52 
EASTERN SHADE TREE CONFERENCE 
the buds, and the pitch flow resulting from larval injury may be easily 
mistaken for this. If control measures against the shoot moth are effi¬ 
ciently carried out, treatment of the trees every other year should suffice 
unless there are untreated infested trees in the immediate vicinity. 
The recovery of root-injured pines, and new plantings should be con¬ 
sidered. Any form of injury which retards the growth of trees suscep¬ 
tible to shoot moth attack tends to increase the severity of the injury 
caused by the insect. This is particularly true of red and Scotch pines. 
If pines are to be planted in the region where the shoot moth is abun¬ 
dant, species highly susceptible to the shoot moth, as red and Scotch, 
should be avoided unless proper care of the trees in the future is assured. 
The spruce sawfly is a defoliator of native and exotic spruces. In the 
forests of eastern Canada and northern New England it is a very serious 
pest, often completely stripping the foliage from the trees. In Con¬ 
necticut the insect is found throughout the state, and several ornamental 
Norway spruces in the state park at Kent have been entirely defoliated. 
Partial defoliation has occurred on spruces elsewhere. 
This insect has three generations a year in southern New England. 
The adult female lays its eggs in slits in the needles, and these hatch 
in about a week. The larvae, which are light green in color when young, 
and green with longitudinal white stripes in the last two feeding stages, 
eat the needles, confining their attack to old foliage the first part of the 
summer but feeding on the needles of the current year late in the season. 
The cocoons are brown in color and are found in the litter under the tree. 
The winter is spent by the larvae in these cocoons, and some of the 
larvae may remain in the cocoons up to five years before pupating. 
This tendency to prolong dormancy results in the reinfestation of spruces 
by the same generation over a considerable period of time. Where 
three generations a year occur, the peak of attack comes late in the sea¬ 
son. The preference for old needles often results in the partial defolia¬ 
tion of spruce, accompanied by weakening of the trees, for several 
years before death occurs. 
Sawflies are very susceptible to arsenical poisons, and spruces can be 
protected against this insect by spraying with a mixture of 3 pounds 
of lead arsenate and 12 ounces of fish oil in 100 gallons of water. The 
application should be made when an infestation is found. 
If an attack of the sawfly on a spruce tree is accompanied by a gall 
aphid infestation, and these two factors are added to any other condition 
inimical to vigorous growth, the result is a tree which survives with 
