18 BULLETIN 899, U. S. DEPARTMENT OF AGRICULTURE. 
ing and applying this material is 1.08 to 1.42 cents per linear foot 
(depending upon the width of bands used) whereas the sticky com- 
pounds on the market cost 2.56 cents per linear foot. An additional 
feature is that bands of this material may be retouched or resurfaced 
and kept in working condition each year with very small cost. Its 
efficiency in barring caterpillars also compares favorably with the 
sticky material. 
If small apple orchards are to be protected where there is a severe 
infestation of the gipsy moth and where it is impossible to have such 
orchards sprayed at the proper time, the egg clusters may be treated 
by hand and gipsy moth tree-banding material applied economically 
and with good results. 
Injury to the bark of trees is negligible and in no case has there 
been any more injury noted than with the best banding materials 
now on the market. It is not advisable, however, to band very young 
fruit trees directly, as a slight thickening of the bark takes place at 
that point, which does not add to the beauty of the tree ; furthermore 
insect attacks on trees of this size can be handled more advanta- 
geously by spraying. 
The width of the band to be used against tree-climbing cater- 
pillars can only be determined by the degree of infestation but it is 
usually not practicable to apply a band of smaller dimensions than 
if by A i ncn m order that sufficient material be used so that the 
bands will not dry out too quickly. Bands of these dimensions were 
found to be the most economical and practical in the extermination 
work against the gipsy moth in the border territory and are recom- 
mended where caterpillar infestations are light or of a medium 
degree. Double bands of the above dimensions or broader bands, 1J 
inches wide or more, will be necessary only when the infestation is 
extremely heavy. The bands are economically and conveniently ap- 
plied by the use of a pressure gun made for the purpose. 
Caterpillars are barred by gipsy moth tree-banding material when 
the latter is in good condition, making it a physical impossibility for 
them to cross. The softness and greasiness of the material are such 
that large proportions of small larvae venturing into it become en- 
tangled, embedded, or so smeared with oil that death results. 
Observations have been made on some insects other than the gipsy 
moth against which this material might be effective, and it is prob- 
able that its use should give equal protection against some of them. 
If an organization for insect control work should require large 
quantities of this material annually, it should equip itself with 
apparatus for making same. On the other hand, for the owner of a 
few apple and shade trees it would not be so profitable to make the 
material on a small scale, although it can be readily done. 
