hawkins] STUDIES OF AQUATIC INSECTS 93 



The net-building caddice worm may be found attached to stones 

 in running water of brooks or attached to dams. This can not be 

 kept for more than a day or two in the ordinary aquarium and 

 so is best studied in the field. 



Method 



The insects should be kept for several weeks so as to allow 

 sufficient opportunity for the children to study their habits. They 

 may be fed once a week on raw meat or mosquito larvae. The 

 children should be encouraged to observe at odd moments out of 

 school hours, as well as during the lesson period. To guide the 

 children's study, the following questions may be written on the 

 board, a few at a time. 



Observations 



Study each insect with reference to the following points : 



i. How does it move? 



Does it have more than one method of moving? How are 

 its legs fitted for swimming? Is its motion rapid or slow? Is the 

 shape of the body such as to help or hinder its motion? Does- 

 it ever leave the water or attempt to fly ? Which insect seems best 

 fitted to rapid motion? 



2. How does it breathe? 



Does it ever come to the surface of the water? What is its 

 position when at rest? How does it secure air? Which can stay 

 at the bottom the longest? Why do caddice worms need to move 

 less than the backswimmers ? 



3. How does it get its food? 



What kind of food is taken ? How is it secured ? 



4. How is it protected? 



How are its wings protected from injury? How is it pro- 

 tected from its enemies? Which insect seems best protected? 



5. What are the important differences between the back- 

 swimmer and some land insect such as the grasshopper? Suppose 

 they should change places? 



What do you consider the most interesting things you have 

 observed about these insects ? 

 Drawings 



Make drawings of the insects while at rest. 

 Literature (for children) 



Lovejoy's "Poetry of the Seasons", pages 37 and 125. 

 References (for teacher) 



Miller's "The Brook Book" ; Comstock's "Insect Life". 



