibernation for an insect) during the winter. A lack of moisture during diapause can cause desiccation (drying out) and contribute to egg mortality. Studies in Nebraska have shown that reduced soil moisture (particularly a lack of precipitation during the winter) can have just as much influence on WCR egg overwintering mortality as cold temperatures during some years.

Various factors interact to affect both temperature and moisture in the field. Egg survival often increases with depth laid in the soil and level of crop residue and/or snow cover depth and snowpack duration. The latter factors act to hold moisture, insulate and moderate soil temperature. High mortality can occur when eggs are laid shallow in bare soil and subjected to dry, cold conditions.

The conditions experienced over the winter in most of Nebraska: average 4-inch depth soil temperatures mostly above 20°F should not cause extensive egg mortality. However, during the January cold snap, Scottsbluff did have a brief period with soil temps as low as 10°F. While these temperatures were not sustained for long, if combined with dry soil conditions, WCR egg mortality could have occurred.

Western Bean Cutworm
The western bean cutworm (WBC) is an important pest of corn and dry beans in Nebraska. Moths emerge in early July and lay eggs in these crops, where the larvae hatch to feed, eventually causing economic damage to the developing corn ears or bean pods.

As the caterpillars near completion of the larval stage during August to early September, they will cease feeding and leave their host plant to burrow into the soil. Once they reach a depth of approximately 4.7-10 inches (average 8.5 inches), they construct an earthen chamber cemented with their saliva and enter the prepupal stage. The depth at which WBC overwinter can be affected by soil type — sandier soils allow for deeper burrowing, with a maximum depth reported as 15.7 inches in a sandy loam soil. By overwintering deeper in the soil, WBC prepupae are more protected from cold temperature fluctuations and tillage equipment, leading to higher moth emergence the following season.

The effect of soil temperatures and soil moisture have not been as well-studied for WBC compared to WCR. However, it is known that the super-cooling point (the temperature at which the fluids inside of the insect freeze) of WBC prepupae is approximately 9.3°F. Studies show that WBC are likely not freeze-tolerant, meaning that freezing at 9.3°F will cause death. There has not been much research on the impact of chilling temperatures (temperatures that do not cause freezing but do cause cold stress) on WBC overwintering mortality.

Although more research is needed to fully understand the effects of soil temperatures on WBC mortality and how this may interact with soil moisture and soil type, the soil temperatures experienced by WBC across most of Nebraska indicate that significant mortality of overwintering prepupae is unlikely. However, the brief soil temperatures of 10°F experienced in January in Scottsbluff are likely to have increased mortality of WBC Wheat Stem Sawfly

The wheat stem sawfly is an important pest of wheat throughout much of the Central and Northern Great Plains of the U.S. The adult wasps emerge from mid-May through June and lay their eggs within the stems of developing wheat tillers. The larvae hatch within wheat tillers and feed out of sight, largely protected within the stem. Eventually, the larvae move down within the tiller and form a hibernaculum near the crown of the wheat plant. In the process of forming the hibernaculum, the sawfly larvae cut the stem, lodging the wheat to the ground. When the sawfly larvae develop their hibernaculum, they close off the cut end of the stubble and surround themselves in a transparent case.

The sawfly’s overwintering preparations make it highly resilient to cold northern winters. Typically, the sawfly hibernaculum is located in a highly protected location within the wheat stubble following wheat harvest. Prior to the onset of winter, the old crowns at the base of wheat stubble into which the sawflies are hibernating often becomes covered over by crop residue and soil. Additionally, during winter months, wheat stubble effectively captures snowfall which then can further insulate overwintering sawflies from cold air temperatures.

Studies in Montana have shown that sawfly larvae can survive supercooling to -11°F, but that 50% of sawfly larvae die after eight hours at -4°F in the laboratory. However, unless sawflies are exposed to cold air temperatures via fall tillage, the coldest environment that an overwintering sawfly will experience is the temperature at ~4-inch soil depth.

While soil temperatures in the Scottsbluff area were some of the coldest in the state, they were still well above the -4°F or -11°F that would cause 50% or 100% mortality.

Other Insects
Although two of the major pests described above both overwinter in the soil (at depths of 4-8 inches), there are many other species that overwinter at different sites, including on the soil surface, on or inside of plants, in crop residues, and in protected structures like buildings or rock faces. Insects that have overwintered in more exposed areas without insulating snow cover would have been subject to the colder air temperatures in January and likely experienced some mortality. However, some insects have developed amazing adaptations to survive the cold, such as freeze tolerance, where they can physically withstand the freezing of their body liquids, or they are able to produce their own biological antifreeze to prevent body liquids from freezing at low temperatures.

Conclusions
Unfortunately, temperatures at most locations where western corn rootworm, western bean cutworm, and wheat stem sawfly typically overwinter have not reached sustained periods of low enough temperatures to cause considerable mortality. The exception would be the chance for higher mortality of WCR and WBC in January in the Scottsbluff region.

We recommend that scouting and management practices are continued as planned in 2025, and as informed by pest pressures observed in 2024, rather than relying upon this winter’s weather to provide adequate control of pests. However, weather between now and summer could still impact insect survival; for example, very wet soil conditions in spring can reduce WCR survival as larvae hatch out and potentially drown.

Source: Julie Peterson - Extension Entomologist, Ana Lima - Post-Doctoral Research Associate, Alisson da Silva Santana - Post-Doctoral Research Associate, Department of Entomology, Justin McMechan - Crop Protection and Cropping Systems Specialist, Pin-Chu Lai - Extension Entomologist, Jeff Bradshaw - Director of the Doctor of Plant Health Professional Program (Cropwatch – April 17, 2025)

Integrating Livestock for Weed Management
In some cases, weeds may not be a problem but an opportunity. Some livestock species, such as goats and sheep, prefer browsing on broadleaf plants and shrubs, which cattle might avoid. Incorporating multi-species grazing can help control certain weeds naturally while diversifying farm income. This approach can reduce reliance on herbicides and promote a healthier pasture ecosystem.

Weed Control Strategies
If control measures are necessary, consider the following strategies based on weed life cycles:

Winter Annuals (e.g., Downy Brome/Cheatgrass)

• Germinate in the fall, overwinter, and grow rapidly in the spring.
• Fall control is ideal, as spring control must occur in a short window before seed production.

Summer Annuals (e.g., Marestail, Russian Thistle, Foxtails, Barnyard Grass)

• Germinate throughout the summer, making total control difficult.
• Control when plants are young and prevent seed development to reduce future infestations.

Biennials (e.g., Musk Thistle, Plumeless Thistle)

• Form a low-growing rosette in year one and bolt to produce seeds in year two.
• Control during the early bloom stage to minimize regrowth and prevent seed production.

Perennials (e.g., Leafy Spurge, Canada Thistle, Spotted and Diffuse Knapweed)

• Develop deep root systems, allowing regrowth even after repeated control attempts.
• Control before early bloom when plants are using stored root reserves and follow up in the fall before frost to further weaken plants.

Shrubs

• Some species, like cedar, grow from above-ground buds and can be controlled through cutting, herbicides, or fire.
• Others, such as sumac and locust, regenerate from below-ground buds, requiring complete removal or chemical treatment for effective control.

Herbicide Considerations
Producers planning to use herbicides should reference Extension Circular 130, 2025 Guide for Weed, Disease, and Insect Management in Nebraska, available online or at local extension offices. Always follow label directions and consider timing, application rates, and environmental conditions for the best results.

Early Spring Weed Control Strategies
For producers looking to get ahead of weed issues in the spring, early action is key. Focus on the following strategies:

• Scout Pastures Early – As soon as temperatures begin to rise, check fields for emerging weeds, especially in areas prone to stress or disturbance. Pay special attention to rosettes of winter annuals and biennials. These can be easily missed, and control is more effective before they begin bolting.
• Target Winter Annuals – Species like Downy Brome and Shepherd’s Purse complete their life cycle early in the season, so herbicide applications should occur before flowering and seed production.
• Use Timely Grazing or Mowing – Grazing livestock or mowing can suppress early-growing weeds before they become competitive with desirable forages. This can be a stand-alone control strategy or used to delay growth for later herbicide applications.
• Soil Fertility and Overseeding – Fertilizing appropriately and overseeding thin pastures can improve forage competition and reduce opportunities for weed establishment.

Drought Considerations
Drought will often open opportunities for weeds to get a foothold by weakening desirable forages. Many of these will be annual weeds that appear in the first few years following drought. Through careful grazing management, some of these weeds will disappear on their own as rangeland and pasture conditions improve and desirable forages are able to outcompete weedy species. Control options can be used if weeds are persistent; however, if rangeland or pasture health is not good, other weedy species may grow rather than desirable forages. In this case, overseeding may be advisable.

Conclusion
Weed management in pastures and rangelands requires a proactive approach. Regular monitoring, maintaining healthy pastures, and using a combination of grazing management, mechanical control, and herbicides, when necessary, can help keep weed pressure low. By staying vigilant and adapting management practices, producers can ensure productive pastures that support healthy livestock and sustainable operations.

Source: Ben Beckman - Nebraska Extension Educator, Ryan Benjamin - Nebraska Extension Educator (BeefWatch – April 1, 2025)

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