THE PINE LEAF-MINER. 795 



slender than those of the pitch pine, and, from observations made upon 

 it, it would seem that one leat^ if small, does not afford all of the food 

 needed by a larva. 



"When found on the 1st of January this specimen was hibernating, 

 the mouth of its burrow being covered with a thin silken curtain. Six 

 days after, being transferred to a warm room, it was found that this 

 curtain had beeu broken and the insect had left its mine. It was soon 

 found on another leaf, and the same day formed a new burrow, where 

 it continued to eat until January 23, at which time it had completely 

 excavated the leaf. After this date all operations appear to have been 

 suspended, and there were no signs of life in the burrow until March 3, 

 when a Proctotrupid parasite issued. 



" Leaves of P. rigida are frequently observed to be completely mined 

 out, and nearly full-grown larvae are occasionally found crawling about 

 ovet the leaves and twigs ; so it seems probable that with this species 

 of pine also two leaves may sometimes be successively mined by the 

 same larva. 



"The full-grown larva is nearly 5'"'» in length (.19 inch). Its color is 

 light brown, with the head and prothoracic shield and the anal plate 

 black. The body is clothed with a few delicate hairs. The form of the 

 larva is shown in the figure. Upon reaching full growth the larva spins 

 a slight covering to the mouth of the mine and retreats a short distance 

 above it (from lO'"'" to 15™™). There, after spinning a few supporting 

 lines of silk, it transforms to a long and slender chrysalis, light-brown 

 at first but afterwards nearly black. When removed from the mine the 

 pupa is very active, jerking the short end of the abdomen (which ex- 

 tends below the wing cases) from side to side with rapidity. The dura- 

 tion of the pupa state is from ten to fourteen days. The moth makes 

 its exit from the pupa shell without disturbing the j^osition of the latter, 

 leaving it attached by its threads some distance up the mine, and works 

 its own way to the entrance. 



"There are certainly two broods of this insect each year, probably 

 three, and possibly more in exceptional seasons. Of the general hiber- 

 nating habits of the genus, Stainton says: ' Of a few species the young 

 larvae live through the winter, but I believe the greater number pass 

 the winter in the egg and pupa state.' With the present species the 

 nearly full grown larvae have been found during the winter, but not in 

 great numbers. What we consider to be the egg of this species has 

 also been found in apparently healthy condition in midwinter, and 

 the insect, without much doubt, hibernates in both of these forms, and 

 possibly in either of the others. The moths of the first brood issue 

 during the entire month of June, the difference between the earlier 

 and later ones probably depending upon the form in which they hiber- 

 nate. 



"As we have stated before, larvte almost identical in appearance 

 with those found on Pinus rigida in New York have been discovered on 



