Saturday, April 21, 2012

Week 16: Tent Caterpillars

Moths of the Week

Eastern Tent Caterpillar - Malacosoma americanum (#7701)
Forewing: male 13mm

In early spring the silky white tents of the Eastern Tent Caterpillar are a common sight in trees across much of East Texas.  Along with those tents are limbs that have been stripped clean by the ravenous caterpillars.

As the spring progresses the caterpillars come down out of their trees and begin looking for a place to build a cocoon.  During this time it seems that these blue and green caterpillars can be found just about everywhere.

In early to mid-April the adults eclose.  Some mornings I have had a dozen sitting on the wall by the porch lights.  The males are smaller and more gray in color; the females are a brighter brown and considerably larger.

Forest Tent Caterpillar - Malacosoma disstria (#7698)
Forewing: 11mm
A close cousin to M. americanum, this moth is less common than its larger cousin in East Texas.  The Forest Tent Caterpillar is easily distinguished by its smaller size and dark AM and PM lines instead of pale.  They also showed up a little later I found my first Eastern Tent on April 10th while Forest tent did not show up until the 18th.

The Forest Tent Caterpillar does not actually build a "tent" but instead builds a silky mat where the caterpillars gather.

Other Moths This Week

Spiny Oak-Slug Moth - Euclea delphinii (#4697)
Forewing: 12mm
Also reported in Zones 3,6

Four-spotted Palpita - Palpita quadristigmalis (#5218)
Forewing: 16mm
Also reported in Zones 1,3,4,5,6

Clinton's Underwing - Catocala clintonii (#8872)
Forewing: 20mm
Also reported in Zone 5


  1. What do we do about hordes of tent caterpillars?
    Falling into the neighbors pool!

  2. I think it would be best to get them before they leave the tent. Cut out the tent and dunk it in soapy water. You could put up bird houses to encourage birds to stay around the pool; Bluebirds will eat a lot of tent caterpillars.

  3. I'm doing a bug project for my science class and your website was helpful in classifying some of the moths that I caught for it. Thanks