292 MISC. PUBLICATION 273, U. S. DEPT. OF AGRICULTURE 
The different species of this genus and the hosts from the seed of 
which they have been reared are as follows: 
Species Hosts 
Megastigmus albifrons Walk____~_ Ponderosa pine. 
Megastigmus lasiocarpae Crosby_— Alpine fir. 
Megastigmus picea Rohw_____-__ Blue spruce, Engelmann spruce, and Sitka 
spruce. 
Megastigmus pinus Parfitt_______. sileer fir, lowland white fir, white fir, 
Shasta fir, and bristlecone fir. 
Megastignus tsugae Crosby_____ Mountain hemlock. 
Megastigmus spermotrophus 
Wiaciths (60!) Ss he ee eer Silver fir, bristlecone fir, grand fir, red fir, 
white fir, Douglas fir, and other conifers. 
NUT AND ACORN 
WEEVILS 
Nuts and acorns of 
various western hard- 
woods are frequently 
infested by the 
curled white grubs 
of the nut and acorn 
weevils, belonging to 
the genus Balaninus. 
The adults are me- 
dium-sized, yellow, 
brown, or nearly 
black weevils with 
robust bodies, long 
legs, and prominent, 
slender, curved or 
nearly straight beaks. 
The adults appear in 
the summer. With 
their beaks they 
enaw holes in the 
shells of new acorns 
or nuts and in these 
they place their eggs. 
The larvae feed on 
the meat and destroy 
the seed. The win- 
ter is passed in the 
larval stage, either 
within the acorn or 
in the ground. Pu- 
pation occurs the 
FicurE 9.—A and B, Adults of the ponderosa pine seed chal- pext spring, and the 
cid (Megastigmus albifrons) laying eggs through small 5 
green cones into seeds (drawings by Edmonston). En- adults emerge in the 
larged. OC, Larvae, pupae, and adults of same species of 
Megastigmus, X 3. Female above, male below. summer, Several 
