Individuals who use agricultural chemicals are responsible for ensuring that the intended use complies with current regulations and conforms to the product label. A&T State University nor discrimination against similar products or services not mentioned. The use of brand names and any mention or listing of commercial products or services in this publication does not imply endorsement by NC State University or N.C. Recommendations for the use of agricultural chemicals are included in this publication as a convenience to the reader. The butternut woollyworm has only one generation of caterpillars each year. At first, the small caterpillars chew small holes between veins, but as they grow to 7/ 8 inch long, they consume entire leaflets leaving behind only the larger veins and midrib.

Eggs hatch in about a week in mid May and tiny butternut woollyworms begin to feed on the underside of the leaves. Females lay their very small, creamy-white eggs inside living leaves using their sawlike ovipositors (hence the name sawfly) to cut small slits into the midribs on the upper surface of leaflets in which to deposit her eggs. The wings are held flat over the back when at rest. These sawflies have black bodies with white legs. The April prepupae molt into pupae that soon develops into dark flylike insects about 7/ 16 inch long (males are smaller) that emerge from the cocoon to mate.

The rest of the summer, winter, and spring is spent as a prepupae inside the cocoon.

When mature in mid July, the caterpillars crawl to the soil and spin a cocoon that incorporates soil particles. However, the caterpillars are covered with a thick, fluffy secretion that makes them look like nothing ever seen before! They feed in groups, which also contributes to their visual impact. Fully grown butternut woollyworm caterpillars are green with blackish spots and a black head. The butternut woollyworm, Eriocampa juglandis, is actually a sawfly caterpillar (sawfly caterpillars have ten pairs of legs - a pair of legs on every segment - whereas moth and butterfly caterpillars have eight or fewer pairs of legs). Description and Biology Skip to Description and Biology

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