20 A REVISION OF THE TYROGLYPHID^. 



Rhizoglyphus phylloxerse Riley. (PI. VI, fijj'. 61.) 



Cephalothorax with a pair of frontal bristles and a pair of much 

 larger posterior bristles, also a pair of minute intermediate bristles; 

 one bristle on each humerus; in the female there are six short bristles 

 near the tip of the abdomen, the longest pair not one-half the width 

 of the body; a submedian pair of short ones behind the middle of the 

 dorsum, and one short bristle on each posterior side. The male has 

 eight bristles at tip of abdomen, some about as long- as width of body; 

 while the dimorphic male with the thickened leg III (PI. VI, tig. 60) 

 has these apical bristles about as long as the abdomen, and two 

 pairs of long bristles on the dorsum. The legs are rather long; 

 tarsus I (PI. VI, fig. 59) has no spine above near the sense hair, but 

 toward the middle is a stiff bristle; the other spines are present and 

 are long, the apical hairs are shorter than the joint; the bristle from 

 the penultimate joint is longer than the tarsus in all except the hind 

 legs; tarsus IV (PI. VI, fig. 57) is about as long as two preceding- 

 joints together, and in the male is still more elongate; it has two spines 

 below near middle; the apical hairs are shorter than the joint. The 

 enlarged leg III of the dimorphic male ends in a long claw; several 

 bristles are near by, but no tooth. In life these mites are rather 

 yellowish white, with chestnut-brown legs and a dark spot on each 

 posterior side of the abdomen. 



Length 0.75 to 1 mm. 



I identif}^ this with Riley's species, since his figures of the legs show 

 a rather slender tarsus, and the other characters shown bv his figure 

 agree with this form. 



Specimens have been examined from the roots of cowpeas from 

 Macon, Ga.; from Auburn, Ky., on sca1)by potatoes: from Lawrence, 

 Mass., on young potato plants, and from Akron, Ohio, on rotten 

 potatoes; also from Illinois, infesting pine cones. 



Michael has considered that Riley's species w^as a synonym of 

 R. echinopv.s Megn. {hyaeinfh! Boisd.). This species is, however, 

 abundantly distinct from the ''bulb mite," and perhaps does not now 

 occur in Europe, altho it was introduced into France. At that time 

 it was supposed to feed on the Phylloxera. 

 Rhizoglyphus tarsalis n. sp. 



This species is similar in nearly all respects to B. phyUo^ceree; that 

 is, there is no spuie on tarsus I (PI. V, fig. 45) near the sense hair, 

 and the tarsi are long. I have not seen any males, but the female 

 differs from R. plinUoxevce in having the liristles near tip of abdomen 

 nearly as long as width of body, and in the plainly longer hind tarsi 

 (PI. V, fig. 4B), which are longer than the preceding two joints 

 together. 



The specimens come from Spreckels, (Jal., taken from sugar beets 

 by Mr. E. S. G.Titus. 



