FIELD BOOK OF INSECTS. 



IX) ; the real jaws are attached near the base of this lip. 

 Odonata have incomplete metamorphosis but the pre- 

 adult stage, although active and showing wing cases, does 

 not at all resemble the adult, differing in but little except 

 size and the presence of wing-pads from its appearance 

 when newly hatched. About 300 species are known in the 

 United States. Bulletins 47 and 68 of the New York 

 State Museum give technical keys by Needham for most 

 of the species of New York as well as details concerning 

 the curious sexual organs and other matters of interest. 



ZYGOPTERA 



This suborder includes the Damsel-flies, those Odonata 

 whose young breathe by means of three leaf-like gills 

 placed at the hind end of their slender body; the adults, 

 when at rest, hold the wings edge up and parallel with the 

 body (see Lestcs, Plate IX). They are not as strong 

 fliers as are the "dragons," and they are more frequently 

 seen flying tandem. In fact, a male often grasps with the 

 pincers on the end of his body the thorax of a female and, 

 flying in front of her, accompanies her on the egg-laying 

 excursions, even going under the water with her when she 

 descends to place eggs inside the stems or leaves of sub- 

 merged plants. It seems to me that the males are of real 

 assistance on such occasions: the legs of Odonata are not 

 well fitted for walking so that it is difficult for them to 

 crawl up through- the water's "film" (surface tension); 

 the joint efforts of both sexes gets the male through and 

 he then uses his wings to pull the female out. 



As will be seen in Plate X, only the male 

 Hetaenna 

 americana Ruby-spot is jeweled. Adults are to be 



found late in the season, fluttering about 

 streams or clustered on the overhanging branches. The 

 young cling to plants growing in the current or, sometimes, 

 to those along the edge of large ponds. 



The members of this large, widely dis- 

 tributed genus (Plate IX.) are usually 

 abundant in marshes and about shallow pools which 

 contain standing vegetation. Needham has noted that 



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