602 



NEUROPTERA. 



habits, and any one who can spend the necessarj^ time and 

 patience in rearing them, so as to trace up the diti'erent stages 

 from the larva to the adult fly, and describe and ligure them 

 accurately, will do good service to science. Mr. Uhler states 

 that we know but little of the 3'oung stages of our species, 

 but "the larva and pupa of the Lihelhd<je- may be al\va3's known 

 from those of the ^schnce by their shorter, deeper, and more 

 Tobust form, and generally by their thick clothing of hair." 

 The pupa (Fig. 585, pupa probabl}^ either of vEschna con- 

 stricta or JE. clepsydra) scarcely diflers from the larva, except 

 in having larger wing-pads. It is still active, and preys on 

 other insects. When the insect is about to assume the pupa 

 state the bodj^, having outgrown the larva 

 skin, by a strong muscular effort opens a 

 rent along the back of the thorax, and 

 the insect having fastened its claws into 

 some object at the bottom of the pool, 

 the pupa gradually works its wa}^ out of 

 the larva skin. It is now considerably 

 larger than before. Immediately after 

 this tedious operation its body is soft, 

 but the crust soon hardens. This change, 

 with most species, probablj' occurs early 

 in summer. 



When about to change into the adult 

 fly the pupa climbs up some plant near 

 the surface of the Avater. Again its back 

 yawns wide open, and from the rent our dragon-fl}- slowl}^ 

 emerges. For an hour or more it remains torpid and listless, 

 with its flabby, soft wings remaining motionless. The flOids 

 leave the surface, the crust hardens and dries, rich and varied 

 tints appear, and the dragon-fl}^ rises into its new world of 

 light and sunshine. 



In Agrion and its allies (Agrionina) the antennae are four- 

 jointed, the e^-es are small compared with those of Libellula, 

 and distinct ; the wings are equal, while the abdomen is cjdin- 

 drical and long and slender. In Calox)teryx the wings are 

 very broad and densely reticulated ; the pterostigma is absent 

 in the males, that of the females irregular and areolate ; the 



Fig. 585. 



