CHAPTER X 

 ORDER ODONATA* 



Fig. 125. — A dragonfly. 



The Dragon flies and the Damselflies 



The members of this order have jour membranous wings, which are 

 finely netted with veins; the hind wings are as large as or larger than the 

 fore wings; and each wing 

 has near the middle of the 

 costal margin a joint-like 

 structure, the nodus. There 

 are no wingless species. 

 The mouth-parts are formed 

 for chewing. The metamor- 

 phosis is incomplete. 



Dragonflies and damsel- 

 flies are very common in- 

 sects in the vicinity of 

 streams, ponds, and lakes; 

 they are well known to all 

 who frequent such places. 

 The dragonflies, especially, 

 attract attention on ac- 

 count of their large size (Fig. 125) and rapid flight, back and forth, over the 

 water and the shores; the damselflies (Fig. 128) are less likely to be noticed, 

 on account of their less vigorous flight. 



Suborder ANISOPTERA f 



The Dragonflies 



The dragonflies constitute a natural division of the Odonata, the sub- 

 order, Anisoptera. The wings of dragonflies are usually extended hori- 

 zontally when they are at rest and the hind wings are as large and often 

 are larger than the front ones. The compound eyes are very large, often 

 occupying most of the surface of the head. In many cases the upper 

 facets of each eye are larger than the lower ones. It is probable that in 

 such eyes the part of the eye with the large facets is for night vision 

 while the part of the eye with the small facets is for day seeing. Most 

 dragonflies appear to have very keen sight for they follow and catch 

 mosquitoes, midges and other small flies while on the wing, much as a 

 hawk swoops downward and captures a weaker bird. But dragonflies are 

 entirely innocent of any harm to mankind. They neither sew up people's 



* Odonata: odous (65ous). a tooth. 



f Anisfiptera: anisos (avuros), unequal; pteron (irrepov), a wing. 



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