58 



ELEMENTARY LESSONS ON INSECTS 



in the big blue and green darner dragonflies, but it 

 is wanting in the skimmers. 



With a damselfly in hand, note: 



1. The differently shaped head and wider spacing of the 

 compound eyes. 



2. The slenderness of the body and the greater obliquity 

 of the thorax. 



3. The similarity of fore and hind wings. 



4. In the male the four appendages (two 

 pairs) instead of three at the tip of the 

 abdomen. 



5. In the female the sharp-bladed ovi- 

 positor that is used for cutting holes for 

 eggs in the stems and leaves of green 

 plants. 



b. The Nymph 

 With a dragonfly nymph in hand note: 

 I. In the head. 



1. Short antennae, less slender than in the 

 adult. 



2. Compound eyes, less expanded than in the adult. 



3. Sharply toothed jaws of the same carnivorous type. 



4. A very remarkable grasping lower lip that is hinged in 

 the middle and folded backward beneath the head. 

 When closed its tip rests against the lower part of the 

 face, but it can be thrust far forward like an arm for 

 grasping prey, and its tip is armed with hooks and 



Fig.20.— The nymph 

 of the damselfly, (Enal- 

 lagma signatum verlic- 

 alis). 



