CORNELL UNIVERSITY EXPERIMENT STATION BULLETINS. 253 



cooler lands from Mew England to North Carolina and Minnesota. It is 

 in cultivation as an ornamental plant under the name of Primus pumila. 

 (c) The representative of P. pumila upon the plains of Nebraska and in 

 the Eocky mountains is a very low plant with short thick leaves and large 

 short-stemmed fruit, the botanical position of which is yet unknown. It 

 is now in cultivation as the Improved Dwarf Rocky Mountain cherry. 



29. The Utah Hybrid cherry is a fruit of uncertain value and doubtful 

 affinity. Two varieties, the black and red, are in cultivation. It probably 

 comes from some part of the western plains or the Rocky mountain region, 

 but its wild prototype is not known. 



30. Other native cherries in cultivation are: Primus serotina, the Wild 

 Black cherry; P. Pemisylvanica; the Bird, Pin, or Wild Red cherry; P. 

 Virginiana, the Choke cherry; P. demissa, the Western Choke cherry; 

 P. ilicifolia, the Islay of the Pacific slope; P. CaroUniana, Cherry- 

 Laurel or Mock Orange of the southern states. 



L. H. Bailey. 



THE PEAR TREE P8TLLA. 



The pear tree has heretofore suffered less from the attacks of insects 

 than other extensively grown fruits like the apple, plum, and others. 

 Recently, however, a minute insect known as the pear-tree psylla, Psylht 

 pyricola, has inflicted such severe losses upon pear-growers that it threat- 

 ens to seriously interfere with the successful cultivation of this fruit. 



During 1891, pear-growers, in restricted localities in quite widely sepa- 

 rated portions of this and of neighboring states, lost thousands of dollars' 

 worth of fruit and many valuable trees through the ravages of this pest 

 which suddenly appeared in enormous numbers early in the season. The 

 pear orchard of Dr. Jabez Fisher, Fitchburg, Mass., was seriously injured; 

 CoE Brothers. Meriden, Conn., had two orchards devastated by the pest. 

 In New York state, orchards in the eastern, central, and western portions 

 suffered. On West Hill, near Ithaca, Tompkins county, several orchards 

 were severely attacked, some of the trees ultimately dying; Mr. H. S. 

 Weight's orchard promised six hundred bushels of fruit, but less than 

 fifty bushels matured, and but few trees made any growth. A severe attack 

 prevailed at Menands, Albany county. Mr. G. T. Powell, an extensive 

 fruitgrower in Ghent, Columbia county, states that the insects reduced 

 his pear crop from an estimated yield of twelve hundred barrels to an 

 actual yield of less than one hundred barrels of marketable fruit; the trees 

 made but little growth and several were killed; his trees have been notice- 

 ably losing vitality for two or three years, due, no doubt, to the unsus- 



