72 



BtJLLETlN &57, TJ. S. DEPART'MEjSTT OF AGRICULTURE. 



IMPORTANT DATES IN THE LIFE fflSTORY OF CRONARTIUM RIBiCOLA. 



Table V shows some of the more important dates in the develop- 

 ment of the white-pine blister rust and their variation according to 

 locality. These dates are rarely the earliest or latest possible ones, 

 but are based upon notes actually made respecting the point covered. 

 It is hoped to extend this table greatly and approach nearer the 

 actual date when each stage of development is reached by the fungus 

 in the various regions. Southern New England is here made to 

 include Massachusetts, Connecticut, and Ehode Island. Northern 

 New York is understood to include approximately that part of the 

 State lying north of a line between Glens Falls and Oswego. The 

 Lake States include Michigan, Wisconsin, and Minnesota. Similar 

 data for Europe are given in the last columns of the table for the 

 sake of comparison. 



Table V. — Important dates in the life history of Cronartium ribicola, as observed in 



America and in Europe. o- 



[To economize space, the century digits 19 are omitted in noting the year of each observation; thus 



'09= 1909.] 



Development 

 noted. 



United States. 



Southern 



New 

 England. 



Southern 

 New York, 

 New Jersey, 

 and eastern 



Pennsyl- 



Northern 



New 

 England. 



Northern 

 New York. 



Lake States, 



Europe. 



Date. 



Loeal- 



ity.b 



First closed blis- 

 ters 



Apr. 7, '17 

 Apr. 5/18 



Apr. 30, '11 

 Apr. 28, '17 



May 4, '18 



Apr. 15, '10 Apr. 26, '18 

 Apr. 7, '17 Apr. 21, '19 

 May 13,'18 {.... 



May 5, '17 

 Apr. 19, '18 

 Apr. 18, '19 



First open blis- 

 ters 



June 22, 

 May 22, 

 May 16, 

 June 3, 

 May 25, 

 June 2, 

 May 3, 

 Apr. 17, 

 Apr. 7, 

 Mar. 28, 



June 1, '09 

 July 27, '10 

 May 5, '11 

 June 10, '13 

 May 20, '15 

 Apr. 7, '16 

 Apr. 28, '17 

 May 16, '18 



Last yellow blis- 

 ters 



June 14, '09 

 May 26, '10 

 June 9, '11 

 May 15, '12 

 June 6, '13 

 May 15, '15 

 May 15, '16 

 Apr. 29, '17 

 Apr. 23, '18 

 Apr. 7, '19 



June 7, '10 

 July 1, '17 

 July 21, '18 



First uredinia 



First telia . 



June 3, '16 

 June 13, '17 

 May 29, '18 



June 10, '13 

 July 18, '16 



June 17, '16 

 July 21, '17 

 June 19, '18 

 July 30, '19 



First pycnialf 

 drops \ 



June 21, '16 

 June 7, '18 



July 24, '13 

 July 14, '14 

 May 20, '17 

 May 16, '18 

 May 23, '19 



June 26, '13 

 July 24, '16 

 June 10, '17 

 June 2, '18 

 June 6, '19 



July 26, '13 

 June 7, '18 



June 8, '09 

 May 12, '10 

 Apr. 26, 'IS 

 Apr. 23, '19 



June 12, '18 

 June 26, '19 



July 25, '09 

 July 18, '16 

 June 28, '17 

 May 16, '18 

 May 23, '19 



Aug. 23, '17 

 June 26, '18 

 June 30, '19 



July 3, '18 

 June 26, '19 



May 24, '16 

 May 8, '17 

 Apr. 19, '18 

 Apr. 22, '19 



Apr. 16, '90 

 Apr. 15, '01 

 Apr. 7, '09 

 Mar. 17, '18 



JApr. 15, '90 



Apr. 29, '96 

 Apr. 28, '08 



June 24, '17 

 June 24, '19 

 Sept.l6,'19> 



June 9, '16 

 June 12, '17 

 May 18, '18 

 June 5, '19 



May 15 



May 9 



June 1 



May 19, '18 



May 23 



May30 



May 26 



June 2, '19 



July 21, '16 

 June 12, '17 

 July 8, '18 

 July 10, '19 



Aug. 1.. 

 ^ July 30. 



H 



M 

 D 

 F 



H 



Bo 



S 



B 



H 



D 



Bo 



F 



D 

 B 

 B 



S 



o Notations for Ontario, Canada: First open blisters — May 10, 1917, and June 22, 1918; first uredinia — 

 June 24, 1915, and July 20, 1916; first telia— June 24, 1915. 



b Abbreviations used: B=Berlia, Bo= Bohemia, D= Denmark, F= France, H= Hamburg, M= Mu- 

 nich, S= Silesia. 



c This date is an extraordinarily late one for aecia to be formed, but it is included here to show the possi- 

 bility of the secial season being prolonged throughout the summer. 



