1912] 



The Ottawa Naturalist. 



Ill 



of some species of Anisandrus consist merely of a short entrance- 

 tunnel and one or two short lateral brood tunnels cut immediately 

 beneath and parallel to the wood surface. Rarely, the tunnels 

 of closely allied species may branch from a common entrance- 

 tunnel. 



The number of males in some genera of this group is small ; 

 in some species of Anisandrus there are seldom more than one 

 or two males in a brood of from twelve to twenty. With some 

 species the males are apterous, and the females are fertilized 

 before leaving the brood trees. 



In two genera. Anisandrus and Xyleborus, the eggs are de- 

 posited free in the tunnels and with most species the larvae feed 

 solely upon the fungus without cutting any tunnels of their own 

 whatever. The larvae of Platypus live free in the tunnels until 

 nearly ready to pupate, when short pupal cells (cradles) are cut 

 from the sides of the tunnels deep within the wood. 



The Shot-hole Borer. Anisandrus dispar. Adults, an antenna, and 

 tunnels in an apple branch. (After Hubbard). 



In Corthylus, Trypodendron, Pterocyelon and Gnathotrichus 

 the eggs are laid in shallow niches cut by the female along the 

 sides of the tunnel, and usually well within the wood; the 

 larva? extend these niches away from the tunnel, forming larval 

 cradles, in which they remain until mature. The length of the 

 completed cradles is slightly great er than that of the adult beetle. 



