64 ELEMENTARY LESSONS ON INSECTS 



shown in figure 70 placed under a water faucet, partly 

 immersed, will keep them. 



Though life after leaving the water is brief, yet there is 

 an additional molt that is not found in other insects — another 

 casting of skin after the adult form is assumed. The first 

 form (subimago) has dull surfaces and the wings bear a fringe 

 of pale pubescence. The ultimate form (imago) has shining 

 surfaces and naked wing borders; also, longer legs and tails. 



LESSON 5 



Mayflies 

 WORK PROGRAM 



1. Collect adult mayflies, if in season; if not, 



2. Prepare dry specimens for study by an overnight stay 

 in a relaxing jar (see p. 186). 



3. Collect nymphs of the flat type from stones or logs in 

 streams (hand picking). 



4. Collect nymphs of the burrowing type from the sandy 

 beds of streams or ponds (use sieve net). 



5. Collect the ordinary nymphs from weedy pools and 

 trash in ponds. (Use any sort of water net.) 



6. Place the flat nymphs in a screen cage (see p. 199) half 

 immersed in a jar of water placed under a water-tap and 

 keep the water flowing. 



7. Keep the live burrowers in a jar having the bottom 

 covered with clean-washed fine sand. 



