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Show METHOD OF CONTROLLING COVTROLLING COVTROLLINGCORN CONTROLLINGCORN CONTROLLINGCORN CORN EAR EAI WORM womu E EXPLAINED EXPLAINEDBy PLAINED By J C Hogenson HogensonUSA HogensonU USA U S A C Extension AgronomIstThe AgronomistThe Agronomist AgronomistThe The control of the conn com corn ear worm is isn isa isa n a rather difficult problem because It Itcannot itcannot itcannot cannot be handled by spraymg1"lth spraying spraymg \1"lth 1"lth 1lth with 1"lthany withany ' \ ; withany " any kind kmd of chemical poisonWhen poisonWhen poison poisonWhen When its life cycle is understood understoodhowe\ei understoodhowe ei , howe\el howe el however \ , , its control becomes a : . rather rathersimple rathersimple rathersimple simple , though continuous contmuous , processThe processThe process processThe The adult of the corn ear worm is as a amoth amoth amoth moth " which "Wch Wch lays its eggs at random on onany onany onany any part of the corn com plant One fe- fe female female fe female - - male moth lays about 1000 eggs dur- dur during during dur during - - ing a aJ : period of about 12 daysThere daysThere days daysThere There al aie are e usually from one to four fourgeneratIOns fourgenerations fourgenerations generatIOns m in a year , depending upon uponthe uponthe uponthe the length of the \ worm orm seasonThe seasonThe season seasonThe The eggs hatch in about eight days daysafter daysafter daysafter after they are deposited After hatch hatch- hatching hatching hatching - ing the worm enters the ear and andgrows andgrows grows rapidly It is during durmg this stage stageof stageof stageof of Its development that damage to the thecorn thecorn thecorn corn Is doneWhen doneWhen done doneWhen When fully grown the worm lea\ lea leaes leases leasesthe leavesthe \ < es esthe the ear , usually by boring out through throughthe throughthe throughthe the husks , and drops to the ground ground.It groundIt . . It enters the soil soll and bores down to a . adepth adepth depth of from one ne to tD nine rune inches inches.Here inchesHere . . Here pupation takes place Dunng During DunngtWs Duringthis Duringthis tWs this period it is very delicate and andhelpless andhelpless andhelpless helpless When the changes have havebeen havebeen havebeen been completed , which usually take takeabout takeabout takeabout about 14 days , the full-giown full giown full.glOwn fullglOwn full-grown grown - . moth mothemerges moth.emerges mothemerges . . emerges from the sollThe soilThe soil soll soilThe The control of this pest lies mostly mostlyin in indestroying destroying -destroying - the pupae in the soli soil soliduring soilduring soliduring during its delicate and helpless period . This co consists ists of three practices practices(1) practices1 (1) 1 ( ( ) Rotation Do not plant corn on onthe onthe onthe the sam same ground two years in succes succes- succession succession succession - sion (2) 2 ( ) Deep weekly weeUy cultivations cultivations(3) cultivations3 (3) 3 ( ) Deep fan fall plowing to destroy destroj the theeggs theeggs theeggs eggs of the last generation If U these thesethree thesethree thesethree three practices are used uscd the corn com ear earwonn earworm earworm wonn worm can usually usuaJIy be kept tmder tinder tmdercontrol tindercontrol undercontrol control |