47 



In the following brief review of our notes and observations relating 

 to this mite we have preferred to associate by localitiesall references to 

 it, rather than to adopt a chronological arrangement. From these notes 

 a good knowledge of its distribution and habits may be obtained, the 

 entomologist having personally observed itnot only at Washington but 

 at many points in the Mississi^ipi Valley, as far as St. Louis, where it 

 is quite common, and also in California. 



Distribution. — The first reference to the occurrence of this mite 

 at Washington bears date of March 21, 1879, when the eggs and 

 young together with adult mites were found abundantly on the twigs 

 and bark of the elms in the Department grounds. On May 9 of the 

 same year, it was found to infest the leaves of the red clover in great 

 numbers throughout the city of Washington. The clover leaves, espe- 

 cially the older ones, had a sickly appearance as if attacked by a fungus ; 

 the younger leaves showed very clearly, however, that this appearance 

 was caused by some species of insect, and at first sight seemed to be the 

 the work of a microlepidopterous leaf-miner, but closer inspection 

 showed it to be the work of a mite, of which quite a number were found 

 on the leaves, chiefly on the upper sides, where they extracted the juices 

 as they slowly crawled along, leaving behind them a discolored narrow 

 line of irregular windings which imitated to perfection the mines of 

 certain Tineidce. 



In December of the same year, also, eggs, which afterwards proved 

 to belong to this species, were found very commonly on the bark of 

 apple trees in the Department orchard. 



Since 1879 these mites have been observed every spring and summer, 

 chiefly on clover, but also on various trees, notably Apple, Elm, and 

 Peach ; and in the fall and winter, on or beneath the bark and at the 

 angles of the branches of trees, occurring in connection with numerous 

 eggs and young in various stages of development. The mites and eggs 

 occur on all rough-barked trees examined in the grounds of the Depart- 

 ment, and particularly on Apple, Elm, Arbor-vitae, and Black Locust. 

 Their blood-red eggs have frequently been observed in numbers suf- 

 ficient to impart a reddish color to the trunks and branches of the in- 

 fested trees. 



In the Eastern States but one account of its infesting houses has 

 been brought to our notice. Mr. George N. Kimball, of Waltham, Mass., 

 writes, sending specimens, under date of May 24, 1884, as follows : 



We have occupied the house in which the inclosed mites were obtained but for a 

 few weeks and do not know how long they may have been about * * * Tht^ 

 mites have not been found iu auy of the rooms except the sitting-room and parlor, 

 but are quite numerous under the bay windows of these rooms. A few are also found 

 under other windows and on the mop-boards. 



In the central States the incoQvenience occasioned by their presence 

 in houses has been more frequently reported, as the following refer- 

 ences show : 



