MOTH CATERPILLARS AND PLANT-LICE. 



59 



Fio. II. Piitodei ttrobi: beetle at left; a, 

 larva; 6, pupa enlarged about three 

 times (from Packard). 



spots, as shown in the accompanying illustration (fig. 11). It is provided with a rather long 



rostrum or suout to which are attached its elbowed antennre. The larva, which is white aud foot- 



less, is illustrated at a, and the pupa, also white, is figured at 6. 



This weevil is one of the first spring visitants in the North, occurring as early as March abont 



Washington City and in April or May farther north. Its eggs are deposited on the terminal shoots 



of pine, particularly of young trees, but sometimes also in the bark of old trees. The larva, when 



hatched, bores into the pith or mines the sapwood. Toward the 



end of summer it attains full growth, when it goes into hiberna- 



tion until the next spring, transforming to pupa and soon after- 



ward to the mature or beetle form. The presence of this insect in 



a tree is first manifested by the wilting of the leading shoots, which 



becomes most evident toward the close of summer. The identity 



of the species at work may be established at once from its peculiar 



cells beneath the bark. (See fig. 12.) These cells, which are 



destined for its winter nest and for further transformation, are 



sunk into the pith and covered over with long fibers of chipped 



wood. When a terminal shoot of a small tree becomes filled in the summer with these larvaj, to 



the number sometimes of a score or more, the shoot, with its lateral branches, as well as the stock 



below, wilt and gradually die, the bark becomes loosened, pitch oozes out, and by autumn the 



shoot turns black, and the bark is covered with masses of pitch. A tree thus damaged will fail 



sometimes for several successive seasons to send out a new terminal shoot, with the result that 



the lateral shoots continue to grow, and the tree becomes more or less 

 distorted. 



Owners and overseers of pine groves will do well to make a practice 

 of examining the young trees each year, say in August, and when one 

 with a wilting terminal shoot is found to cut or break it off and commit 

 it to the flames. With every blighted twig thus treated from a dozen to 

 fifty or more weevils will be destroyed, and thus the numbers of the 

 insects for the coming year will be greatly lessened. All dead growth 

 or 6uc h trees as have from any cause been injured beyond recovery 

 and which might serve as centers of infestation by harboring this weevil 

 or other injurious species should be similarly treated. What is most 

 needed is a preventive, and for this purpose a good thick fish-oil soap 

 mixed with Paris green and carbolic acid, in the proportion of about a 

 pound of the former and a quart of the latter to 100 gallons of the wash, 

 is recommended. It should be sprayed in April and May on the terminal 

 shoots of the trees and repeated at the end of a month if necessary. 



MOTH CATERPILLARS AND PLANT-LICE ON TRUNKS AND LIMBS. 



The trunks and limbs of pine are also subject to the attack of sev- 

 eral insects besides those in the order Coleoptera that have been men- 

 tioned. Of these are three tortricid moths of the genus Eetinia, which 

 affect the pitch and other pines. Two other moths of similar habits to 

 the above occur on White Pine, wounding the trunk below the insertion 

 of the branches and .causing the resinous sap to exude. These are 

 the pitch-drop worm (Pinipestis gimmermanni Grote) and Harmonia, 



\(t 



FK;. 12. Pistoda ttroli : a, larval 

 mines under bark; b, pupal pint Kell. 

 cells natural size (from Riley). 



. 



The same remedies advised for other boring species, and particularly 



those specified to be used against the white-pine weevil, are indicated for the present class of 

 insects. 



Several species of plant-lice affect the White Pine. The white-pine aphis (Lachnus strobi 

 Fitch) is very abundant in the Northern States, living in colonies on the branches of trees aud 

 puncturing and extracting their juices. The so-called "pine blight," Chermes pinicorticit Fitch, is 

 sometimes very destructive, its presence being manifested by large patches of a white, flocculent 



\ 



