﻿14 BULLKTIX HI-. U. S. DEPARTMENT OF AGRICULTURE. 



caterpillars to cross paste hands by means of interposed gipsy moth 

 tree-handing material bands were unsuccessful. In one instance,. 

 indeed, the caterpillar finally crossed the gipsy moth tree-banding 

 material hand. In the latter instances the two types of hands were 

 of the same dimensions as regards height and width; about. ,V 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 enahling 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 hands 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 was 

 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 gipsy 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 rewonfle to such stimuli as light (positive heliotropisni), and more 

 especially, hunjrer. — h " foar " would probably be overcome speedily. 

 10 See footnote on p. 4. 



