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BY Todd Amenrud on Aug. 31, 2016

Army Worms: What You Need to Know

The fall armyworm or (spodoptera frugiperda) can be a hunter’s worst nightmare. This forage feeding pest can quickly demolish and destroy a food plot in a matter of days. The story sounds the same, “My plot was growing great, a week or so later I returned to find that my plants had been destroyed. What happened? ” This is a classic example of fall armyworm damage.

Life Cycle

This insect over-winters in warm climates along the gulf coast. In the spring of the year adult moths migrate north, beginning the first life cycle of the worm. These moths lay their eggs in masses of 50 to 100, covering them with a fuzzy, gray substance that comes from the female. In just a few days the eggs hatch and small larva begin searching for food. Unlike other army worms, the “fall army worm” feeds continuously! They will feed for two to three weeks before pupating into the soil. This feeding period is when they are most likely to destroy your food plots.

The worms begin to migrate north during late July through early August, feeding on many kinds of crops and grasses. The first sign of army worm infestation can be small circular areas in your plot that look to be turning brown. These brown circular areas will grow quickly as the worms grow older and require more green vegetation to survive. There may be four to five generations of army worms that cycle throughout one summer.

By the end of the fifth generation their numbers can be mind boggling. Fall army worms can be identified by a distinct stripe on their back, but often vary in color depending on the vegetation they’ve ingested. They will also have a light colored, inverted Y stamped on the head of the larva and four black dots centered on the abdomen. The larva can range in size from a three day old being a quarter inch long to a fully matured worm that may reach an inch or more.

Death Cycle!

Controlling these pests can be costly but it may be the difference between having a food or not. It is important to scout your property on a regular basis. The earlier that fall army worms can be detected, the easier they are to control. Once a worm reaches the adult stage they become less susceptible to insecticides and harder to kill. Besides, once they have become adults the majority of the damage to your plot has already been done.

There are several different insecticides that will control fall army worms. Consult with your local Co-op, Farm or Feed store, or contact BioLogic to see what applications are recommend. Hopefully you will not have to deal with these pests, but be prepared just in case.


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