National Geographic : 1941 Aug
236 TeNational GeoE ugly little larvae that weaened thetassels till they drooped athalf-m st,that atethe heart out of the stalks, tacded thekernels, and bored lengthwise throug theear. Badly infested fields looked asifatroop ofcavalry had charged acrossthem. The culprit wassoon ident fledastheEuro pean corn borer, the world's worst menace to Indian corn (ColorPlate III.Strong though circumstantial evidence points toitsarrival in broomcorn from Hungary orItaly before the "coast defense" quarantine inspections and fumigations were authorized bylaw. Great Lakes Water Haard Crossed As the summerdays pass took wings, for theborers a: stage of a strong-flying moth. the wind they drifted deeper i of promise, the females findii on which to "shingle" their Even the Great Lakes failed 1 flyers alighted on the water, flew on again. Now, in 1941, the advance corn borer harry the tasseled sin and Illinois. This lowly insectwhich oni the wild hops of Central Eu billions strong, wellwithin th of the greatest corn-growing the middle-western Corn I north it extends toNorth C into Canada. Besides corn, plants, the dahliasinflower f the notorious drugplant ma But the pest is not having way. With the wise counsel Entomology, farmers arek clean-cutting stubble shor shredding stalks, or plowing Borers winter in stalks v cannot reach them,but theli pecker plucks them outlik Christmas pie. Parasite hunters,prowling have brought backseveral of enemies (page 246). One, brown parasitic fly from Orient, is now more abundar Massachusetts thananywhere Corn borers are subject to but their life inside thecor: hard to use this weapon asthd,the"worms" ,ebutthelarval With theaidofntothis vast land igplenty ofcorn flatlittle eggs. ostop them; therested, and then inghosts ofthefields ofWiscon :efedhumbly on•ope now stands, eeastern borders region onearth, elt.South and irolina and deep ittackles potato ardens, and even rijuana. things allitsown oftheBureau ofeping cornfields t,destroying orthem well under. here most birds :tledowny wood eplums from aEurope and Asia, theborer's worst Delicate, light urope and thetinsoutheastern else onearth. fungous disease, plant makes it"milky disease" is being used against Japan sebeetle grubs. Japanese Beetles, Gems ofIllOmen Over an ever-widening 4 which now includesthe Nati( deners and golfers,farmers a.astern territory in'sCapital, garndfruit growers graphic Magazine aregetting aforceful introduction totheJapa nese beetle. Often itappears inhuge numbers, asmany as296 ononeapple, like anincrusta tion ofevil little gems (Color Plate IV). Unless protected bypoison sprays, awhole crop offruit may beeaten ordamaged. Corn, vegetables, and shade trees areattacked. Rose bushes and other plants fade asleaves and petals areconsumed. Inspring thelarvae, eating grass roots, turn lawns and golf greens brown. "How didthey gethere and what's being done about 'em?" wonders theaverage suburbanite, laying about him with hisspray gun. Togetthebest answer Iwent toMoores town, New Jersey, where theFederal Japanese Beetle Laboratory carries ononeofthefiercest wars ever waged against aninsect. Five miles away, near Riverton, New Jersey, theJapanese beetle was discovered in1916 byH.B.Weiss and E.L.Dickerson oftheState Department ofAgriculture. Itprobably arrived inthelarval stage, insoilaround theroots ofaJapanese irisorazalea. Weiss and Dickerson found several beetles onahaw thorn bush and bycareful searching collected adozen. Today inabadly infested orchard oneman could shake offaton. Many parasites have been imported, and five ofthese little policemen arenow onregular duty here. Best areTiphia vernalis and Tiphia popilliavora, small digger wasps which laytheir deadly eggs onthelarvae inthesoil. These wasps arenow abundant inmany places. Each year theentomologists bait them with honey, catch thefemales, and establish new colonies where needed. Athird parasite, Centeter cinerea, isatachi nidflywhich deposits itseggupon theadult beetle with adive soquick theeyecannot follow (Plate IVand page 227). Billions ofbeetles arecaught intraps (page 226) and turf isgrub-proofed with poison. Against such weapons thebeetles pittheir vast reproductive powers and their wings. Good flyers, they arespreading north, south, and west atfive ortenmiles ayear. Broad Delaware Bay proved nobarrier, forone beetle outoffive that fellinto thewater was still alive when washed upontheother side. Fighting anInsect with Bacteria But meanwhile theGovernment scientists had discovered avital fact. Inrare instances thegrubs intheground were attacked bydiseases. One especially seemed promising. Microscopic spores, multiplying bythebillions intheir bodies, turned their blood, orlymph, from awatery toathick milky fluid and caused death inabout 12days.