14 



explains why, in spite of the great proHficacy of the females, the damage 

 occasioned by the larvae is not greater. 



Upon hatching, the larvae work their way into the soft inner bark, 

 where they feed until their jaws have attained strength enough to attack 

 the harder sap wood, finally reaching the heart wood, where they feed 

 until nearly mature. They seem to prefer the living wood to that which 

 has begun to decay. 



Before maturity the color of the larva is cherry-red, marked with a 

 faint yellowish stripe along the back. After the last molt the bright red 

 color changes to white, with green markings. The head is a tawny yel- 

 low with black mouth parts ; body nearly, cylindrical, somewhat flattened 

 below, with scattered, long, fine hairs. At maturity it measures from^ 

 two to three inches in length by one-half inch in diameter. 



Before changing to the pupa state the larvae bore through the sap 

 wood, or inner bark, and the outer bark except a very thin shell ; they 

 then retire about three or four inches into the burrows, spin their cocoons,, 

 and transform. When ready to emerge, the pupae force their way, by 

 means of -the backward projecting spines on the abdomen, to the mouth 

 of the burrow, where the empty pupa cases may be found hanging from 

 the opening. The pupae are about an inch and three-fourths long by 

 about half an inch thick, and of a dull chestnut color. 



Because of the nature of the work of this pfest, the treatment must be 

 largely preventative. The treatment suggested for the locust borer would 

 probably be as effective here as anything, the only modification necessary 

 being to make the applications during the latter part of June or July, 

 instead of August and September. 



BIBLIOGRAPHY. 



1867, Walsh, Pract. Ent., 2:73. 



1870, Riley, Am. Ent., 2 : 127-128. 



1890, Packard, 5th Rept. U. S. Ent. Comm., pp. 53-58, 373. 



1891, Hopkins, Bui. 16, W. Va. Agri. Exp. Sta., p. 88. 



1893, Hopkins, Bui. 32, W. Va. Agri. Exp. Sta., p. 236, No. 473. 



1894, Hopkins, Bui. 35, W. Va. Agri. Exp. Sta., pp. 291-306. 



1895, Howard, Yearbook U. S. Dept. Agri., p. 379. 



1896, Johnson, 2d Ann. Rept. Pa. Dept. Agri., pp. 353-354. 



1897, Hillman, Bui. 36, Nev. Agri. Exp. Sta., pp. 10-11. 

 1899, Bethune, 30th Ann. Rept. Ent. Soc. Ont., p. 102. 



1899, Luggar, Bui. 61, Minn. Agri. Exp. Sta., pp. 202-204. 



1900, Doten, Bui. 49, Nev. Agri. Exp. Sta., pp. 1-12. 



1904, Hopkins, Bui. 48, Div. Ent. U. S. Dept. Agri., p. 40, No. 247. 



