Sphingidae 



of which, as examined under the microscope, is seen to be quite 

 different from that which prevails in any other family of moths. 

 The accompanying illustration (Fig. 20) shows this arrange- 

 ment in the case of the common Five-spotted Hawkmoth, 

 (Protoparce qtimquemaculatus). 



The wings are small in comparison with the body. The 

 front wings are very long in proportion to their width, and 

 the costal veins are always very stoutly developed. The tip 

 of the wing is usually pointed, and the margins are straight 

 or evenly rounded, though in some genera, principally be- 

 longing to the subfamily Ambulicince, they have undulated 

 or scalloped margins. The hind margin of the fore wings 

 is always much shorter than the costal margin. The hind 

 wings are relatively quite small. The venation of the wings 

 is characteristic. The primaries have from eleven to twelve 

 veins, the secondaries eight, reckoning the two internal veins, 

 veins i a and i b, as one. Veins eight and seven are 

 connected near the base of the wing 

 by a short vein, or bar. The discal 

 cell is relatively quite small in both 

 wings. There is always a frenulum, 

 though in the Amhiilkince it is frequently 

 merely vestigial. The general style of 

 the venation is illustrated in Figure 21, 

 which represents the structure of the 

 wings of Sesia ianialus Linnaeus. The 

 hawkmoths have prodigious power of 

 flight. A few genera are diurnal in their 

 habits; most of them are crepuscular, flying in the dusk of 

 evening, a few also about dawn. 



The larvse are usually large. There is great variety in their 

 color, though the majority of the North American species are of 

 some shade of green. They usually have oblique stripes on 

 their sides, and most of them have a caudal horn, which in the 

 last stages in some genera is transformed into a lenticular 

 tubercle. In a few genera the anal horn is wanting. The 

 anterior segments of the bodies ot the larvae are retractile. When 

 in motion the body is long and fusiform, but when at rest the 

 head and the anterior segments are drawn back, the rings 



Fig. 21. — Neiiration of 

 wings of Sesia tantalus 

 Linnasus. 



42 



