If you made a list of the biggest annoyances to farmers, insects would be near the top. No matter what time of year it is, there are always several types of insects attempting to make a meal out of your grain crop. How do you protect wheat crops from insects? Are there any beneficial insects out there? Let’s take a look.
How to Determine If Insects Are the Problem
First off, there are a number of things that cause problems for plants. The condition of your grain could be related to weather, temperature, or a handful of other things. And even if you see an insect among your grain crop, how do you know it’s to blame? There are some symptoms you can check for.
Aphids, for example, drink the sap right out of the plant as it’s growing. They have a mouth that looks almost like a straw, and they use it like one to drain the sap. They’re not picky. Aphids will drink sap from wheat, corn, or pretty much any grain. You can tell because the plant starts developing yellow spots, then it begins to wilt. In some cases, black mold starts growing on the plant as a result.
Armyworms also create problems for a grain harvest. The average armyworm, according to the Kansas State University Extension Service, eats about 43 inches of wheat leaves during its larval stage. Keep in mind that only takes three to five days, so this insect can do a lot of damage quickly.
Another major pest is the stink bug, but not for the reason you might think. It’s not the smell, but rather the bug’s spit that is the problem. According to the U.S. Department of Agriculture, a stink bug’s saliva is poisonous to grain crops. How can you tell that one is attacking your plant? The stink bugs enjoy eating wheat kernels.
Finally, there’s the Hessian flies, which also like to go after wheat crops. The symptoms of a Hessian fly attack include poorly filled wheat heads and weak stems.
One Solution Is to Let Nature Take Its Course
So now that we know the major insects causing problems, how do we stop them?
One way to protect wheat crops from insects is to let other insects eat them. The Penn State Extension Service explained in a piece on its website that “ladybugs feed on aphids, please encourage them.” The same goes for beetles and spiders. All three insects enjoy snacking on aphids or stink bugs.
Check armyworms for fly parasites (tiny yellow eggs) near the head of the larvae. These fly parasites are destined to kill the armyworm.
With these things in mind, your insect problem could be solved by simply letting nature take its course. If letting more insects loose around your crop doesn’t sound like a good idea, the Penn State Extension staff has another option when it comes to aphids.
Douse Plants with Homemade Insecticidal Soaps
“One of the safest ways to get rid of aphids is to douse the plant with insecticidal soap,” the Extension website states.
What is insecticidal soap? It’s a home remedy of sorts, one that farmers can easily assemble on their own. You take one cup of oil (any type can be used, from peanut to corn oil, soybean or vegetable) and mix it with one tablespoon of dishwashing liquid. Mix two teaspoons of this soap for every cup of warm water until you have enough to use on your whole crop.
What does this do? Well, according to the Penn State staff, it weakens the outer shell of the aphids and causes them to dehydrate. Once the insects become too uncomfortable, they’ll stop eating your crop and move on.
Insecticides Are a Temporary, but Untenable Solution
When it comes to insecticides, fenpropathrinm, dimethoate, endosulfan, and formetanate hydrochloride are considered to be the most effective. While these chemical controls are an option, the North Carolina State Cooperative Extension warns they’re not a sustainable one in many ways.
“Broad-spectrum (insecticides) have reduced the severity of damage in many crops, but they have also increased production costs and disrupted IPM [integrated pest management programs], resulting in greater risk to non-target organisms and secondary pest outbreaks,” the Cooperative Extension staff said on its website.
Instead, the NCSU Extension staff also looks to nature for a long-term solution. On their website, they give an example of a brown marmorated stink bug, an Asian native that has started making its home in Southeastern U.S. farms.
“In its native Asia, BMSB is not a major pest, partly because of tiny parasitic wasps that destroy large numbers of BMSB eggs.”
As I mentioned earlier, sometimes letting nature take its course is the best solution.
Protect Wheat Crops from Insects Post-Harvest
As I’ve written before before, the U.S. soybean and corn harvests in 2018 were two of the largest in history. As a result, more grain is being stored for months or even years, rather than weeks.That can be a potent feeding ground for insects, especially grain weevils.
“Stored grain pests can cause significant losses to stored grain if left unchecked,” says a 2018 report from the University of Arkansas Division of Agriculture. “This is particularly true for wheat because it is often in storage throughout the hot summer months when insects are most active.”
Now that many farmers are also storing corn and soybeans trying to outwait tariff wars and other market woes, even more grain is at risk of insect infestation during hot summer seasons. I wrote a whole post last year about how to prevent insect infestation in grain stored long-term.
Temperature Monitoring Is the Best Pest Control Solution for Stored Grain
You have to make the stored grain environment as unappealing as possible for insects. It starts with never mixing old and new grain in one bin. One way to protect stored wheat crops from insects (or any grain for that matter) is by removing all the old grain. Move it to a separate bin if you aren’t ready to sell.
“Before placing fresh grain into a bin, floors should be swept clean of all old grain. Any spilled grain near the outside of the bin should also be removed,” the Arkansas staff says in the 2018 report. “One area growers often forget to clean is the augers. Once all bins and equipment have been cleaned, bin floors and walls should be treated with a residual insecticide just prior to placing fresh grain in the bin.”
Finally, once the new grain has been placed in the bin, you have to monitor moisture, and the only way to do that is to monitor temperature. More moisture means not only is the bin susceptible to fungus, but it is an excellent breeding ground for insects – especially at higher temperatures.
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