No. 2303. RED SPIDERS OF A2IEIlICA—2IcGREGOR. 671 



PAKATETR.4NYCHUS PILOSLS (Canestrini and Fanzago). 



Plate 79, %. 14. 



Tetranychics pilosus Canestrini and Fanzago, 1877-78, Intorno agli Acari 

 Italian!, Atti 1st. Venet., ser. 5, vol. 4, pp. fi9-208. 



Canestrini and Fanzago (3) in 1878 referred this species to the 

 genus Tetravychus, but Zacher (13), in 1910, as before mentioned, 

 erected the genus Paratetranyehus to include P. wnunguis Jacobi 

 and P. pilosus. P. pilosus is called the rose mite in Italy and occurs 

 there most commonly on roses, Rihes, species, pear, and cherry. 



Length of female, 0.315 mm. Dorsal bristles, 26, in four rows, 

 line-pointed, pilose, and arising from tubercles. Palpal "thumb" 

 bears on its tip a stout spatulate ' 'finger, " the thickness of which 

 about equals its length. The usual dorso- terminal digituii, the dorsal 

 "finger" which is tack-like, and the dorso-basal hairs occur on the 

 "thumb," as well as the latero- ventral hair. The tarsus possesses 

 a heavy, sickle-shaped claw wliich is thickest at mid-point; from this 

 middle point ventrally four appendiculate spurs arise which con- 

 siderably surpass the claw. The usual four tenent hairs are present. 

 The inner lobe of the penis (see pi. 79, fig. 14) is club-shaped, thick- 

 ening considerably posteriorly to form the obtuse basilar lobe; the 

 shaft barely half as long as inner lobe but otherwise similar; hook 

 bent only 45° from the main axis of the penis, sharply acuminate 

 without barb. Collar trachea straight and of even caliber, with 

 spherical, dilated chamber. Mandibular plate narrowed and rounded 

 anteriorly, but not emarginate. 



PARATETRANYCHUS VIRIDIS (Banks). 



Tetranychus viridis Banks, 1894, Trans. Amer. Entom. yoc, vol. 21, p. 218. 

 Tetranychus simplex Banks, 1914, Pomona Journ. Ent. Zool., vol. 6, no. 2, p. 57. 



Banks's (8) description of P. viridis, which 

 follows, is in the most abstract terms and in 

 no way differentiates the species from the red 

 spiders : 



Length, 0.40 mm. Greenish, with a large, blackish or 

 sometimes reddish spot each side covering the shoulders 

 of the alidomen and the posterior angles of the cephalo- 

 thorax. The cephalothorax is quite distinctly sepa- 

 rated from the abdomen by a constriction; the abdomen 



broadest at the shoulders ; the cephalothorax short, broadly ^la- (».— Pak vtetranychus 

 rounded. The body bears a few long bristles. Those ''''^'^''^ "''''''• ^\ ^""^-'^ 

 on the legs are similar, but shorter. The anterior 

 pairs of legs are somewhat larger than the posterior agks (okicix.vl). 

 pairs. 



A critical study of Banks's material reveals the following tarsal 

 and palpal characters: 



,vp pen a g e s ; ■>, palpal 

 thumh" and its APPKND- 



