100 



miles from Colonial Beach, considerable damage liad been done to young 

 corn planted about the 1st of May in a very large field which was grown 

 to corn the previous year. The damage was first noticed by Mr. Xew- 

 ton about July 1, although the worms had undoubtedly been at work 

 for several weeks at that time. At the time of my visit (August 9, 1891) 

 at least 98 per cent of the worms had transformed to pupte and the moths 

 had issued, I found some pupoe, however, and a few larvte which had not 

 yet changed. This corn by July 1, when the damage was first noticed, 

 had reached a height of from a foot to 18 inches, and every infested stalk 

 on August 9 remained at tliis height, stunted and deformed, the only 

 visible sections of the stalk averaging not more than 1^ inches in length. 

 The larval burrow was invariably in the first section and usually ex- 

 tended down into the tap root, and in no case were more than two bur- 

 rows found in the same stalk. 



From these observations we may conclude that the insect is normally 

 two-brooded in Virginia, the moths laying the eggs for the first brood 

 during May, the larvai arriving at maturity from the middle of July 

 on, transforming to pupte and issuing as moths in from ten days to two 

 weeks later. The eggs for the second brood must be laid soon after- 

 wards on the well-grown stalks and the larvte must be full-grown by 

 harvest time. Judging from our experience with the specimens from 

 South Carolina in 1881 and with the individuals in sugar-cane in the 

 spring of the same year the insect will hibernate in the larval state in 

 the stalk and in this fact we have our simple means of cure. 



With the more careful and thorough methods of cultivation in the 

 Xorth this insect will have no chance for its life. It will reach its maxi- 

 mum in localities like parts of South Carolina where corn is simply 

 stripped for fodder iu early August and the bare stalk with tlie ear 

 attached stands until afterthe cotton is picked, ginned, and shipped, and 

 where even after the ears are harvested the stalks are seldom burned. 

 In Virginia, however, the conditions are nearly as favorable for the con- 

 tinuous develoijment of the insect. Where it is not intended to follow 

 corn with winter grain the corn is cut in October and the butts stand in 

 the ground until the following spring, affording the larvfe safe places of 

 hibernation. Even in plowing for another crop of corn in the spring 

 many of the old stalks are not destroyed but still remain standing 

 through Aviuter. Under these conditions there is no check whatsoever 

 to the increase of the pest. Where winter grain follows corn the stalks 

 are not thoroughly dragged off (they seem never to be systematically 

 pulled as in some parts of Maryland and other localities) and even 

 when dragged off and collected they are not burned. 



Where, however, the old stalks are systematically removed from the 

 field and burned after harvest or during winter, or where a constant 

 rotation of crops is practiced, the corn stalk-borer will never become a 

 serious pest, and the Virginia and South Carolina farmers have it in 

 their hands to check it at any time by pursuing these methods. 



