Two Tussock-haired Caterpillars

     Two unrelated species of small, common moths have attractive, tussock-haired caterpillars that we see here in the Middle Atlantic States, and throughout much of the eastern United States.  In fact, the hairy (really setae) caterpillars of these moth species are more noticeable and attractive than their adult, moth form. These two species are white-marked tussock moths and milkweed tussock (or tiger) moths, both of which have curious and pretty larvae completely covered by long "hairs".  Most birds and other animals would never eat such hairy creatures, which, of course, is good for both species.  And some peoples' skin is irritated if touched by the setae, which protect the caterpillars.
     White-marked tussock caterpillars are striking with red heads, many yellow or white, hair-like setae on their bodies, a black stripe aloog the middle of their backs, red, defensive glands on the rear of their backs, four thick, white tufts of setae standing up from their backs like tiny shaving brushes, and a long, thin tuft of grey or pale-brown hair at the rear. 
     White-marked, tussock caterpillars eat a variety of tree leaves early in summer.  Within  a few weeks each larva spins a gray cocoon with setae imbedded in it in tree bark crevices.  There, within a couple of weeks, they change to a small, brownish moth with wavy, dark lines on their fore wings.  At that time, they emerge from their pupae, but the females don't leave their cocoons.  Neither gender consumes anything.  Their only jobs now are for the males to fly to find a mate or mates, breed, mostly at night, and for the females to lay eggs.  Males soon die.  Each female lays up to 300 eggs in a mass on her cocoon still in a crack in tree bark.  She covers the egg mass with a protective froth she makes, a froth that soon hardens.  Then she dies.  There the eggs over winter.  The caterpillars hatch early the next summer and start another generation of this beautiful species of caterpillars.
     The larvae of milkweed tussock moths  have black heads, and thick, soft clumps of black, white and orange setae scattered all over their bodies.  They would be a hairy mouthful to any animal that tried to ingest them.  Again, most critters would never try. 
     This kind of caterpillar eats milkweed and dogbane leaves, plants that are related to each other.  That foliage has chemicals in them that the caterpillars store in their bodies to defend themselves against predatory critters that would eat them if they could.
     After a few weeks of eating milkweed and dogbane foliage, each milkweed tussock caterpillar makes a grey cocoon that has setae in it in the ground.  The larvae over winter in their pupae until early summer when they emerge from them. 
     Adult milkweed tussock moths are small, have gray wings, and yellow, hairy abdomens, each with an attractive row of black dots on top, which gives them the name milkweed tiger moths.  Females of this species lay eggs in masses only under growing milkweed and dogbane leaves, foliage their caterpillars eat.
     This summer, or succeeding ones, watch for these two kinds of beautiful, thick-haired caterpillars.  Each kind is handsome and interesting to experience.