398 MISC. PUBLICATION 657, U. S. DEPT. OF AGRICULTURE 
generally one generation a year in the Northeastern States, but farther 
south some species may have two generations, or at least one and a 
partial second. 
As all species of Datana are gregarious, the simplest method of con- 
trol in light infestations is to remove and destroy each colony. In 
heavier infestations spray with an arsenical or DDT (p. 52). For 
cautions in the use of these materials see pp. 25 and 34. 
One species is of particular importance as a pest of forest and shade 
trees, and several others are of lesser importance. A description of 
the larvae of those species that most commonly attract attention as 
pests, together with the food plants and general distribution of each 
are given here. 
The full- grown larva of the yellow-necked caterpillar (Vatana 
ministra ( Drury) ) is black and about 2 inches long, moderately 
clothed with white hairs. The neck is narrowly ringed with yellow, 
the cervical shield is waxy yellow, and the body has four narrow, pale- 
yellow, longitudinal stripes on the sides, narrower than the intervening 
spaces. The venter has a pale-yellow median line, and a line on each 
side interrupted by the bases of the legs. All legs are yellowish at 
base, the rest of the true legs and a band on the prolegs are black. The 
partly grown larva has the head and cervical shield black and the 
body reddish brown with yellowish stripes. 
This species occurs throughout most of the Eastern States west to 
Missouri and in southern Canada. Its food plants include apple, 
birch, blueberry, basswood, cherry, elm, hawthorn, oak, and other de- 
ciduous growth. Often it is abundant locally, particularly on un- 
sprayed apple trees. 
The full-grown larva of Datana angusii G. & R. is black with pale- 
yellow lines and is quite similar to D. minéstra, but can be distinguished 
from that species by its cervical shield being entirely black. This 
species is found in the Atlantic States west to “Illinois and north into 
southern Canada. Its larvae feed on beech, gray birch, butternut, 
hickory, and the oaks. 
The full-grown larva of Datana dreweli Hy. Edw. is about 2 inches 
long and moderately hairy. The head and body are black, with the 
cervical shield and anterior portion of the prothoracic segment 
honey yellow, and the tenth abdominal segment yellow except 
for the black anal plate and anal legs. ‘The body has 11 longitudinal, 
yellow stripes, narrower than the intervening spaces, and ‘the bases 
of the legs and corresponding spots on legless segments are dark yellow. 
The partly grown larva has the head, cervical shield, anal plate, 
thoracic and anal feet, and the abdominal feet outwardly black, and 
the body brownish with yellow stripes. This species is found in the 
Atlantic States, west to Ohio, and its larvae feed on blueberry, bass- 
wood, sassafras, and witch-hazel. 
The full-grown larva of )atana major G. & R. has the head, cervi- 
cal shield, the legs and corresponding spots on the legless segments of 
a mahogany red. The body is about 2 inches long, black, sparsely 
clothed with whitish hairs, and has four longitudinal rows of whitish 
(occasionally yellowish) spots on each side, and also three rows on 
the venter. The earlier instars vary in color and markings, but in 
general the head is blackish or dark red, the cervical shield and anal 
plate black or partly brown, the body varies from reddish to brownish 
