136 The Ottawa Naturalist. [Jan. 



Air. Harrington showed twigs of oak from Meach Lake, 

 Que., from which he had reared the eerambveid, Elaphidion 

 parallelum. The larva tunnels the twigs for several inches and 

 pupates therein, finally emerging through the base of a broken 

 twig. This beetle is a close relative of the well known Oak Twig 

 Pruner, Elaphidion villosum, which was quite injurious to oaks 

 on the St. Lawrence Island Parks in 1912 and 1913. The well 

 known habit of these larvae in girdling the twigs, causing them 

 to drop and owing to which injury they are broken during wind 

 storms, was discussed. 



Mr. Swaine exhibited specimens and work of Ambrosia- 

 beetles collected by him the past summer in British Columbia, 

 and briefly discussed the habits of the genus Gnathotrichus , and 

 of a new species of the genus Platypus from the West Coast. 

 Tunnels of G . sulcatus I ec. were shown from Western Hemlock. 

 Their black tunnels, about the size of a pencil lead, penetrate 

 the wood for about six inches, and give off lateral branches 

 parallel with the wood surface. Along the sides of the tunnels 

 egg-niches are cut, in which eggs are laid. The grubs enlarge 

 the niches to a length slightly greater than their own when 

 mature, and pupate therein with the head towards the tunnel. 

 These short larval tunnels are known as larval or pupal cradles. 

 After transformation the young adults enter the egg-tunnel, 

 and after remaining a longer or shorter time in the tunnels or in 

 the cradles, they emerge in early summer through the entrance 

 tunnel cut 1 v the parent 1 eetles to attack fresh logs and stumps 

 or dying trees. The chief food of the larvae, and an important 

 food of the adults, is a species of fungus which grows in a dense 

 glistening laver on the tunnel walls. Mr. Swaine has recently 

 worked out the life-history of several of these interesting and 

 little known fungi. The fungus is carried by the beetles to new 

 tunnels and rapidly spreads over the fresh wood of the tunnel 

 sides and upon the walls of the larval cradles. The fungus 

 stains the walls of the tunnels black for several millimetres. 

 The habits of the species of Platypus are somewhat similar to 

 the above, but the eggs are deposited free in the tunnels. 



Mr. Criddle spoke upon certain phases of his investigations 

 into the habits and life-histories of the various species of June 

 Beetles (Lachv.ostcrua) which he had been studying as a field 

 officer of the Division of Entomology. He related how the 

 different species were often quite local in distril ution owing to 

 each having preferences in matters of soil and moisture as breed- 

 ing places. Thus, L. dubia was taken in all its stages within an 

 area of a few feet and the duration of its life cycle probably 

 discovered in a single day. He also spoke upon the hibernating 

 habits of the larvae, instancing how some species remained 



