290 JOURNAL OF ECONOMIC ENTOMOLOGY [Vol. 5 



THE CLOVER MITE 



Bryohia pratensis Garman 

 By F. M. Webster, Bureau of Entomology 



In preparing circular No. 158 treating upon this species the writer 

 found such a vohiminous record of its occurrence and habits through- 

 out the country as to render the information unavailable for that 

 particular publication. 



Nevertheless, there is some ground for the criticism of an author 

 who publishes on a species Avithout giving all of the facts in his pos- 

 session. The situation is usually brought to the front by other writers 

 in after years publishing as new what was already known, but the 

 facts locked up in the unpublished records of some individual or 

 institution. 



It has therefore been thought advisable to publish elsewhere the 

 records of the Bureau of Entomology bearing upon this mite. 



On December 5, 1878, eggs that afterwards hatched young of this 

 mite were found on the branches of elm, especially about the forks, 

 in the city of Washington, D. C, by Mr. Theo. Pergande, of the 

 Bureau of Entomology. The young mites hatched January 18, 1879, 

 and belong to this species, as afterwards described. 



March 8, 1879, there were received from Mr. Charles Fremd, 

 Rye, N. Y., eggs which he found in large numbers on his peach trees 

 and on grapevines in his neighborhood. Young mites of this species 

 were reared from these eggs. 



March 21, 1879, full-grown mites were found on elm, also in Wash- 

 ington, and eggs collected at the time developed mites three days 

 later. Full-grown adults were also found on elm in the city on 

 March 24. 



On May 6, 1879, six years prior to publication of the description, 

 Mr. Pergande discovered the mite injuring clover on the grounds of 

 the Department of Agriculture and elsewhere about Washington, D. C. 

 This injury Avas described at the time as giving the leaves of clover, 

 especially the larger and older ones, a diseased appearance, as if at- 

 tacked by a microscopic fungus. The j^ounger leaves indicated very 

 clearly that this appearance was caused by the feeding of this mite, 

 principally on the upper surface. As they slowly crawled along on 

 the leaf they were observed to leave behind them not only a very 

 fine silky web, but also a discolored narrow line winding irregularly 

 about and imitating to perfection the mines produced by some of 

 the microlepidopterous leaf-mining larvae. 



