The larvae stage of tent caterpillars is most destructive to certain types of trees in East Texas, including oaks.  These leaf-eating caterpillars can be identified by their dark brownish body color, with subtle blue and yellow lines extending lengthwise and white spots down the middle of the back.  They are frequently found clustered together on trunks of trees but will eventually climb into branches to reach the foliage.

These larval caterpillars generally appear in April or May but can be found as early as February and at times can appear cyclically in great numbers.  They devour leaves which can cause slowed growth or die-back to certain parts of the tree they inhabit.

Typically, this larval stage is present from 2-6 weeks, during which they can often be found crawling on walkways, other plants (not a targeted food) and on outer walls of homes, which makes them a nuisance to humans.