THE CONTROL OF INJURIOUS INSECTS 397 



above the ground, the frames holding the screens should be placed in 

 position soon after the plants are set out or the seeds planted. They 

 can be readily removed for a short time whenever weeding, cultivation 

 and watering are necessary. 



(c) Wire-netting. — Wire-netting is often placed about trees to 

 protect them from the Peach-borer, and the Round-headed apple tree 

 Borer. 



Fig. 251. — Tool and device for cutting disks. (AJtci- Britlon.) 



{d) Single-ply Tar Felt Paper Disks. — Used to protect cabbage and 

 cauUfiower plants against the cabbage-root maggot (Figs. 251-253). 



6. The Use of Traps, Trap Crops, Etc. 



The following forms of traps are sometimes used to advantage: 

 (a) boards or chips; (b) special crops; (r) poison baits. 



(a) Boards or Chips. — Squash bugs, cutworms and other insects 

 may be readily trapped in large numbers by placing small bits of 

 board or chips or bunches of grass among the rows of plants where 

 these insects hide. 



