450 Report of the Horticulturist of the 



crimson discoloration of tlie sapwood and fruit. It multiplies 

 with great rapidity. In examining a tree for this insect the 

 trunk and larger limbs and the fruit should receive an especially 

 close scrutiny as the scales are often found here in large num- 

 bers when only scattering on the smaller limbs. 



Treatment. — The treatment of this insect is a matter of so great 

 importance that it will be made the subject of a separate bulletin. 

 Where it has once become firmly established it probably cannot 

 be exterminated. When recently introduced it has in some cases 

 been exterminated by burning the infested trees, or by thorough 

 treatment with whale-oil soap at the rate of two^ pounds to a 

 gallon of water, or by both. The most effective known method 

 of treatment is fumigation with hydrocyanic acid gas. The use 

 of kerosene and water or crude petroleum is still in the experi- 

 mental stage and cannot as yet be recommended for general use. 



SCURFY BARK-LOUSE. 



(Chionapsis furfurus Fitch.) 



Description. — This insect sometimes occurs in large numbers 

 upon young pear trees. The scales are a dirty white color, 

 broadly wedge shape in outline and vary in length from about 

 one-sixteenth to nearly one-eighth of an inch. 



The life history of this species is very similar to that of the 

 oyster-shell bark-louse; with both species the eggs are retained 

 under the parent scale during the winter. The eggs vary greatly 

 in number, from ten or twelve upwards, as many as seventy-five 

 having been found under a single female scale. They hatch from 

 the first to the middle of May. There is probably but one brood 

 annually. The male scale is much smaller than the female, is 

 elongate, with nearly parallel sides and is a clearer white color. 

 The adult male is a delicate two winged insect. 



Treatment. — The treatment for this insect is the same as for 

 the oyster-shell bark-louse. See page 417. 



