83 



among the trichomes of the leaves, but during the warmer periods of the 

 day a few were found usually crawling about the under surface of the 

 leaves, chiefly close to the main veins. 



Foliage was examined after a light frost late in August, and again 

 after a killing frost early in September. In the first instance relatively 

 few mites remained among the trichomes, and after the killing frost 

 none were found on the leaves, but a much smaller number^ten to twen- 

 ty — was found in the axils of the leaves, and around the young buds 

 where they seem to have taken shelter. Three instances were observed 

 in which a single mite, and another in which two, had pressed into the 

 young buds, just beneath the outer scale-leaves. 



An unexpected interruption in the observations made it impossible 

 to trace the effect of cold upon the mites, and to study their method of 

 passing the winter, if it actually occurs. Twigs collected through the 

 kindness of Mr. Charles Gemmill, student in Lebanon Valley College, 

 Annville, Pennsylvania, were sent me early in October, but I was unable 

 to locate the mites in any of the buds, or in the axils of such leaves as 

 remained attached to the twigs. None of the buds showed any swelling 

 or enlargement that could suggest the "big bud" similar to that observed 

 in the black-currant infested with Eriophyes ribis (Nalepa). Miss Tay- 

 lor (Jour. Agri. Sci., Vol. 6) in 1914 described the enlargement of buds 

 on black-currant in England, when so infected. In that instance the 

 mites penetrate the buds, causing them to swell, and if badly infested, to 

 die without opening. She found the mites to breed throughout much of 

 the year, and to migrate in the spring when the buds are opening. This 

 may be suggestive of the possible mode of hibernation of Eriophyes 

 (species undetermined) in the maple, but without producing hypertrop^ 

 of the buds. 



Similar stunted growth of Norway maples was observed in other 

 towns, and occasionally along the highways of Lebanon and Dauphin 

 counties in Pennsylvania, in sufficient numbers to suggest a wide dis- 

 persal of these mites through the agency of birds or insects rather than 

 by the wind. English sparrows crowded into the trees in large numbers 

 in Hershey, and it is quite possible that they may carry many of these 

 small mites on their legs and body, from tree to tree, and even from vil- 

 lage to village in their migrations. 



Though the trees showed no very serious ill effects fi'om the attack 



