4 INJURLOUS INSECTS OF 1909 AND I9Q10O. 
A WHEAT-HEAD ARMY WORM. 
(Heliophila diffusa, Walk.) An Enemy of Timothy. 
About the first of July of the present 
year the note of alarm in connection 
with this unusual visitor was first 
sounded by a telegram received from 
Detroit, Minn.—‘‘Worms damaging 
corn and grain badly here. Please send 
man to investigate.” July 5th came 
another one from MHeron Lake— 
“Green worms working on wheat, oats 
and rye. Send man to introduce 
method of extermination. Condition 
serious.’ Following these, and all in 
July, came complaints from Russell, 
Canby, Walnut Grove, St. James, Elbow 
Lake, Windom, Cottonwood, Revere, 
Marshall, Worthington, Hills, Tyler, 
Battle Lake, Ashby, Murdock, Stillwa- 
ter, Ruthton, Hendricks, and elsewhere. 
Men were of course dispatched, upon 
receipt of the above telegrams, to the 
places asking for help; and we were 
kept busy during midsummer in going 
from place to place and doing what we 
could to instruct farmers in the methods 
necessary to overcome the trouble. We 
found in every instance that the original 
sched 20 as tear ae aoe ead infestation came from old timothy fields 
Worm, A. diffusa, a, a, worms —fields that had been allowed to stand 
feeding on head of grain; b, : 
eggs under a leaf sheath; c,d, for from six or seven to ten years 
Below, fienals eats ates ewan Ome feeling the plow, and offering 
smin, ""esy °F 4T- B- ideal conditions for the increase of the 
pest. It is probable that this army worm was present and increas- 
ing in 1909, though its numbers at that time were not sufficient to 
attract the attention of the farmers. The drouth of 1910 was 
probably also in part responsible for the devastation of the current 
year. 
These army worms (see Figures 1 and 2 of colored plate) vary 
in color from green to a very dark brown, or even blackish, but 
almost invariably show characteristic stripes on sides and back. 
