72 



THE STUDY OF INSECTS 



Family Sisyrid^e 



The Spongilla-flies 



The Sisyridae include a very limited number of small, smoky brown 

 insects. They are called spongilla-flies because the larvae live as paras- 

 ites in fresh-water sponges, the typical genus of which is Spongilla. 



Family Sympherobiid^e 



The Sympherobiids 



This family includes certain insects which were formerly classed with 

 the Hemerobiidae but which exhibit a type of specialization of the wings 

 that is quite different from that which is distinctively characteristic of 

 that family. 



Family Hemerobiidae 



The Hemerobiids 



The Hemerobiidae include insects of moderate size; in most of our 

 species the wing-expanse is between ^ and | of an inch; in one species 

 of Megalomus it is only \ inch. In most of the species the body is 



Fig. iiq. — Fore wing of Hemerobius. 



brown or blackish and is often marked with yellow; in some the body 

 is pale yellow. The wings are usually hyaline or pale yellowish (Fig. 119). 



Family Dilarid.e 



The Dilaridae is a small family, representatives of which are found 

 chiefly in the Old World. In this family the antennae of the male are 

 pectinate; and the female is furnished with an exserted ovipositor. 



A single rare species, Dllar americdnus, has been found in North Amer- 

 ica; and of this only a single female individual is known of which the 

 body is scarcely £ of an inch in length. 



