96 INSECTA 



(1) What organs in man are the ''balancers" or the 



organs of the sense of equihbrium? 



(2) Sketch the alulets and the ''balancers" as you see 



them. 



(2) The Legs. 



(a) Are they alike? 



(b) Are they fitted for running or for jumping? 



(c) Are there any hooks or pads on the feet? If so, of 



what use are the pads? 



(d) How does the fly walk on the ceiling? Can the 



grasshopper, beetle, or crayfish walk on the ceil- 

 ing? 

 5. Abdomen. 

 (1) Shape? 

 . (2) Size? 



(3) Number of segments? 



(4) Ovipositor or sting present? 



HEMIPTERA 



The Squash Bug, or the Cicada 



The bugs, cicadas, squash bugs, plant lice, etc., have a sucking 

 beak. The mandibles and maxillae appear as slender, bristle- 

 like organs, for which the lower lip forms a sheath. 



1. The Sucking Beak. Look on the ventral side for the 

 beak. Examine it with a glass and make out the following 

 parts : 



(1) Sheath formed of lower lip. 



(2) Mandibles and maxillae, four slender bristle-like organs 



within the sheath. 



2. Wings. Do you find half of the anterior wings hardened, 

 as the name (hemi, half, pteron, wing) indicates? 



3. Insecticide. The aphides, or plant lice, and the scale 

 insects belong to this order. Would you exterminate them 

 by poison insecticide, contact insecticide, or by a "smudge"? 



Prepare several spraying solutions (see pages 66 and 68) 

 and experiment with them upon plants infested with plant 

 lice or squash bugs. Be careful not to have the solutions too 

 strong. Record and explain results. 



