SHADE TREE INSECTS 



75 



The egg is colorless, 1/25 inch long and 1/5 as thick, curved, and with blunt, 

 rounded ends. 



The mature larva is about 1/3 inch long and 1/16 inch thick. It is light yellow 

 with a dark yellow or light brown head. 



1 """' 



\ 



Maple Petiole Borer 



1. Larva in petiole or leaf stem. Enlarged. 

 3. Exit hole of larva in leaf stem. Enlarged. 



Adult female. Enlarged. 

 Leaves with severed stems. 



Courtesy, Conn. Agr. Expt. Station. 



L^fe History. The egg is laid on the leaf stem at the baseof the blade, in early 

 May. The young larva tunnels in the leaf stem and feeds on the inner tissues, 

 leaving only an outer shell filled with frass and excrement. The outer sheath 

 is usually eaten almost through by the time the larva matures, which is about 3 

 weeks later, and the stem breaks at that point. Mostof the leaf stem remains on the 

 tree a week to 10 days and then drops off. The larva contained therein emerges 

 through a small hole in the side and goes into the ground 3 or more inches where 

 It pupates in an earthen cell in which it spends the winter. The adult emerges 

 the following May. 



