THE WAR ON INSECTS 297 



and will eat it by choice even when a corn plant grows 

 near by. We take advantage of this habit by making 

 up a mixture of 'white arsenic one pound, to wheat 

 bran seventy-five pounds; mingle thoroughly, moisten 

 ■with sugar water enough to make a soft mush and put a 

 spoonful in the hill of plants to be protected. There 

 will be dead cut-worms next morning, and no further 

 cutting of plants. Sometimes, where a field of grass 

 has been plowed down and cut-worms are known to be 

 present, rows of the dry bran and arsenate mixture are 

 drilled at ten-foot intervals across the field to attract 

 and destroy the worms before the crop is set out or is 

 up, as the case may be. Paris green may be used in- 

 stead of arsenic, but the latter is cheaper. Chickens or 

 other farm animals liable to eat this poisoned bran 

 should of course be kept out of fields so treated. 



Grasshoppers of certain injurious species have an 

 abnormal fondness for moist horse manure and great 

 numbers can be killed off by mixing one pound of 

 arsenic with three gallons of droppings and spreading 

 where the insects are most numerous. It is better to 

 use small quantities several days in succession than 

 large quantities at one time, because as the material 

 dries out it loses its attraction. 



To keep borers out of fruit and shade trees, all sorts 

 of mechanical protections have been devised. The use 

 of lime-wash has been already referred to, and that is 

 most wide-spread. Sometimes soap, carbolic acid and 

 arsenic are added, and help a little toward its effective- 

 ness, because the poison may kill the parent beetles 

 when cutting a place for the egg, or the young larvae 

 when attempting to enter. Sometimes the entire trunk 

 is cased in wire mosquito netting held at a distance of 

 at least half an inch from the bark at all points, and 

 sometimes only the lower portion of the trunk is so 



