DISEASES OF THE ROSE. 195 



pass the winter in a chrysalis state. The bedeguars were form- 

 erly employed in medicine as astringents. The male cynips is 

 distinguished by the absence of a tail. 



16. CvNirs BicoLOR. — " Round, prickly galls, of a reddish color, and 



rather larger than a pea, may often be seen on rose-bushes. Each 

 of them contains a single grub, and this in due time turns to a 

 gall-fly. Its head and thorax are black, and rough with numer- 

 ous little pits ; its hind-body is polished, and, with the legs, of a 

 brownish red color. It is a large insect compared with the size 

 of its gall, measuring nearly 'one-fifth of an inch in length, while 

 the diameter of its gall, not including the prickles, rarely exceeds 

 three-tenths of an inch. 



17. " Cynjps dichlocerus, or the gall-fly with two-colored antennae, is 



of a brownish red or cinnamon color, with four little longitudinal 

 grooves on the top of the thorax, the lower part of the antennae 

 red, and the remainder black. It varies in being darker some- 

 times, and measures from one-eighth to three-sixteenths of an 

 inch in length. Great numbers of these gall-flies are bred in the 

 irregular woody galls, or long execresences, of the stems of rose- 

 bushes. 



18. Cynips semipiceus. — " The small roots of rose-bushes, and of other 



plants of the same family, sometimes produce rounded, warty, 

 and woody knobs, inhabited by numerous gall-insects, which, in 

 coming out, pierce them with small holes on all sides. The 

 winged insects closely resemble the dark varieties of the preced- 

 ing species in color, and in the little furrows on the thorax ; but 

 their legs are rather paler, and they do not measure more than 

 one-tenth of an inch in length. 



19. Selandria Ros/e. — " The saw-fly of the rose, which, as it does not 



seem to have been described before, may be called Selandria Bosce, 

 from its favorite plant, so nearly resembles the slug-worm saw-fly 

 as not to be distinguished therefrom except by a practised ob- 

 server. It is also very much like Selandria barda, Vitis, and 

 fygmcea^ but has not the red thorax of these three closely al- 

 lied species. It is of a deep and shining black color. The 

 first two jjp-irs of legs are brownish gray or dirty white, except 

 the thighs which are almost entirely black. The hind-legs are 

 black, with whitish knees. The wings are smoky, and transpa- 

 rent, with dark brown veins, and a brown spot near the middle 

 of the edge of the first pair. The body of the male is a little 

 more than three-twentieths of an inch long, that of the female 



