INTRODUCTORY STUDIES OF LIVING ANIMALS 17 



What do you discover about these bugs to indicate that 

 they are really insects ? 



3. What can be said about the number of scale bugs ? 

 Why are they difficult to exterminate? How can they 

 be distributed from one place to another, as from orchard 

 to orchard, since only the males have wings ? 



Drawings suggested. 



a. A single aphis as seen with hand lens. 



i. Various scale bugs as seen with a hand lens. 



c. Twigs showing the distribution and nrrabers of 

 scale bugs. 



WATER BUGS AND BEETLES 



Water Bugs 

 Materials. 



Water bugs and beetles of several species in small 

 aquaria covered with a wire net. 



Observations. 



1. .With what legs does the bug swim? Describe their 

 appearance and tell how used and how fitted for this use. 

 Which legs are not used in swimming ? 



2. Remove the bug from the water for a moment to test 

 other methods of locomotion, as jumping, crawling, flying. 

 What do you discover ? 



3. Watch the bug as it gets a fresh supply of air, and 

 describe the process. Where is the air stored for use when 

 under water? Does the bug sink or rise when it stops 

 swimming ? Why ? 



4. Identify the bug's mouth parts. What is their ap- 

 pearance and probable manner of use ? How are the fore- 

 legs fitted for grasping food ? 



5. What is the shape of the body ? What is the position 



