160 HXPERIMENT STATION RHCOBD. 



of the young growing corn plant is disastrous to the root system; the roots, 

 first dying at the tips, soon become of little use to the plant, allowing it to 

 die or to become more or less dwarfed. Eggs are often deposited in plants of 

 even less than one-half inch in diameter. The larvae on hutching burrow into 

 the heart of the plant and cut off the growing bud, thus killing the top ; they 

 then direct the burrowing downward only to devour the stub, leaving them- 

 selves without food and thus perish. " Plants of more than one-half inch 

 diameter which become infested with larvae make very poor growth, being very 

 slender, rarely reaching a height of more than 2 or 3 ft. before tassel ing, and 

 do not produce shoots or ears. Those that do not become infested until they 

 are half grown may produce small ears." Sometimes there are 3 or 4 larv;e 

 in the same plant, their burrows often running into each other. In badly 

 infested fields 2 larvae occur quite often in the same plant, although 1 is the 

 usual number and is sufiicient to ruin the plant. 



" The length of the larval life ranges from 40 to 50 days, as indicated by 

 laboratory observations and checked by collections in the field. They begin 

 maturing and pupating by August 1, pupation reaching the maximum by 

 August 20, and with the exception of a few stragglers all are mature and 

 changed to pupae by September 1. The larvae, on fini^ing their growth, descend 

 to the lower part? of the burrow, to the crown of the taproot, cutting the pith 

 of the cornstalk into fine shreds with which they construct a cell where they 

 inclose themselves for pupation. . . . The pupae occur mostly during the 

 latter part of August and first part of September and are always to be found 

 in their cells in the larval burrows near the crown of the taproot and nearly 

 always below the surface. The pupal period is from 10 to 12 days. . . . The 

 adults begin to issue about the middle of August and continue to do so until 

 the middle of September. Some of them leave the pupal cell, but most of them 

 remain there for hibernation." The adults which hibernate in the pupal cells 

 issue in late spring about the time young corn is sprouting. They kill the 

 small plants outright and injure the larger ones beyond recovery. Females issu- 

 ing from hibernation commence to oviposit after a few days feeding on young 

 corn. There is only one generation a year. 



The pulling up and burning of the stubble is thought to be the most practical 

 means of dealing with the pest and at the same time destroys the lesser corn- 

 stalk borer {Diatrcea saccharalifi) . Care must be taken in pulling up infested 

 stalks that they do not break off above the beetle, leaving the pest in the 

 ground. As the infested stalks have a very poor root system, they are easily 

 pulled. Spraying young cornstalks with arsenical fluids at the time the beetles 

 are making their attacks is stated to be very laborious and not very effective. 



The alfalfa weevil (Phytonomus murinus), F. M. Webster (U. 8. Dept. 

 Agr., Bur. Ent. Circ. 137, pp. 9, figs. 10). — This circular, presenting a brief de- 

 scriptive account of the alfalfa weevil and the injury it causes, has been pre- 

 pared chiefly for the purpose of reaching alfalfa growers and obtaining in- 

 formation as to the appearance of the pest in new localities. 



It is thought that in dealing with this pest the work of the Bureau of Ento- 

 mology should be, first, to endeavor to restrict the pest as effectually and as 

 long as possible to its present area of infestation, and, second, to use every 

 means in its power to control it, in the meantime, within this area. Quarantine 

 between the different States is considered wholly useless on account of the 

 agency of the railroads and winds as factors in the dispersion of the beetles. 

 " The most inexpensive and practical means of controlling introductions of the 

 pest by railroads appears to be in the close surveillance of the railroad right 

 of way and the stamping out of incipient outbreaks as soon as discovered." 



