Kinsey: Studies of Cyfiipidse 



63 



Diplolepis radicum (Osten Sacken) 



FEMALE. — Mesonotum rather smooth; parapsidal grooves lost in 

 rugose areas anteriorly; scutellum without foveae; abdomen wholly 

 smooth; wings largely yellow. HEAD: Somewhat wider than the 

 thorax, hardly enlarged behind the eyes; black, the mouthparts deep 

 rufous, the tips of the mandibles piceous; finely granulose rugose and 

 naked on the vertex and cheeks, roughly rugose and hairy on the face. 

 Antennae short, thick, hairy, black, the first two segments rufous to 

 piceous; with 14 segments, the second segment about globose, the third 

 twice the length of the fourth, the last not half again as long as the 

 preceding. THORAX: Wholly black; mesonotum mostly smoother, 

 shining, sparsely set with short hairs, especially anteriorly, and irregu- 

 larly roughened, in part coriaceous, deeply rugose at the anterior ends 

 of the parapsidal grooves; parapsidal grooves deep, rugose at bottom, 

 almost continuous, lost in the rugose area anteriorly; median groove 

 lacking, short, or discontinuous; anterior parallel lines fine or absent; 

 lateral lines long, fine, and shallow, more or less distinct; scutellum 

 much longer than w^de, roundly pointed posteriorly, very rugose, de- 

 pressed and more rugose anteriorly with a more or less elevated, slightly 

 smoother area extending from the middle of the scutellum anteriorly 

 to divide the anterior depression; pronotum laterally very rugose; meso- 

 pleurag largely smooth and shining, the surface slightly uneven, rugose 

 on the dorsal edge anteriorly, and crossed below the center by a deep, 

 rugose, transverse band. ABDOMEN: Piceous black, more brownish or 

 rufo-piceous basally; entirely smooth and shining, entirely naked except 

 for a very few hairs basally; small, short, considerably produced dor- 

 sally, the second segment covering one-half to three-quarters of the 

 area, the edges of the segments oblique, the hypopygium broad, pointed, 

 the spine short. LEGS: Brownish rufous, the tarsi brighter, the coxae 

 darker basally; tarsal claws moderately heavy, simple. WINGS: Yel- 

 lowish, especially about the radial cell; margins only short ciliate; veins 

 rather fine, of a medium brown; the areolet of a moderate size or large; 

 the cubitus very faint, short, not continuous; radial cell short, broad, 

 open, the second abscissa of the radius sharply bent near the base; the 

 first abscissa arcuate, only suggesting an angle. LENGTH : 3.0-4.0 mm. 



MALE. — Differs from the female as follows: Third segment of the 

 antenna slightly curved; median groove not distinct but discontinuously 

 indicated for some distance; abdomen black, slender, elongate, the sec- 

 ond segment covering hardly two-thirds of the area, edges of seg^nents 

 about vertical; yellow shading on wings not as heavy. 



GALL. — A large, massive, pithy root gall. Polythalamous, larger 

 galls with a hundred or more larval cells. Very irregular in shape, but 

 generally rounded, globular, depressed at the points of attachment, 

 irregularly folded, gTiarled, sometimes as an unopened bud; variable in 

 size, up to 105. mm. in length by 70. mm. in diameter; reddish brown, 

 darkening with age. Internally soft, rather pithy, with only a small 

 amount of woody fiber; the larval cells large, nearly round, often 4. mm. 

 in diameter, with a smooth but hardly distinct, inseparable lining. On 



