72 



AA^ ECONOMIC ENTOMOLOGY. 



or false-neuroptera. While they are not directly followed in the 

 classification by the true neuropterous series, yet for convenience 

 they may be so arranged here, and not entirely without reason, 

 because they are descendants of the same stock. 



Order NEUROPTERA. 



As this term is now limited it includes only those ner\x- 

 or net-winged forms with complete metamorphosis in which 

 the biting mouth parts are well developed and not prolonged. 

 The thoracic parts are large, frequently the prothorax is dis- 

 tinctly separated and square, and the entire insect is somewhat 

 flattened. 



Of this type are the large forms like Corydalus 2,ndChaiiliodes, 

 and the peculiar Raphidia found on the western coast, members 

 of the family SialidcB. The head is large and broad, the mandi- 

 bles well or, as in the male Coiydalus, even enormously developed, 

 the antennae long and many jointed ; in Chauliodes pectinated. 

 The prothorax is always distinct, square or oblong, in Raphidia 

 very long and narrow, the other thoracic segments w^ell developed 

 and loosely held together. The abdomen is soft in texture, and 

 as a whole the forms appear loosely jointed. The broad wings 

 he nearly flat on the back and much exceed the tip of the ab- 

 domen, the hind pair being partially folded at rest. The eggs 

 of Corydalus are laid in masses on leaves or sticks, coated with a 

 water-proof secretion, and from them hatch flattened six-footed 

 larvae, which live under stones or other shelter on the bottom of 

 running streams. They are furnished with gill tufts, through 

 which they obtain oxygen, and prey on whatever insects or lar\^ae 

 may come within their reach. In turn they are preyed upon by 

 fishes, and the lar\^ae of the Corydalus corjiutus, or ''dobson," 

 make excellent bait, being locally known as " hellgrammites. " 

 When full-grown they come to the edge of the stream and, under 

 stones or other shelter, change to quiescent pupae, in which aU 

 of the limbs are free and the form of the future adult is fully 

 shown. 



The species of this family are interesting, but of no sort of 

 economic importance. 



Not so the next family, the Hemerobiidcs contains numer- 

 ous species of interest, all of them predaceous and beneficial to 



