GRUBS OR MAGGOTS INJURING STALK OR STEM 181 
The Wheat Straw-worm (Jsosoma grande Riley) 
In the wheat growing regions west of the Mississippi this insect 
causes much damage. Its work is of two types. Overwintering, 
mostly wingless adults lay eggs in April 
in the tender tissues of young wheat plants. 
The grubs that hatch from these feed in 
the crown of the plant, 
practically destroying it 
so that growth stops. 
After a pupal stage a 
second generation of adults 
in late May or June 
emerges. These arewinged, 
and are apt to disperse 
rather widely. The female 
lays eggs in the wheat 
stem, below the head and ° 
just above the youngest 
joint that is not covered 
Larve hatching from these 
with a sheath of leaves. f . 
t 4 
eggs feed in the stem, and ; 
remain in the straw until 
the next season. The 
Fic. Ti1.—= S E 
: 3. 112.— Work of tb 
Work of soe plant attacked will mature oe ieee net wees 
soma hordet. 9 head, but the kernels inal. 
Original. 
are apt to be small. 
Rotation is important because it will prevent damage by the first, 
Wingless generation, which causes the more serious injury. The 
overwintering larva can be killed by burning or otherwise disposing 
of the straw and stubble. 
The Wheat-stem Maggot (.Jeromyza americana Fitch) 
The evidence of the presence of the wheat-stem maggot is a char- 
acteristic blanching of the heads of wheat, rye, oats, or other small 
