What kind of caterpillar is this that was found munching on the leaves of a pecan tree?
These are walnut caterpillars (Datana ministra). Walnut caterpillars are native to the US and are common in the Southeast. Eggs are laid in masses and the larvae remain congregated throughout their juvenile stages. Though they bare a slight resemblance to fall webworms, an easy way to distinguish them is that walnut caterpillars do not create and feed within a protective web. Instead, a single defoliated branch in late-summer is a tell-tale sign that they were present and have pupated and dispersed. While the damage appears concerning, mature pecan trees can typically handle it without any negative effects. Young trees with small canopies, or trees with multiple masses of caterpillars may require treatment to prevent excessive defoliation. Learn more about walnut caterpillars here.
This week’s question is from Justin Ballew, Extension Fruit and Vegetable Research Associate.
The South Carolina Grower 