/if 
 
 CORN EARWORM 
 
 a, Moth (or adult), and eggs on silks; b, eggs; c, earworm feeding in 
 ear of corn; d, pupa in a cell; e, color phases ot the earworm. (All 
 except b about IV-, times natural size; b 5'j times natural size.) 
 
 (See other side for life history and control) 
 
 Bureau of Entomology anJ Plant Quarantine 
 United States Department of Agriculture 
 
 Picture Sheet No. 11 
 
UNIVERSITY OF FLORIDA 
 
 C OKX EAKWOKM 3 1262 08721 6700 
 
 {flelinthis anjiigtrn (Ilhn.'i) 
 
 Life Ilislorv 
 
 Allhouirh tho corn carwoiin ;it lacks many cultivatod crops, it is 
 dealt with here only as an enemy of corn. The e^r^s arc laid by a 
 motli. or miller, usually on the corn silks. The eo:<j^s hatch in from 2 to 
 S days, and the tiny larvae, caterpillars, or "worms," feed dowmward, 
 following the silks into the ear tip. Scmmous damage to the ear fre- 
 quently results from their feeding and from the fermentation or molds 
 which follow. When full-grown, the larva leaves the ear, enters th*' 
 soil, and becomes a pupa, and from this the moth emerges. About .30 
 days are required in midsummer for complete development from ogg to 
 adult. Pupae produced late in the summer or in the fall may pass the 
 winter in the soil and become moths the following spring or early in 
 the summer. Usually two complete generations are developed annu- 
 ally in the North, but in the South there may ])e as many as five or 
 more generations. 
 
 Control 
 
 Injury to field corn can be reduced by growing \ari(^ti(»s having long, 
 tight husks, and, in the South, by planting early. 
 
 To protect early-market or home-garden sweet corn, injcu't into thc^ 
 tip of each ear about ^i teaspoonful (^4 to 1 cubic centimeter) of refined 
 white mineral oil (viscosity 100 to 200 Saybolt) containing 0.2 percent 
 of p}Tethi*ins. If ready-mixed material is not obtainable, use 1% fluid 
 ounces of oleoresin of pyrethrum (containing 20 percent of p\Tetlmns) 
 to 1 gallon of the white oil. The injecting should be done after the 
 silks have wilted and before they have begun to turn brown. If it is 
 done before the silks have wilted, poorly fdled ears may result. Al- 
 though the mixture can be applied with a pump-type, long-spouted oil 
 can, it can be best applied by using a special oiler. A description (with 
 illustrations) of the special oiler will be sent, without charg{\ on applica- 
 tion to the Bureau of Entomology and Plant Quarantine, United States 
 Department of Agriculture, Washington, D. C. 
 
 April 1941 r. S. (JoviTiuncnt rrintin^ Oflice 
 
 For sale by the Superintendent of Documents, Washington, D. C. — Price 5 cents