WHITE-PINE BLISTER RUST. 63 



THE TELIA AND TELIOSPORES. 



GENERATIONS OF TELIA. 



In 1918 Pennington *' made observations upon the generations of 

 telia at Lewis, N. Y. This was a season very favorable for the 

 occurrence of distinct waves of spore production. The first genera- 

 tion of telia appeared on June 28 with and following the second 

 crop of uredinia. They were present throughout the rest of the 

 season, but in the greatest abundance with and immediately follow- 

 ing a new generation of uredinia. As compared with the uredinia, 

 they were produced in relatively greater abundance with each 

 succeeding generation. There were six distinct waves of teiial 

 production. 



SEASON OP PRODUCTION OF THE TELIA. 



The date when the first telia are produced varies from year to 

 year with the earliness of the season. The earliest of which we have 

 definite record is June 2, 1918, at North Conway, N. H. Table V 

 (p. 72) gives data for the different regions of North America. 

 The telia are formed until the Ribes leaves fall in the autiunn. 

 Drought is likely to cause premature shedding of diseased Ribes 

 leaves soon after the first telia form. This greatly limits the produc- 

 tion of new telia. 



DISTRIBUTION OF THE TELIOSPORES. 



Because the teliospores are produced in more or less compact 

 columellse they are normally 'not separated from the host plant. 

 They do become distributed somewhat, however. Gravatt and 

 Marshall (45) found that slugs eat teiial columns from rusted Ribes 

 leaves; also that sow bugs carry broken columns on their bodies. 

 There seems to be no reason why insects and other animals may not 

 do likewise. 



The teUa are sometimes mechanically broken off and blown about 

 by the wind. 



Diseased Ribes leaves fall to the ground and are blown about by 

 the wind. Often they are broken into small pieces wliich may be 

 blown long distances. In fact, York ^^ found such bits of dead 

 leaves in his spore traps 200 feet distant from the nearest Ribes 

 bush. Telia on dead leaves kept out of doors in the shade are 

 known to retain viability for 65 days, so that in this way the disease 

 might appear in very unexpected places on pines at a greater dis- 

 tance than the sporidia are carried in a viable condition. 



CtERMINATION of the TELIOSPORES. 



The teliospores germinate readily in tap water and produce sporidia 

 in 6 to 12 hours.'*^'^' Each spore produces normally a 4-celled pro- 



" Pennington, L. H. Op. cit. 



«York, H. H. Op. cit. 



« York, H. H., Overholts, L. O., and Taylor, M. W. Op. cit. 



