THE PITCH-PINE LEAF GALL-FLY. 799 



* In the year 1862 or '63 I observed in an isolated young pitch-pine 

 {Pi7ms rigida) at Brunswick, Me., that many of the leaves or needles 

 were less than half as long as usual, and much swollen at their base, as 

 seen in the adjoining cut. These deformed needles were quite numer- 

 ous on the tree, and, so far as I am aware, have not been previously 

 noticed. 



The larva is situated at the base between the 

 inner two of the three needles, which grow from 

 one-third to one-half of their normal length, and 

 by the irritation set up by the worm the united 

 base of the leaves swells into a bulbous expan- 

 sion about the size of a pea, or four times the 

 original thickness of the needle, while the third p-,o 271— pitchpine needles 

 or outer needle is sometimes not altered in size, shortened and deformed by 

 but simply shortened and aborted. The bud- fly'!_!From pTct^rd. ^ "* 

 scales of the primary leaves are burst and hang 



down in shreds about the bulbous swelling of the secondary leaves or 

 needles. The larva, which was found in the autumn of the same year 

 (September 22), does not apparently bore into leaves, as it has no means 

 of making its exit unless it works its way out of its prison through an 

 oval hole between two of the leaves. It has to do so in some way, how- 

 ever, for when fully fed it makes its exit, ascends to the terminal buds, 

 and pupates on one of them, exposed to the air. Sometimes there are 

 two larvae, one on each side of a leaf. 



The cocoons are pale, oval, and covered with the pitch which exudes 

 from the buds of the tree, and were found May 20. When the fly issues 

 from the cocoon it creeps half way out of its cocoon, leaving its pupa- 

 skin partially remaining, with the old pupal integument of the antennte, 

 wings, and legs separate. 



On the 10th of June I opened the cocoon and found the pupte of a 

 chalcid fly, and afterwards found specimens of the adult, which, on 

 making their exit, bore small holes through the sides of the cocoon. 



The history of the species is apparently somewhat as follows : The 

 eggs are probably laid at the base of the needle early in May, or pos- 

 sibly in the preceding autumn, or possibly the larva winters in its gall, 

 though this is not probable. At any rate the worms pupate within spun 

 silken cocoons about the middle or the third week in May, and the 

 fly probably appears in the early part or about the middle of June, 

 when the eggs are laid for the second brood of worms, which we have 

 found September 22. A large percentage are destroyed by the chalcid 



fly. 



These deformed needles were observed on the pines of the campus of 

 Bowdoin College, Brunswick, Maine, August 4, 1882, though no larvae 



* The following account and figure are taken from Hayden'a Tenth Annual Report 

 of the U. S. Geographical and Geological Survey of the Territories for 1876. Wash- 

 ington, 1878, p. 527. 



