Extremely heavy infestations have been reported from South Texas to the Red River and from the grain growing regions of Central Texas to the Louisiana border. Counts are equally high from Arkansas to Florida and as far north as Oklahoma, according to Robinson. A month ago, Robinson and other entomologists were warning of the possibility of heavy infestations of armyworms when rains returned. From years of observations, it's known that armyworm populations often explode when rains follow an extended drought. But the severity of this year's infestation caught Robinson and other entomologists by surprise.
Armyworm moths migrate in the millions northward from South Texas in the spring and summer.
As part of their natural life cycle, each moth will deposit a clump of 50 or more eggs on individual blades of grass. During a drought, most of the eggs dry up or die within a few days. If the armyworms do hatch, they find nothing to eat and die. The moths are persistent, however, and continue to migrate and lay eggs throughout the summer, drought or no drought. When their egg- laying coincides with a rainfall, the armyworms successfully hatch in droves and immediately start maneuvers.