BEDEGUAR 



527 



kins developing the most quickly ; those forming on young leaves 

 also grow with rapidity, while galls formed on bark or roots may 

 take months to attain their full size. 



It is a curious fact that Cynipid galls are formed chiefly on 

 oaks, this kind of tree supplying a surprising number and variety 

 of galls. The plants that furnish Cynipid galls in Europe are 

 not numerous. A list of them is given by Cameron. 1 Several 

 species, of the genus Hhodites, attack rose-bushes. One of the 

 best known of our British galls is the bedeguar, found in various 

 parts of the country on both wild and cultivated rose-bushes (Fig. 

 348), and caused by Rliodites rosae (Fig. 349). This gall has 



FIG. 348. Bedeguar 

 on rose, cut across 

 to show the cells 

 of the larvae ; in 

 some of the cells 

 larvae are seen. 



the appearance of arising from a twig or stem, but it is really a 

 leaf gall. Pazlavsky 2 has described the mode of formation of 

 the bedeguar. The female Ehodites in the spring selects a rose- 

 bud not a flower-bud that should produce a twig and leaves, 

 and pricks this bud in a systematic manner in three places. The 

 three spots of the bud pricked by the Insect are the three unde- 

 veloped leaves that correspond to a complete cycle in the phyllo- 

 taxis of the plant. The three rudiments do not develop 

 into leaves, but by a changed mode of growth give rise to the 

 bedeguar. Usually this gall, as shown in our figure, is of 

 large size, and contains numerous cells ; but abortive specimens 

 are not infrequently met with ; sometimes a small one is seated 

 on a rose-leaf, and it is thought that these are due to a failure 

 on the part of the Insect to complete the pricking operation. 



1 Ray Soc. vol. iv. 1893, p. 24. 

 2 Term. Fuzetck, v. 1882, p. 198, and Biol. Centralbl. ii. 1882, p. 617. 



