TIMOTHY DALY: Armyworms are on the march

Recently, many homeowners have noticed caterpillars feasting on their lawns. These insects are armyworms, and in some cases, they can damage lawns rapidly. They move in large numbers, marching side by side, which is how they got the name “armyworms.” Large numbers of caterpillars can sometimes be observed crossing roads and other paved surfaces. They have even decimated pastures consisting of acres of grass forage. However, the insects can be controlled, and their damage minimized despite their voracious appetites.

During the latter part of the summer into the fall, armyworms invade lawns throughout the state. Although their damage to established turf is primarily aesthetic, newly sodded areas are more vulnerable and attractive to these insects and can be severely harmed by their feeding. Armyworms will feed on all turfgrasses, but their preference is for bermudagrass. They consume only the leaf blades above ground and do not attack the roots. A small area of dead turf is the first sign of damage but will spread over time. The younger ones chew on the leaves, giving them a ragged, skeletonized appearance, whereas the older ones consume the entire blade to the ground. Often, birds can be observed clustering around the infested area. Although the birds eat the armyworms, they cannot consume enough to reduce damage. To determine if armyworms infest your lawn, pour water mixed with dishwashing liquid onto the grass. If the caterpillars are present, they will begin to crawl up the leaf blades.