72 



ELEMENTARY LESSONS ON INSECTS 



some of the small Homoptera for use 

 in study ing the mouthparts. Mount 

 a number of heads on each slide, and 

 with needles separate the stylets, 

 and different views of the mouth- 

 parts will then be obtainable. 



9. Make slide mounts of fully 

 expanded wings of both horny and 

 half-horny wings. 



10. Make slide mounts of both 

 wingless and winged aphids, whole 

 specimens. 



11. Pin, mount and label for exhibition a variety of the 

 odd bugs obtained by sweeping vegetation. 



12. Home problems on crop pests (see p. 174). 



13. Routine (see p. 204). 



Fig. 26. — Diagram of a bug's 

 puncturing apparatus. U, head of 

 a leaf lopper with its beak inserted 

 into V the vein of a leaf. 



LA BORA TOR Y PROGRA M 

 A. Study of the Living Specimens. 



1. Observe in the rearing cage how the bug feeds. Find 

 the punctures made by its beak in the plant tissue. 

 Try to find one with its beak deeply immersed, sucking 

 the sap from beneath the surface. This one will explain 

 why arsenicals and other food poisons applied to the 

 surface are ineffective against true bugs. They escape 

 the poisons by feeding from beneath them. 



2. With a colony of aphids on a stem in hand, look them 

 over for : 



