The Yellow-striped Armyworm is a daytime feeder, making it easier to spot its presence in a garden. It has some color variations, but a commonly recognized one is brown-black with bright yellow lines running down both sides of the body. Another variation is pale gray or taupe, and the top of each segment displays a pair of black triangles that point toward each other. It is possible for some to appear orange or have pinkish tones on the body. The head is black and has a pale 'V'-shaped mark on it.
Eggs are slightly flattened spheres and are laid in large clusters of hundreds underneath leaves that are food sources. They hatch within a week of being laid. There are six instars and the caterpillar can pass through all of them within a month. Once ready to pupate, the larva burrows underground, building a silk-lined cell for itself there. Pupation can last about two weeks, give or take a week, depending on the environment. It emerges as a brown moth that has a striking pattern of bands and color patches on its wings.
This caterpillar is an agricultural pest. Commonly affected crops include soybean, wheat, cotton, alfalfa, clover, grape, sunflower, and tobacco. Its diet also includes popular vegetables like tomato, pepper, cabbage, corn, lettuce, onion, potato, sweet potato, beans, and melons. Turf (grass) and flowers are also edible. When young, groups of small caterpillars skeletonize the leaves of these plants. As they mature, caterpillars disperse to seek more food sources. It is possible for a small larva to hang on a string of silk that catches wind and be blown to neighboring plants. Trenches between rows can help deter crawling between them. The Yellow-striped Armyworm is eaten by various garden bugs and is attacked by some parasitic wasps. Control using insecticide (both organic and conventional) is effective; be sure to follow the label's instructions.
The map above showcases (in blue) the states and territories of North America where the Yellow-striped Armyworm may be found (but is not limited to). This sort of data can be useful in seeing concentrations of a particular species over the continent as well as revealing possible migratory patterns over a species' given lifespan. Some species are naturally confined by environment, weather, mating habits, food resources and the like while others see widespread expansion across most, or all, of North America.*NOTE: States/Territories shown above are a general indicator of areas inhabited by the Yellow-striped Armyworm. Insects generally go where they please, typically driven by diet, environmental changes, and / or mating habits.