602 



NEUROPTERA. 



habits, and any one who can spend the necessary time and 

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

 from tlie larva to the adult fly, and describe and figure them 

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

 that we know but little of the young stages of our species, 

 but "the larva and pupa of the Libelluloi may be always known 

 from those of tlie ^sclinoi by their shorter, deeper, and more 

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

 The pupa (Fig. 585, pupa probably either of vEschna con- 

 stricta or JE. clepsj'dra) scarcel}- dift'ers 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 bod}^, 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 Avay out of 

 tlie 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, probably occiu-s early 

 in summer. 



When about to change into the adult 

 fly the pupa climbs up some plant near 

 the surface of the water. Again its back 

 3'awns wide open, and from the rent our dragon-fly slowly 

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

 with its flabby, soft wings remaining motionless. The fluids 

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

 tints appear, and the dragon-fly rises into its new world of 

 light and sunshine. 



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

 jointed, the eyes are small compared with those of Libellula, 

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

 drical and long and slender. In Calopteryx 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. 



