610 



ISTEUKOPTERA. 



to transform it spins an "orbicular pouch of fine white silk 

 of close texture, generally on the trunk of a tree, in chinks of 

 the bark, or among moss. The pupa is quiescent." 



The singular genus Nemoptera is at once recognized by the 

 remarkably long, narrow, linear hind wings which reach far 

 beyond the abdomen. The larva has a remarkably long, 



almost filiform thorax, and was de- 

 scribed under the name of Necro- 

 philus. The species are found in 

 Western Asia and in Northern 

 Africa. 



The genus Hemerobius has mo- 

 niliform antennae, the wings having 

 the subcostal and median veins 

 joined together at the apex, and the 

 costal space of the anterior wings 

 is broader at the base, with a re- 

 current forked vein ; the transverse 

 series of venules are gradate (like 

 a pair of steps) . We have found in 

 Maine a larva (Fig. 599, tergal and 

 side view) of this genus on the bark 

 of a birch tree in October, where it 

 was seen preying on Aphides, and 

 had covered its abdomen with the 

 empty skins of its victims, forming 

 a thkk mantle as seen in the figure. 

 Hemerobius alternatus Fitch is white 

 or yellowish, varied with fuscous, 

 with tawny hairs. According to 

 Fig. 597. Fitch it is found upon pine and 



hemlock bushes. H. occidentalis Fitch has hyaline wings, not 

 mottled as usual with smoky dots or clouds, but adorned with 

 two faint parallel lines ; it expands .38 of an inch. I have 

 raised specimens, referred -to this species by Dr. Hagen, 

 which occurred in the pupa state (Fig. 600), in considerable 

 numbers under a cloth wrapped around a pear tree in a 

 garden in Salem. The cocoon is oval, cylindrical, dense, and 

 surrounded by a much thinner mass of silk more globular 



