defoliated and killed. Fortunately, outbreaks usually last only 2 
to 4 years. 
Cutting practices designed to remove the jack pines that most 
commonly produce staminate flowers are helpful in preventing 
outbreaks (359). These trees are usually coarsely branched and 
large crowned, or suppressed and slow growing. The growing of 
hard pines in fully stocked stands or in groups; the elimination 
of large-crowned, ‘wolf’ trees; the utilization of trees before 
they become mature; and the encouragement of species suited to 
the site are also recommended (309). Parasites and a polyhedral 
virus disease aid in the control of infestations following periods 
of heavy defoliation. Rapid declines in populations have also been 
attributed to decreases in staminate flower production. 
A new subspecies, Choristoneura pinus maritima Freeman, has 
been found feeding on Virginia and pitch pines in Pennsylvania, 
Massachusetts, New Jersey, and Kentucky. Adults are larger and 
redder than those of the jack pine budworm (269). 
The large aspen tortrix, Choristoneura conflictana (Wlk.), oc- 
curs throughout the range of trembling aspen in Canada and 
eastern United States south to New Jersey and Ohio. Several 
other hardwoods also serve as hosts such as balsam poplar, large- 
tooth aspen, paper birch, willow, and alder. The adult is dull, 
light gray in color and has a wingspread of 25 to 35 mm. Full- 
grown larvae are usually dark green, sometimes almost black, and 
are 12 to 21 mm. long. The prothoracic shield is reddish-brown to 
black; the thoracic legs, black. 
In Canada, eggs are laid in flat clusters usually on the upper 
surfaces of leaves in June or July. First instar larvae feed gre- 
gariously on leaf surfaces during July, spinning much silk and 
webbing the surfaces together (fig. 1538). Later they move to the 
trunk in search of hibernation sites in rough bark or under moss. 
Here they molt and spend the winter in the second instar. The 
following spring, they climb the trees and mine the swelling buds. 
Later, they roll leaves and feed within the enclosures. Pupation 
occurs within the rolls, and adults begin to emerge in June (606). 
Many outbreaks have occurred in aspen stands in Canada. Serious 
defoliation has also been recorded in New England, New York, 
and Michigan. 
The oblique-banded leaf roller, Choristoneura rosaceana 
(Harr.), occurs in southern Canada and throughout most of the 
United States. It is recorded as a general feeder on the foliage of 
deciduous trees and shrubs. In Canada, it occurs most frequently 
on trembling aspen, paper birch, and willow but has also been 
observed feeding on Scotch pine. In New York, it has seriously 
damaged coniferous seedlings in nursery seedbeds (652). Seed- 
lings most seriously affected were those of white, Scotch, and red 
pines. The infestation is believed to have resulted from an inva- 
sion of the nursery from larvae developing on weeds or other 
vegetation surrounding the nursery. The adult is reddish-brown 
and has a wingspread of 18 to 20 mm. The forewings are marked 
with three dark-brown oblique bands. Full-grown larvae are 
greenish and about 9 mm. long. 
Winter is spent as young larvae in tightly-woven cases under 
bud scales or loose bark, or between leaves. The following spring, 
383 
