34 



REPORT 108, U. S. DEPARTMENT OF AGRICULTURE. 



Fig. 42.-Tetranyclius: Genital organs. (Author's illustration.) 



Fig. 43.— Three styles of claws of Ttt- 

 ranychus. (Author's illustration.) 



The genus Acheks (fig. 48) {=SyncaUgus, formerly called Caligonus) lias two 

 described species from the United States-^, conspicuus Berl. and A. cardinalis 



Ewing. The one figured 

 appears to be ^. conspicu- 

 us, or a closely allied form 

 The dorsal surface shows 

 three divisions in front 

 rather indistinctly. They 

 are minute reddish mitea 

 occurring in moss and are 

 not known to spin a thread 



areas. Our two described species are very minute 

 forms and occur singly in moss and are possibly 

 predaceous. 



In Neophyllobius the body is short and the legs 

 are very long; the tarsal joint slightly swollen i^n 

 the middle and ending in two claws. One species, 

 -A^. americanus Banks (fig. 53), occurs on oak leaves 

 in Alabama, and another has been taken in moss in 

 Illinois. In the latter species the tarsus is only 

 very slightly swollen. Tetranychopsis (fig. 51) is 

 known from one species from Canada found on the 

 leaves of basswood. It lives socially after the manner of Tetranyclms 



In Tenmpalpus the palpi are very small and slender and end in two or four short 

 bristles. The species are smaller than Tetranychus and red in color There re 

 several species m our country. Tenuipalpus cali/ornicus Banks (fig. 52) appears to 



be very numerous on the oranges and lemons in 

 California and doubtless causes some injurj*. 

 Inasmuch as it is very small and does not breed 

 very fast, it will probably never be a pest of 

 prime importance. It may be destroyed by 

 the treatment used against ''red spider." T. 

 inornatus Banks occurs on various herbs and 

 bushes in the South. They usually occur in 

 small colonies scattered over the leaves. An- 

 other species occurs on the under surface of 

 grape leaves in the South, the colony usually 

 near the forking of a vein. Still another form*. 

 , . T. cardinalis Banks, has been taken on the 



bark oi ash trees in Arizona. An Etiropean species, T. coronatus Can. and Fanz 

 has been found on jumper trees in Colorado, probably imported, and doubtless many 

 <ither Bpecies await discovery. ^ 



In the genus BryoUa .me species, B. pratcmk Garman (figs. 45, 4G), kn.nvn as tlie 

 clover mite IS very abundant in many localities. In the ^\•cst it is injurimis tl 

 fruit trees. In the Last it more commonly alfects clox-er and annual plants Bryobm 

 usually deposits its eggs on the trunks an,l branches of trees. Sometimes theya o 

 so n„mer,.us, occurring several layers thick, that they give the branches a distinctly 

 ed appearance 1 hey are red, very small and round, and axe often mistaken for 

 the eggs of plant lice. The young hatch early in spring, crawl out on the leaves, and 



Fig. 44.— Tetranychus gloveri: Palpus and 

 mandibular plate. (Author's illustra- 

 tion.) 



