APPENDIX. 367 



THE CLOVER MITE. 



(Bryohia prti/rnxis Garinan.j 



By Prof. C". I,. Maki-.\tt. 

 CHARACTERISTICS AND METHODS OF WOKK. 



The subject of this circular is a reddish-brown mite about twice the size 

 of the ordinary red mite affecting greenhouse plants. It is nearly three- 

 tenths of an inch in length, oval, and with remarkably long anterior legs. 

 Other structural features, together with the peculiar hairs which clothe dif- 

 ferent parts of the body, are illustrated in the accompanying figure, which 

 represents, much enlarged, the full-grown mite, viewed from above and from 

 below. 



This mite first came into prominence as a disagreeable invader of dwelling- 

 houses about ten years since, but it had been known for a number of years 

 earlier as an enemy of various fruit and shade trees and foliage plants, its 

 occurrence on clover, particularly in the middle states, being indicated in 

 its scientific name, p?"a?en.si.'<, and its common name of clover mite. It be- 

 longs to the family of vegetable-feeding mites, Tetranychidte, which includes 

 such well-known depredators as the red spider of greenhouses, already re- 

 ferred to, and the six-spotted mite, which is quite troublesome to oranges in 

 Florida. In California, where this plant mite is especially mischievous, it 

 has been very generally confounded with the red spider, and in probably most 

 of the references to injui-y to deciduous trees on the Pacific Coast by the 

 " red spider" the real culprit is the insect under discussion. 



The presence of this mite on foliage, either of clover or trees, causes the 

 leaves to yellow or assume a sickly appearance, as if attacked by fungus. On 

 the tender leaves of clover, notably on the upper sides, the juices are ex- 

 tracted, often over irregular, winding areas, imitating in appearance the 

 burrows of certain leaf-mining larvae. The most notable indication, how- 

 ever, of the presence of the mite is the occurrence of the eggs, massed often 

 in such numbers as to completely cover the bark at the crotches and branches 

 and sometimes over the entire surface of the trunk. These eggs are of 

 rather large size and of a reddish color, and are conspicuous objects, and 

 when numerous the decided color they impart to the bark leads to their 

 ready discovery. 



As out-of-doors enemies they are injurious at times to clover and other 

 grasses, including the true g-rasses, as bluestem, but it is to fruit trees that 

 their injuries are especially marked. Throughout the Pacific Coast, and in 

 the fruit districts of Colorado and other western mountain states the clover 

 mite is one of the principal enemies of such deciduous fruits as peach, prune, 

 plum, apple, pear, almond, cherry, etc., and the poplar and elm. black locust, 



