150 THE CANADIAN ENTOMOLOGIST. 



Three species of Ash were found infested, Fraxinus nigra, F. 

 americana, and F. pennsylvanica. At maturity the burrow is 

 vacated and pupation occurs in the ground. The larva probably 

 falls to the ground, for such borers at maturity are clumsy and 

 cannot cling well to vertical surfaces. An indication of its early 

 presence exists in the withered leaf at point of entry, with an exuda- 

 tion of frass at the orifice; later when in the harder wood, it is less 

 easily noticed. The larva belongs to that group in the table 

 wherein the lines are broken centrally, but the species considered 

 in its entirety is very distinct. 



Stage I. — Markings indistinct, the three anterior and last 

 segments of lighter colour, middle brownish; lines not indicated, 

 tubercles show slightly, blackish; cervical and anal plates promin- 

 ent; duration of stage assumed to be five days. 



Stage II. — Generic characters in evidence, dorsal and sub- 

 dorsal lines prominent and pure white, they are broken at and 

 unindicated on the first four abdominal segments in general terms, 

 though the break is not exactly at the sutures, these middle seg- 

 ments appear as a girdle in deep purple brown; on joint ten there 

 is indication of tubercle IVa, but the chitinization is not heavy 

 and is concolorous; anal plate of much prominence, shining black, 

 cervical shield much lighter, tubercles black. 



Stages III, IV, V. — Appearance similar, the head shining 

 chestnut brown, but lacks the usual black, oblique line at the ocelli; 

 on joint ten IVa is a well emphasized plate. 



Stage VI. — The colour fades, the brown tone remaining to the 

 middle girdle, all tubercles and plates retain their prominence, 

 blackly marked, excepting the cervical shield, which is the tone 

 of the head, a yellowish brown, and edged at the side with a black 

 border. 



Maturity. — We have now a rather stout larva averaging 40 

 mm. in length and 6 mm. in breadth; the head is yellowish b'rown, 

 width 2.8 mm., the colour a whitish translucence throughout, 

 the longitudinal lines lost; the black tubercles and spiracles stand 

 out strongly, of the former special reference should point to joint 

 two, where an elongate plate occurs anterior to la and lb, the fused 

 Xa and Xb apparently; la, lb, I la show as mere dots, lib. III 



