Report of the State Entomologist. 235 



Mytilaspis poyyiicorticis Eiley: 5th Kept. Ins. Mo., 1873, pp. 73-96, figs. 

 31-34 (extended general account); in Amer. EntomoL, iii, 1880, p. 

 107 (from Alabama); in Bull. 6, U. S. Ent. Comm., 1881, pp. 85, 86 

 (description); in Scientif. Amer., xlvi, 1882, p. 335, figs. ; in Eept. 

 Comm. Agricul. for 1884, p. 353 (distrib. by birds). 



Aspidiotus conchiformis. Lintnee : in Count. Gent., xlii, 1877, p. 69. 



Mijtilaspis pomorum. Comstock : in Eept. Comm. Agricul. for 1880, pp. 

 325, 326, pi. 19, flg. 2 (descr. and food-plants); 2d Eept. Dept. 

 Entomol.— Cornell Univ. Exper. Stat., 1883, pp. 118-121, pi. 2, figs, 

 5, 5a. 



Mijtilaspis pomorum. Cook, M. : in Eept. Comm. Agricul. for 1881, p. 208 

 (resistance to insecticides). 



Mytilaspis pomorum. Saunders : Ins. Inj. Fruits, 1883, pp. 40-44, figs. 28-34 

 (nat. hist., remedies, etc.). 



Mytilaspis pomorum. Lintner: in Count. Gent., xlviii, 1883, p. 801 (on wil- 

 lows) ; id. li, 1886, p. 469 ; id. Iii, 1887, p. 321. 



Mijtilaspis pomorum. Hubbard : Orange Insects, 1885, p. 15, figs. 1, 2 (show- 

 ing growth of scale). 



Mytilaspis pomorum. Packard : Entomol. for Begin., 1888, p. 79 (mention). 



A Common and Pernicious Apple Tree Pest. 



The scales of this insect upon apple tree bark were sent from 

 Genesee county, N. T., with the statement of its recent introduction 

 in that vicinity, and the request for information of its nature — how it 

 spreads from tree to tree, whether the infested trees should be 

 destroyed, or if it were possible to arrest the attack. 



The scales completely covered the piece of the branch that con- 

 tained them. Similar examples had been received from time to time, 

 for name and information, from different parts of the State of New 

 York and other States, showing a quite general distribution of this 

 pest of the apple tree — one of the most injurious of the large number 

 that infests it. So common have they become in our orchards, and 

 so destructive to the trees of which they take possession, killing- 

 large numbers of them, that they should be known by all of our 



apple growers. 



Its Rapidity of Increase. 



When this scale has been allowed to propagate itself for a few 

 successive years without eiSort made to destroy it, the individuals 

 become crowded together upon the trunk, limbs, and twigs of the 

 tree as thickly as they can place themselves — forcing one another out 

 of position and frequently overlying, and continuing to add to their 

 number so long as they are able to reach with their proboscis the 

 bark and the sap beneath. 



A correspondent, writing from Newburgh, N. T., thus describes the 

 progress of an attack : " Immediately after the fastening of the scale, 



