1861 . 
I 
GrOUREAU, Ch.— Le Petit-Rongeur du Pommier ( Scolytus rugu- 
losus, Ratz.) (Les Insectes Nuisibles aux Arbres fruitiers, 
1 etc., p. 22.) 
Frequently attacks old apple-trees and even young ones of 
languid growth, causing the twigs to die and dry up until the 
fcree-top may be crowned or surrounded by dry branchlets. 
New shoots spring out to take the place of those killed, with 
the effect to hasten the death of the upper branches. These 
sprouts are then attacked in turn, the malady killing the tree 
after two or three years. Appearance of injured branches and 
■the work of the beetle described in detail. 
Larvae get their growth by beginning of winter, pupate the 
; last of May, and mature in June. Beetle and larva and two 
parasites ( Bl&cus fuscipos and Pteroni&lus biniciculcitus ) de¬ 
scribed. 
Must be opposed by maintaining the vigor of the tree. Ap¬ 
pears to have for its'natural mission the destruction of sick or 
feeble trees or branches, but still may be injurious to man, like 
many other insects whose function is beneficial to nature at 
large. 
1862. 
■ 
Dobner, E. Ph.— Handbuch der Zoologie, II., p. 164. 
Briefly described. Found in plum, cherry, apple, and quince 
and also in dry branches of mountain ash. Trunks and 
branches die, and beetle may consequently become noticeably 
injurious. 
1867. 
Boisduval, Jean Alphonse. —Essai de 1 Entomologie Horticole, 
p. 162. 
The author describes injuries of Scolytidee in general, giving 
it as his own judgment, after long study, that the ‘‘effect has 
been mistaken for the cause;’’ or, in other words, that 
trees are attacked by Scolytidse only because they are 
already diseased, and that it is absolutely necessary to the 
propagation of these borers that the bark and the cambium 
should have undergone some morbid alteration. Quotes cor¬ 
roborating opinions and describes illustrative instances. Refers 
to S. rugulosus as occurring often under the bark of “old dis¬ 
eased fruit-trees." 
1872. 
Kaltenbach, J. H. — Die Pflanzen-Feinde aus der Classe der 
Insecten, p. 154. 
Brief observations on injuries and life history. 
