Flint, W.P.

Malloch, J.R.

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L I B R.ARYOF THEU N I VER5 ITYOF ILLINOIS570U6cno. I -24cop.6NATURAL HISTORVSURVgyDigitized by the Internet Archivein 2011 with funding fromUniversity of Illinois Urbana-Champaignhttp://www.archive.org/details/europeancornbore09flinState of IllinoisDEPARTMENT OF REGISTRATION AND EDUCATIONDIVISION OF THESTATE NATURAL HISTORY SURVEYStephen A. Forbes, ChiefENTOMOLOGICAL SERIESCIRCULAR 6THE EUROPEAN CORN BORER{A recently imported European insect injurious to corn)Bv W. P. FLINT and J. R. MALLOCHPRINTED BV AUTHORITY OF THE STATE OF ILLINOISURBANA, ILLINOIS1920P.CFIU.UB***** History Sur*»ILLINOIS PRINTING CO., DANVILLE, II L.30024-5M£loTHE EUROPEAN CORN BORERBy W. P. Flint and J. R. MallochThe European corn borer, a very destructive insect pest of corn,hops, millet, and a number of other cultivated crops in Europe, wasfound in eastern Massachusetts late in the summer of 1917. It is nowknown to be established in an area of about 1900 square miles in theeastern part of Massachusetts and southern New Hampshire, and in twosmaller areas, one in central New York centering about Schenectadyand the other in western New York in the counties bordering on LakeErie.MaleFemaleEuropean corn borer (Pyrausta nubilalis Hub.) Twice natural size.The insect in its young or larval stage bores in all parts of the cornplant except the roots, causing the most serious injury by its attack onthe tassel, stem of the ear, and ear. As many as 311 larvae have beentaken from a single hill of corn and 17 from a single ear. It has provenvery destructive to sweet corn in Massachusetts, and from our presentknowledge of its habits, it seems likely that it may become one of themost injurious corn insects in this country. Besides corn, it is knownto infest, in greater or less degree, over a hundred other plants, includingnearly all our cultivated crops.Egg-mass of European corn borer on leaf of corn; natural size.The insect was probably brought into this country in shipments ofbroom-corn, and as a number of shipments of imported broom-corn havebeen received by factories in the north central states, there is a slightpossibility that it is already established in this part of the country.There are a number of native borers which closely resemble theEuropean corn borer, the most common of which is found in smartweed.This species, however, does not cause any damage to cultivated crops,altho it frequently winters in corn stalks and the stems of a number of ourcommon weeds and grasses. Several other insects not closely relatedto the corn borer have somewhat similar habits in their manner of work-ing in the stems of plants 'and may be confused with it.Corn plants showing the characteristic breaking over of the tasselcaused by the work of the European corn borer.Ear of corn infested by European corn borer, showing the characteristicexudations of frass.Larvae of the smartweed borer (Pyrausta obumbratilis Lederer) in stems ofAmaranthus (upper) and corn (lower).The distinguishing characters of these insects are briefly as follows:The larvae or worms are greenish clay-colored and when fully grownare about an inch in length. The body has- a number of small roundblackish or brownish spots regularly arranged,each of which has upon it one or two minutehairs or bristles. Usually there is no verydistinct stripe or other markings on the back.A good idea of the general appearance of thelarva of the European corn borer and its nearestAmerican ally, referred to above, may beobtained from an examination of the figures ofthe two species in this circular. Almost inva-riably they may be separated by the size anddistance apart of the two larger spots on theback of each abdominal segment. In theEuropean species these spots are much smallerand more widely separated than in the nativespecies, their distance apart exceeding thewidth of one spot, while in the native speciesthe distance between the spots is less than thewidth of one spot. Other characters by meansof which the European species may be distin- c Larva of thecwbmartweed r-uropeanguished accurately are dealt with in a more borer | corn borerextensive paper which may be obtained upon application to the officementioned below.As several of our native borers closely resemble the Europeancorn borer, and as it is highly important that we should have an earlyknowledge of the presence of this insect if it becomes established in thecorn belt, any one finding borers attacking corn or other cultivatedplants by boring in the stems or other parts, and which resemble theabove species, is strongly urged to send the same at once to the NaturalHistory Survey, Urbana, Illinois, for positive identification.nSSH1 --Mil570IL6CCIRCULAR1-24UNIVERSITY OF ILLINOIS-URBANAC00630 12 754 175

European Corn Borer

https://www.ideals.illinois.edu/bitstream/2142/73308/2/circular09.pdf

European Corn Borer

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