May 5,1933 
Silver-Striped Webworm 
417 
Doubtless this list could be almost indefinitely extended. Judging from 
the habit of the moths in frequenting weedy waste ground in preference 
to grassy places, it is very likely that the larvae also feed on plants other 
than grasses. The foregoing plants include all on which larvae have been 
taken in the field. 
ECONOMIC HISTORY 
While it can not be regarded as a serious pest, Crambus praefeciellus 
in one or two instances has shown that it can cause considerable injury 
under certain conditions. Single larvae have been taken destroying 
wheat at La Fayette, Ind., and corn at Lakeland, Fla., Prescott, Brink- 
ley, and Hot Springs, Ark., and Knoxville and Caney Spring, Tenn. 
Larvae were received from Advance, Mo., with the report that they 
had injured 50 acres of a 300-acre cornfield. Britton's (2) recent account 
is the only published record of injury by these larvae. In this case a 
small field of com in the outskirts of New Haven, Conn., was almost 
totally ruined. The field had been in grass previously, and was plowed 
in the spring and planted to corn. The plants were attacked while 
small, and so numerous were the larvae that only a very few plants 
escaped injury and produced grain. 
Just what factors in the life economy of this species prevent it from 
more often becoming destructive can not be stated. Probably parasites, 
predacious enemies, and disease all play their parts, but nothing is known 
about these. It is apparent that this insect has not in any special way 
adapted its life cycle to extremes of climate. It has no definite protective 
resting period and consequently is overtaken by winter and unfavorable 
weather in all its different stages, some of them unfitted to resist such 
conditions. The mortality from such causes must be very great. 
If control measures were needed, probably the best would be early 
fall plowing of land intended for com the following se^on. If this 
were done, and the planting delayed as long as possible in the spring, 
the ground meanwhile being fallow and free from weeds and ^ass, there 
should be very slight possibility of the larvae surviving until the com 
germinated. If the infestation is not discovered until the com is up, 
as is usually the case, little can be done but to replant alternately with 
the old rows, allowing them to stand as long as possible before cultivat¬ 
ing them out. This method is described more fully in another paper 
(j. p-15)- 
SEASONAL HISTORY 
The earliest seasonal record for a moth of Crambus praefeciellus is 
January 30, at New Caney, Tex. It has been taken at several points 
in Florida during February. In Tennessee, where continuous observa¬ 
tions have been made for several years, the first moths make their appear¬ 
ance during April, usually toward the end of the month. It is always 
the first species of the genus to appear. On one occasion a battered 
male moth was taken at Knoxville on April 3. ^ This is more than two 
weeks earlier than the moths have been taken in other years, and the 
pupa from which it emerged may have been formed in a particularly 
sheltered location. 
After their first appearance the moths do not become abundant but 
are found singly and scatteringly throughout the greater part of the 
