1911] Ewing — Predaceous and Parasitic Acarina 37 



NEW PREDACEOUS AND PARASITIC ACARINA. 



By H. E. Ewing. 

 Ithaca, N. Y. 



The new species of mites here described will nearly all be 

 treated of more fully later. In this paper are included the de- 

 scriptions of two species which have a prime economic importance, 

 as they are two of the few species of mites which are largely 

 responsible for holding in check the oyster shell and other scales. 

 These forms, one a species of Tydeus, the other a Tarsonemus, 

 were studied by the writer while working at the Iowa Experi- 

 ment Station last summer, and will be treated of fully later by 

 Mr. R. L. Webster in a special bulletin upon the oyster shell 

 scale. 



Another of the mites described is very interesting on account 

 of both its scientific and economic importance. It is a new spe- 

 cies of the genus Stigma>odes, and the first of this genus to be 

 found in North America. The members of this genus are long 

 drawn out, and have the body strongly constricted at the middle 

 which causes them to resemble strongly a pair of twins which have 

 been born attached to each other. This species was sent in 

 by Mr. S. A. Johnson from the Colorado Experiment Station, 

 where it is very abundant. It belongs to the group called the 

 "Red Spiders" which are so notorious for their attacks upon 

 greenhouse plants and shade trees, and is a species which de- 

 serves careful watching as it is liable to take up habits similar 

 to the others of its group and cause serious damage to culti- 

 vated plants. 



Two species of Analgesidce, "Bird Mites," are described. One 

 of these, an Alloptes was sent to me this last summer from the 

 Bermuda Islands by Mr. A. O. Gross, who obtained the specimens 

 in great quantities from a tropical bird. 



Complete illustrations of most of these species will be pub- 

 lished soon in a paper by the author on the "Phylogeny and 

 Distribution of the Parasitic Acarina." 



