228 DRY AND MESOPHYTIC FOREST COMMUNITIES 
c) Shrub stratum.—Here we have the young pines, the juniper, and 
the willows. From the evergreens we secured several spiders (Philo- 
dromus alaskensis, Dendryphantes octavus, Theridium spirale, and 
Xysticus formosus) (172), and with them sometimes an assassin-bug 
(Diplodius luridus). On the willows are some characteristic willow- 
feeders, but they appear to prefer the more mesophytic depression 
shrubs. 
INHABITANTS OF THE PINE 
Fic. 195.—The nest of the kingbird (Tyrannus tyrannus Linn) in a pine tree. 
The nest is made from the string of a fisherman’s net. 
Fic. 196.—The pitch mass of the pitch-moth (Evetria comstockiana?); twice 
natural size. 
Fic. 197.—The larva removed from the mass. 
Fic. 198.—The larva of the pine engraver beetle (Ips grandicollis); much 
enlarged. 
Fic. t99.—The adult of the same, from Pinus banksiana. 
d) Tree stratum.—The pine is attacked by many borers and few 
leaf-feeders. Of the borers several broad-headed grubs have been taken. 
The bark beetle (Ips [Tomicus] grandicollis) (Figs. 198, 199) (137) is 
common under the bark of dead and dying trees, especially on the north 
side, where the trees stand unprotected. The twigs are attacked by the 
