14 BULLETIN 1142, U. S. DEPARTMENT OF AGRICULTURE. 
caterpillars to cross paste bands by means of interposed gipsy moth 
tree-banding material bands were unsuccessful. In one instance, 
indeed, the caterpillar finally crossed the gipsy moth tree-banding 
material band. In the latter instances the two types of bands were 
of the same dimensions as regards height and width; about -^ inch 
and 1 inch, respectively. 
SUMMARY AND CONCLUSIONS. 
That the two factors of (1) odor, and (2) soft and semiviscid con- 
dition, operate together in enabling the gipsy moth tree-banding 
material to halt the caterpillars in their efforts to ascend to the 
foliage, was clearly demonstrated by the qualitative tests described 
in this paper. The first series, in which the solid odorous bands 
were used, could not be considered conclusive, for physical or tech- 
nical reasons (p. 7), but it indicated clearly that the first element, 
namely, odor, exercises at least a restraining influence. The second 
series, in which bands made of actual gipsy moth tree-banding ma- 
terial were used, demonstrated satisfactorily that the soft and semi- 
viscid, or viscous, condition of the material is the basic or primary 
factor. The odor restrained, indeed, but when acting alone did not 
completely check ; whatever " dislike " or " fear " it inspired wa* 
overcome sooner or later. 15 This series approximated closely to actual 
conditions, especially in the case of the narrowly bridged bands, in 
which the odor, after the strips of cloth became saturated with the 
material, was but little if at all interfered with or masked; indeed, 
the total odor emitted by some of these bands was far greater than 
would have been emitted, under the same conditions, by the smaller- 
sized " standard " band, 16 the odor being strong enough in the warm 
and rather confined atmosphere of the laboratory to irritate to a 
considerable degree, at a distance of about 2 feet, the nasal membrane 
of the writer. The various check bands used, namely, flour paste, 
flour-molasses, molasses, and also a commercial sticky tree-banding 
material, served very well, and if the last three were somewhat more 
viscid or "gluey" than the bands made from the gipsj^ moth tree- 
banding material, this fact was offset by the greater odor given off 
by the large size of the latter bands. 
The caterpillars, it should be added, seemed to " dislike " or " fear " 
the odorless and nonirritating check bands in proportion as they were 
viscid, or " sticky," and they reacted to these very often, especially to 
the more viscid, fully as promptly as to the gipsy moth tree-banding 
material bands. This fact is further evidence of the importance of 
the viscid factor in the banding material, and is of value, obviously, 
in the elaboration of an efficient barrier band not only against gipsy 
moth caterpillars but also against any species of similar behavior. 
An illustration of the practical operation of this fact is perhaps seen 
in the efficiency of newly applied or newly combed bands of a com- 
mercial sticky tree-banding material, the odor or exhalation of which 
is weaker and otherwise less repellent than that of the gipsy moth 
tree-banding material, especially on warm days. An atmosphere 
consisting of, or heavily charged with, the exhalation or volatilized 
portion of the latter material, as in a container, will disable a cater- 
15 In nature, in re«oonse to such stimuli as light (positive heliotropism), and more 
especially, hunger. — h " fear " would probably be overcome speedily. 
16 See footnote on p. 4. 
