Description:

Adults are moths with light-brown wings marked with dark-brown, transverse, wavy lines.  The hind wings are lighter brown, without crosslines.  A dark brown tuft of hair covers the back of the thorax.  Moths have a wingspan of about 1 1/2 to 2 inches (37 - 50 mm).  Immature larvae are reddish-brown, with narrow cream colored lines that extend the length of their body.  Mature larvae are black, nearly 2 inches (50 mm) long, and thickly covered with long, dirty-white or grayish hairs (Figure 22). 

Damage:

Larvae feed in groups but do not form webs.  They are capable of eating all the leaves on small trees or on individual limbs of large trees.

Seasonal History:

The walnut caterpillar overwinters as a pupa in the

When to Control:

Control is necessary only when the insects are numerous in a grove, but it should be done when the larvae are small.  Walnut caterpillars clustered on the trunk or limbs of a tree may be destroyed by crushing or burning