Winter is spent in the adult stage, and the adults appear in early spring. Eggs are 
deposited in clusters around small twigs. The larvae feed gregariously until almost 
full grown and usually defoliate one branch before moving to another. Chrysalids 
are formed in June or early July. Adults soon appear and lay the eggs for a second 
brood. Larvae of this generation are present until September. They then pupate and 
the adults emerge to hibernate. There are one or two generations per year, depend- 
ing on location. 
The mourningcloak butterfly 1s of minor importance in the forest, but is some- 
times injurious to shade and ornamental trees. Infestations can be controlled by 
cutting and burning infested twigs and small branches. 
The viceroy, Basilarchia archippus (Cramer), occurs Over most of the United 
States and feeds on poplar and willow. The adult resembles the well-known 
monarch butterfly, Danaus plexippus (L.), but differs by being slightly smaller, 
having a narrow black line across the hindwings and only a single row of white 
spots in the black marginal band of the wings. The full-grown caterpillar is about 37 
mm long. The head is large, pale green, and bilobed. Body segments one and two 
are pinkish to brownish; segments three to six and the sides of seven are brownish or 
greenish; the tops of segments seven and nine and nearly all of eight are pale 
pinkish or whitish; and the top of nine and nearly all of the last three are brownish or 
greenish. There are two barbed, club-shaped, brown tubercles on top of the second 
thoracic segment and two smaller ones armed with spines on the top of the other 
segments. There are two generations per year. The two related species, B. arthemis 
(Drury), the white admiral, and B. astyanax (F.), the red spotted purple, are 
found on poplar, willow, birch, black cherry, apple, and basswood. The caterpillars 
are similar in appearance to those of B. archippus. 
Asterocampa clyton (Boisduval & LeConte), the tawny emperor, occasionally 
seriously defoliates hackberry in the Lake States (7/4). Full-grown caterpillars are 
25 to 37 mm long. The body is greenish except for a yellow stripe down the back 
and a deep biue, yellow-bordered stripe on each side. The head is armed with 
branches, antlerlike spines, and there are two projections at the posterior end of the 
body. A. celtis (Boisduval & LeConte), the hackberry butterfly, is also occasion- 
ally abundant on hackberry in the Lake States. The caterpillar is greenish with a 
row of yellow dots down the back and three yellow lines along each side. Other- 
wise, it resembles the caterpillar of A. clyton. 
Family Megalopygidae 
Flannel Moths 
The bodies of flannel moths are covered with dense coats of scales and long 
crinkly hairs. The larvae are also densely covered with long soft hairs, with an 
intermingling of venomous spines. Females deposit their eggs in small batches, 
usually on leaves, and cover them with hairs from the abdomen. 
The puss caterpillar, Megalopyge opercularis (J. E. Smith), occurs throughout 
the Southern States where it feeds on various deciduous trees and shrubs. Forest and 
shade trees commonly infested include oak, elm, hackberry, maple, and sycamore. 
The adult moth is yellowish brown, with brownish spots on the wings, and has a 
wingspread of about 25 mm. The wings bear long, wavy, white hairs, especially 
along the veins. The larvae are densely clothed with long yellow and reddish-brown 
or mouse-gray hairs. The hairs on the rear end are taillike. 
Young larvae feed gregariously on the surface of the leaf and skeletonize it. Older 
larvae devour the entire leaf. Serious infestations have been recorded in Florida and 
Texas. Several thousand hectares of turkey oak were defoliated during an outbreak 
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