INJURIOUS INSECTS 139 



often in great numbers. Taking' ad vantage of these pecu- 

 liarities they may be kept from corn fields by plowing deep 

 furrows in their way, which should be turned back as soon 

 as filled with bugs and new furrows made. Fences of 

 boards six inches high with the upper edge kept covered 

 with tar will keep them out, but holes in the ground should 

 be made at intervals along the line of the boards, which 

 when full of bugs should be filled in with earth, and new 

 holes made. A dusty headland or road is very difficult for 

 them to go through. If they finally reach the corn they 

 will readily succumb to kerosene emulsion. Much is being 

 done to rid the grain fields of this pest by infecting the bugs 

 with disease. This works most rapidly in moist weather, 

 but other remedies should not be put aside for this one. 



Bean and Pea Weevil (Bruchus sp.). The insects 

 known as weevils are quite common in some sections. They 



Fig. 53. The bean and pea weevil; a, peas from which weevils have 

 emerged; c, larva. 



work in the seed of beans and peas. The adult insects are 

 small beetles which lay their eggs in the flowers, where they 

 soon hatch and the young larvae eat their way into the im- 

 mature seeds. The hole by which the larva enters the seed 

 grows completely over, so that the seed appears unimpaired 



