REPORT OF THE STATE ENTOMOLOGIST 



455 



The mite as occupant of the galls had been seen by Dr. Thomas 

 Taylor, microscopist of the U. S. Department of Agriculture, in 1872, 

 as appears from Glover's Report for that year, in which he states : 



" In May, many leaves of the pear-tree were observed to be covered 

 by dark-brown blotches somewhat like a fungoid growth, but upon 

 examination by Mr. Taylor, microscopist of the department, these 

 blotches were found to be inhabited by myriads of small mites almost 

 invisible to the naked eye. These mites appear to run all over the 

 leaves, but especially to burrow in the brown patches, which appear to 

 be entirely eaten out by them. Their bodies are long, cylindrical, 

 yellowish-white, with only two pairs of legs placed very far forward 

 toward the head, and they move with considerable agility. Tliey are 

 also marked with a multitude of rings, and have two long hairs or 

 bristles and two shorter ones on the end of the abdomen." 



A figure of the mite accompanies the above, and comparison is made 

 with the Typhlodromus pyri Scheuten, figured by Dr. Packard on plate 

 10 of his Guide. 



Nature of the Attack. 



In the early spring, as the buds are unfolding, the leaves may be seen 

 to be studded with small red spots or blotches which, on close examina- 

 tion, show themselves on each side, but more conspicuously on the 

 upper, as slightly thickened areas of the leaf. They soon pre- 

 sent a fuzzy appearance when seen under a lens, resembling a 

 particular form of fungus, for which they had been for many 

 years mistaken, it not being then known that they were galls 

 produced by a mite. On the under side of the leaf, a small 

 opening may be seen in each gall through which the mites emerge at 

 their maturity. The galls, at first red, or red on one side and green on 

 the other, soon change to blackish or brown upon the destruction of 

 the cells and tissues of the affected spot. If a section is made of a gall, 

 the two surfaces are seen to be separated by a cavity of disorganized 

 tissue. When the attack is severe, and the galls numerous, they coalesce 

 into patches of various sizes until they cover large areas of the leaf, 

 when the normal action being arrested, the leaf dies and falls to the 

 ground. 



The attack at its commencement is usually slight, but under ordinary 

 conditions it spreads rapidly and proves quite injurious if allowed to 

 continue through the season and for successive years. It seems to be 

 extending from orchard to orchard, and is becoming quite widely dis- 

 tributed, not only in New York but throughout the States generally. 



