NEUROPTERA 



303 



Fig- 343- — Larva, cocoon with pupa-skin projecting, and 

 adult, of an ant-lion. 



Family MYRMELEONID^ 



The Ant-Lions 



The members of the family Myrmeleonidas are commonly known 

 as ant-lions. This name was suggested by the fact that the larvee of 

 the best-known 

 species, those that 

 dig pitfalls, feed 

 chiefly on ants. 



The adults are 

 graceful creatures. 

 The body is long 

 and slender (Fig. 

 343); the antenucB 

 are short and en- 

 larged towards the 

 end ; the wings are 

 long and narrow 

 and delicate in 

 structure ; they are 

 furnished with many accessory veins, both definitive and marginal, 

 and with very many cross-veins. A distinctive feature of the wings 

 of these insects is the presence of an elongated cell behind the point 

 of fusion of veins Sc and Ri (Fig. 344); this characteristic serves to 

 distinguish this family from the closely allied Ascalaphidas. 



The determination of the homologies of the wing-veins of the 

 Myrmeleonidse was completed only recently. The results of this de- 

 termination are set forth in detail by the writer in his "The Wings 

 of Insects," where they are illustrated by many figures. 



Our native species, as a rule, are not striking in appearance; 

 the wings are hyaline and are often more or less spotted with black or 

 brown marks; iDut certain exotic forms, as those of the genus Pal- 

 pares, are large and have conspicuously marked wings. 



The larvae have broad and somewhat depressed bodies which 

 taper towards each end (Fig. 343). The mouth-parts are large and 

 powerful and are of the piercing and sucking type; they are described 

 on page 282. The pupa state is passed in a spherical cocoon, made of 

 sand fastened together with silk, and neatly lined with the same 

 material (Fig. 343). The silk is spun from the posterior end of the 

 alimentary canal and is secreted by modified Malpighian vessels, as 

 in Sisyra (see page 283.) 



This is a large family including several hundred described species. 

 In his "Catalogue of the Neuropteroid Insects of the United States," 

 Banks ('07) lists fifty-eight species of this family known at that time 

 to occur in our fauna; these are distributed among eleven genera. 



The life-histories of comparatively few of the species are known ; 

 but certain species, the larvae of which dig pitfalls in sandy places, 

 have attracted much attention since the earliest days of entomology. 



