CHAPTER IX 

 THE WINGS OF THE NEUROPTERA 



(a) THE MORE GENERAL FEATURES OF THE WIXGS OF THE NEUROPTERA 



The wings of the Neuroptera are membranous and usually furnished 

 with many wing-veins. The two pairs of wings are similar in texture and 

 usually in outline; in some, the fore wings are slightly larger than the hind 

 wings, in others the two pairs of wings are of the same size. The anal area 

 is small in both fore and hind wings; it is rarely folded, and then only 

 slightly so. A distinct anal furrow is rarely developed. Definitive acces- 

 sory veins are usually present, and, as a rule, there are many marginal 

 accessory veins. Intercalar\^ veins are never developed. When at rest, 

 with few exceptions, the wings are folded roof-like over the abdomen. In 

 some cases organs for uniting the fore and hind wings are present. 



In most of the families the radial sector is pectinately branched. In 

 nearly all cases, media is obviously not more than two branched, if accessor}^ 

 veins be not counted; and in those cases where it appears to be three or 

 four branched it may be that this condition is due to a secondary splitting 

 of one or of both of the two primitive branches. In a few members of the 

 order the hind wings are very small and in some they are wanting in one 

 sex. In the family Nemopteridae the two pairs of wings differ greatly in 

 form, the hind wings being very long and narrow; in some members of this 

 family the hind wings are thread-like. 



In the following discussion of the wings of the Neuroptera figures are 

 given of the wings of representatives of all of the recognized families of the 

 order. It was necessar^^ to figure a large proportion of these in order to 

 illustrate the various methods of specialization that are found within the 

 order; and when this was done it seemed worth while to add figtues of 

 representatives of the remaining families, for the sake of completeness, 

 although they presented no difficulties in the application of the uniform 

 terminology of the wing-veins. 



For convenience in making generalizations the families Sis^Tidae, 

 Sympherobiidie, HemerobiidcC, and Dilaridae are referred to as the hemero- 

 biid group of famihes; and the N^Tnphidee, Myrmeleonidas, Ascalaphid£e, 

 Nemopteridffi, and Apochrysidas, as the m^rrmeleonid group. 



This study of the wings of the Neuroptera has been greatly facilitated 

 by the presence in the entomological museum of Cornell University of a 

 large collection of Neuroptera, which has been brought together by Dr. 

 Needham. 



(145) 



