58 



brooded. From the fact that the exuding pitch offers so much protection to the insect,, 

 it is scarcely likely that any remedy would r^ach it. The knife seems to be the only 

 resource. A small four- winged parasite attacks the borer in the larval state, the chrysalis 

 being often found filled with the cocoons of this useful friend. 



Comstock's Retinia — Retinia Comstockiana, Fernald. 



This insect as yet has only been ob- 

 served on the pitch pine {Pinus riffida), but 

 as it is probable that it will sooner or 

 later be found to attack the white pine it 

 will be briefly noticed. 



The perfect insect is a small moth of a 

 light grey colour, varied with darker shades 

 of rusty brown, which measures, when its 

 wings are spread, nearly three-quarters of 

 an inch across. The eggs are laid on the 

 terminal shoots of the trees, and the larvae 

 are found in the early part of the summer 

 boring into the twigs and small branches, 

 causing an exudation of resin, and sometimes 

 girdling them. The larvae, when full-grown, 

 are nearly half an inch long, of a yellowish 

 colour, with a brown head, a patch of the 

 same colour on the next segment, and a few 

 polished brown dots on each ring, and from 

 every one of these there arises a single hair. 

 The larva changes to a chrysalis within the 

 Vjurrow from which eventually the moth 

 escapes. In fig. 28 we have the insect 

 represented in its several stages, also a small 

 branch of an affected tree and a section of 

 one of the bored twigs. 



The Pine Leaf-miner — Gelechia pinifoliella 

 (Comstock). 



This insect was first described by Prof. 

 Comstock in his report to the Department 

 of Agriculture, Washington, for the year 

 1879. It has been found mining the leaves 

 of different species of pine in many parts of 

 the United States, and although as yet unrecorded in Canada, will very probably be- 

 found here. The larva is very minute, in the figure it is much magnified ; the line below 

 indicates the natural size. It lives within the leaf on the soft tissues, and its presence 

 is soon indicated by the change in colour which takes place in the part affected ; it 

 becomes brown, and on examining the leaf, or that portion of it which is discoloured,, 

 it is found to be entirely eaten out, and to contain, if in season, the insect, either in 

 the larval or pupal condition. In fig. 29 the work of this tiny insect on the leaves is, 

 shown. The moth, chrysalis, and larvae ai-e all represented, but much magnified. 



The larva, when full-grown, is about one-fifth of an inch long, of a pale brown, 

 colour, with a black head and a black patch on the upper part of the next segment. It is. 

 also sparingly covered with short, fine hairs. The change to a chrysalis takes place: 

 within the mined leaf, and in summer the moth escapes in about a fortnight. 



The perfect insect, when its wings are spread, measures about three-eighths of an 

 inch across ; it is of a brownish-yellow colour, dotted with fuscous scales. The fore- wings 

 are crossed by three white lines, as shown in the figure ; the hind-wings are pale grey,, 



Fig. 28. 



