UNITED STATES DEPARTMENT OF AGRICULTURE 
FARMERS’ 
BULLETIN 
Wasuincton, D. C. Poe JUNE 9, 1916 
Contribution from the Bureau of Entomology, L. O. Howard, Chief. 
THE CORN AND COTTON WIREWORM 1! IN ITS RELATION 
TO CEREAL AND FORAGE CROPS, WITH CONTROL 
MEASURES. 
By Epmunp H. GIBSON, 
Scientific Assistant, Cereal and Forage Insect Investigations. 
INTRODUCTION. 
During the three years which have elapsed since the investigation 
of the corn and cotton wireworm (fig. 1, 6) was begun there have 
been constant requests by farmers and others for remedial measures, 
and it is in answer to and underground stems 
these requests that the : of plants which are 
present paper has been thereby weakened and 
prepared. The injury, stunted or killed. 
as in the case with other 
“wireworms, is caused by 
the feeding of the worm- 
like young or larve of 
slender beetles, known 
as “click beetles” or 
“snapping beetles,” 
upon the roots, sprouts, 
EXTENT OF DAMAGE 
BY THE CORN AND 
COTTON WIREWORM. 
These wireworms 
have been known totally 
to destroy corn through- 
out fields of large acre- 
Fic. 1.—The corn and cotton wireworm: a, Adult, or beetle; b, larva, or wireworm. Much 
enlarged. (Hyslop.) 
age. However, this is not usually the case and the attack is most 
frequently concentrated in “spots” scattered throughout the field, 
the plants in these spots being wholly destroyed. In other parts of 
the field there may be slight injury as shown by the dwarfed ap- 
1 Horistonotus uhleri Horn; order Coleoptera, family Elateridae. 
Norr.—The object of this bulletin is to set forth in a popular form what is known of 
the habits of the destructive corn and cotton wireworm, in order that farmers and 
planters may more effectively carry out control measures and be able better to handle 
infested areas, that the injury may be reduced to a minimum. 
' 88491°—Bull. 733—16 
