Douglas County Conservation District                                                                         ~Helping People Help the Land~                                                                                                            

                                                                            PO Box 688, 7519 E. Hwy 86, Franktown, CO 80116

Tent Caterpillar

	Tent caterpillar nest
	Tent caterpillar larvae

About Tent Caterpillar

Live on chokecherry, plum, willow, ash, poplar and rose.  Mature larvae are 50 mm long and can be quite variable in pattern.  In general, most tent caterpillars are pale blue with an interrupted white stripe bordered by two reddish-orange stripes down the center of the back.  Moths are reddish-brown, have two oblique whitish stripes on the forewings and have a wingspan of 37 to 50 mm.

Eggs hatch when the first new leaves appear.  Larvae live in colonies and construct large silk tents around a fork or branches of trees.  These tents are enlarged as the larvae grow, enclosing the entire branch or even the entire tree.  Adults of tent caterpillars emerge in late summer and lay flat egg masses on twigs and branches.  There is one generation per year.

Larvae skeletonize leaves outside tents.  Infestations tend to be spotty and are often unrecognized until entire trees have been defoliated.  Severely infested tress are less vigorous and unsightly, but are rarely killed.

To Control

Spray leaves with carbaryl, acephate, diazinon, malathion, or Bacillus thuringiensis (B.t.) when tents first appear and caterpillars are small.  Caterpillars and tents on small trees can be picked off and destroyed.