10 BULLETIX 1093, U. S. DEPARTMENT OF AGEICULTURE. 



destroyed will have expanded into new shoots, and feeding is then 

 confined almost entirely to the stems of these shoots, not to the leaves 

 and buds. (PI. I. Fig. i.) In this way a large percentage of the new 

 growth may be entirely destroyed, provided the infestation is suffi- 

 ciently heavy. The same habit of feeding is continued through the 

 later stages, until the supply of new growth is exhausted, then the 

 older leaves may be attacked, and the vines stripped, provided, again, 

 that the caterpillars are numerous enough to be forced to seek this 

 less attractive food. 



It is obvious that a few caterpillars can do a great amount of dam- 

 age, first to the terminal bud from which is produced the season's 

 fruit, and second by causing a branching growth of the plant. This 

 damage to the terminal bud may occur before the owner realizes that 

 his bog is infested. 



FEEDING HABITS OX WHITE OAK FOLIAGE. 



In the observations made in 191&-19 concerning the dispersion by 

 wind of first-stage gipsy moth larvae, it became evident, from the 

 count of larvse taken from the traps, that there are two periods of 

 the da}' during which maximum dispersion occurs. From this fact 

 it was inferred that there are, correspondingly, two daily periods 

 of activity, as the larvae would be more likely to be carried by the 

 wind when crawling over leaf surfaces, limbs, or trunks of trees 

 than when at rest. To verify- this inference it was decided to make 

 a study of the habits of first-stage larvae as they are found in tree 

 tops, where the earliest feeding usually appear.s, and where also 

 the relation between the feeding habits and wind dispersion could 

 be more satisfactorih' studied. 



A white oak about 30 feet high was selected near the border of 

 Mudd}' Pond Bog. Around this tree was erected a tower 16 feet 

 square at the base. 8 feet square at the top. and 25 feet high. A 

 flooring was placed around the branches on top of this tower, thus 

 bringing the upper 5 feet of the terminal branches in position for 

 close examination and observation of the movements of young 

 larv£e. (PI. IV.) 



On May 19, 1919, when observations were started, the leaves on 

 this tree had begun to unfold, some of which would measure an inch 

 in length, giving considerable protection to the young larvae, as 

 well as supplying food. It was found that the first feeding by first- 

 stage gips}' moth larvae after reaching the foliage was confined to 

 the leaf hairs, principally on the underside of the leaves. After 

 feeding in this manner for a daj- or two they began to feed on the 

 tissue of the leaf, later eating through the tissue. The information 

 relating to the feeding periods of first-stage gips}- moth larvae, col- 

 lated for the whole period of obserA-ation. furnishes what can be 



