334 REPORT OF THE COMMISSIONER OF AGRICULTURE. 



pound to 1 gallon, adding sulphur, but has "more scales than ever." 

 He wrote to parties whom he heard were successful, and learned that 

 "no one had met with any better success." One man used 2 pounds 

 American concentrated lye to 1 gallon. The application "killed some 

 of the small limbs, and cracked the bark on the trunks of the largest 

 trees, and on some of those trees where he used the strong solution he 

 finds plenty of scale bugs yet." He had expended last year $900. 



No one can doubt that such powerfully caustic applications as the 

 above will kill scale insects if properly applied. The fact that auy in- 

 sect escaped an application of 2 pounds concentrated lye to 1 gallon 

 of water shows that the aid of a good spray-nozzle is quite as impor- 

 tant as the use of a good insecticide. In the experiments recorded 

 above, had use been made of the "cyclone" or "eddy jet" nozzle, de- 

 scribed in the two last annual reports from this Bureau, while the in- 

 jury to the plant might not have been less, the insects at least would 

 have been exterminated. 



Our California correspondence shows also, as we foretold would be 

 the case, that the kerosene emulsion is making headway in spite of 

 previous prejudice. 



MISCELLANEOUS INSECTS. 



THE AMEBIC AN CIMBEX. 

 (Gimbex americana Leach.) 

 Order Hymenopetra; Family Tenthredindd^. 

 [Plate Y, Fig. 1.] 



INJURY TO WILLOTTS; A NEW HABIT. 



During the latter part of May last, Admiral Ammen, who is noted in 

 Washington for his devotion to horticulture and arboriculture, brought 

 us specimens of this large saw-fly, with an account of its injuries to his 

 imported willows, not as usual by the larva, but by the gnawing of the 

 perfect fly, the plantation being described as looking as if a fire had 

 run over it, or as if it had suffered by a severe frost. As this habit was 

 new, so far as we have any records, and as nothing was known of the 

 mode of oviposition in the species, we had the matter investigated^ 

 The tips of many of the plants were found to be dark-brown and dead; 

 the dried-up portion extended 2 to 4 inches from the tip. Upon inves- 

 tigation it was plain that the cause of the trouble was a very fine but 

 deep transverse incision just below the dead portion of the willow, the 

 incision often extending more than half way around the twig, or there 

 being a number of smaller incisions, one above the other. (PI. Y, Fig. 

 1, b.) All these incisions were so narrow that they Could hardly be 

 supposed to have been made for feeding purposes ; but in many in- 

 stances a number of larger marks — usually of an oblong shape — were 

 visible, and looked as though they had been made for food. 



According to Admiral Ammen this injury was done by the saw-flies 

 in the latter part of May; but on the 5th of June the flies had for the 

 most part disappeared, and Mr. Schwarz, who made examination after 



