202 THE CANADIAN ENTOMOLOGIST. 



Paedisca saligneana, the mis-named gall moth, is a very common insect 

 in the vicinity of Buffalo. The habits of the larva have not, I believe, 

 been published. Riley in the Second Mo. Report gives reasons for con- 

 cluding that it is an intruder on G. galhesolidaginis. It certainly is not. 



The moth begins to appear about June 20th. In a few days the minute 

 larvae may be found penetrating the stem just above the axil of a leaf 

 near the top of the plant ; sometimes they occur in a branch. The larva 

 cuts right across the stem and soon clears out everything but the bark. 

 The point attacked is soon surrounded by an enlarged ring, which is an 

 effort of the plant to strengthen its weakened stem by adding new material 

 to the outside layers ; the ring continues to increase in diameter and in 

 length upwards. The average mature gall is two and one-half times the 

 diameter of the stem in thickness, and four limes as long as broad. Dur- 

 ing the growth of the gall there is a " window," usually near the bottom, 

 consisting of a tubercle pierced with a round orifice which is temporarily 

 closed by a web membrane. The tubercle is probably at the point where 

 the larva entered the stem. The purpose of this gateway seems to be for 

 ventilation and for ejection from time to time of the castings which accu- 

 mulate at the bottom of the cavity. 



The larva during the summer is dusky, during the winter dull white ; it 

 attains a length of .56 to .6 of an inch ; head and cervical shield dark 

 brown or black ; on the segments are large piliferous spots arranged as 

 follows : on first segment one in front and below the spiracle, the second 

 has a transverse row of six, the third to twelfth each has the transverse 

 row of six and two on the dorsum behind the row. 



In the autumn, when full fed, it spins a thin lining to its house and 

 remains all winter at the lower extremity ; when spring quickens it ascends, 

 bores near the top a round passage-way, leaving, however, an external 

 scale of bark after the manner of T. solidaginis. It then spins a close 

 white cocoon reaching up to the point of final exit. It remains a pupa 

 about three weeks. When the time has come for the final change, the 

 pupa, assisted by the spines on the abdominal rings, ascends the silken- 

 lined gallery, and with the prow on its front, breaks up the door, protrudes 

 two-thirds its length, where it remains until the moth escapes, leaving the 

 pupa-skin to tell the tale. 



The pupa is rather slender, curved like a Cossus chrysalis, brown, teeth 

 on abdominal rings prominent ; there is on the front a strong beak, which 

 serves a good turn when the insect escapes. 



