[139] 



Report of the State Entomologist. 



281 



of the plum." He writes: "It would seem to follow that there are 

 three distinct black-knots, originating, respectively, from choke- 

 cherry, from the common wild plum and from the Chickasaw plum." 

 (American Entomologist, ii, 1870, p. 231.) 



Those who have studied this fungus the most thoroughly believe 

 in the existence of but one species, which readily transfers itself from 

 the plum to the cherry, and the reverse. According to Professor Peck, 

 New York State Botanist, "it is now known to occur on Prunus 

 dome8tica, P. Americana, P. cerasus, P. Virginiana, P. Pennsylvania, and 

 P. serotina. Two of these are plum trees — one introduced, the other 

 native — and the remaining four are cherry trees, of which the last 

 three are indigenous" (Thirty-first Report of the N. Y. State Museum 

 of Natural History, 1879, p. 60*). 



Remedy. 



The only remedy, so far as known, for the black-knot, is the free use 

 of the knife as early as possible after its discovery. Mr. Walsh has 

 emphasized the following as the remedy that may be relied on: 

 "If the diseased twigs are cut off and destroyed early in July in the 

 latitude of New York, or a little earlier or later according to the lati- 

 tude, taking care to cut a few inches below the affected part, the 

 black-knot can be checked and probably entirely eradicated; but if this 

 operation is delayed until August, it will be of no benefit whatever." 



If the above remedy is resorted to in the early stage of growth the 

 limb or twig need not be removed, but the fungus can be cut out 

 with a sharp knife while still confined to one side of the branch, 

 permitting, if properly done, the wound to heal in a short time. 



Those who experience difficulty in arresting the spread of the 

 black-knot should avail themselves of the information contained in a 

 paper entitled " Black-knot — Cause and Remedy," by Professor C. H. 

 Peck, published in the Country Gentleman for June 28, 1888 (vol. liii, 

 page 485). No paper of higher practical value has ever been pub- 

 lished on the subject. 



Collections in the Adirondack Region, et al. 

 [From the Report of the Entomologist to the Regents of the University for 1883, 

 published in the Thirty-seventh Annual Report of the New York State Museum of 

 Natural History.] 



The collections [for the year 1883] have mainly been made in Mid- 

 dleburgh, Schoharie county; at Elk lake, in Essex county; in the town 

 of Hammond, St. Lawrence county; and in Albany. 



*In addition to the species herein named, I have also observed it abundantly on the 

 sand plum, Prunus maratima, on Coney Island. 



36 



