GIPSY MOTH TREE-BANDING MATERIAL. 15 
terial penetrating the body and spiracles of those venturing into the 
bands. 
EFFECT ON BARK OF TREES. 
Several experiments have been conducted since 1915 to determine 
the extent of injury, if any, to the bark of forest, shade, and fruit 
trees that were banded. Trees were selected with rough and smooth 
bark, as also peach and apple trees of various ages. In no case was 
material injury done to the bark with the gipsy moth tree-banding 
material, the bands being 1 to 2 inches wide. The oil of the bands 
sometimes penetrates ^ to -^ inch deep on rough-bark trees. Wher- 
ever slight surface injury was noted from the penetration of oils, 
new cells formed in the cambium layer, which gave the bark a 
slightly swollen appearance at that point. Such slight local injury 
did not affect the growth or vigor of the trees, or the production of 
fruit in the case of bearing fruit trees. 
Bands 6 to 10 inches wide were placed on peach trees aged from 
1 to 15 years. These were applied at the base partly beneath the 
surface of the soil with the idea of noting injury to the tree should 
this material prove effective in preventing egg deposition of the 
peach-tree borer (Sanninoidea exitiosa Say). No material injury 
was noted to the bark save the slight local killing of cells in the 
outer bark, as was cited above with the forest and fruit trees. This 
was overcome by the growth of new cells in the cambium layer of the 
bark. The vigor and fruiting of the trees were not impaired so far as 
could be detected. 
VALUE OF BANDING APPLE TREES LOCATED NEAR WOODLAND 
INFESTED BY THE GIPSY MOTH. 
Many apple orchards or scattering apple trees in New England are 
located near or bordering on woodland infested with the gipsy moth. 
After the egg clusters on such trees have been treated with creosote 
a reinfestation the same season sufficient to damage or defoliate the 
trees badly often occurs. This condition is brought about by wind- 
spread of newly hatched caterpillars and the migration into the trees 
of small larvae that hatched in near-by hidden places and of larger 
caterpillars which crawl from the woodlands. This condition can be 
relieved by spraying with arsenate of lead just after the caterpillars 
have hatched and once or oftener during the active feeding season. 
The owner of a small number of apple trees does not usually possess a 
spraying outfit that will cover large apple trees thoroughly and he is 
obliged to depend upon the local town power sprayer or private jobber 
for this work. The operators of such sprayers always have a large 
amount of work to do with the equipment at hand, consequently many 
orchards are sprayed late in the season after caterpillars have almost 
defoliated them, or they are not sprayed at all. 
