XI 

 LEPIDOPTERA 



Butterflies and Moths 

 This is a large group of very interesting insects. They 

 number perhaps 10,000 species in North America. The 

 group is recognized by the flat scales that densely cover body 

 and wings, and that rub off on the fingers like dust.* 

 The mouthparts of the adults are of a type that 

 is peculiar to the order. They are formed for 

 sucking. That which appears on a superficial 

 examination is a long slender horny tube, that 

 is coiled up when at rest like a watch spring, 

 lying between a pair of hairy or scaly palpi. A 

 very careful examination is needed to discover 

 the presence of the same parts that we have been 

 noting in other insects; for some of these parts 

 are vestigial, and those that are preserved are 

 very much altered in form, 

 have been completely removed from the face, the mouth parts - 

 the vestiges of labrum (I) and mandibles (tnd) appear as 

 shown in our figure; the palpi are seen to arise below the 

 mouth and to belong to the closely applied labium. The in- 

 termediate position of the coiled "tongue" naturally suggests 

 that it is a development from the maxillae. It is, in fact, 

 double — a tube formed by a pair of channelled processes 

 placed together, each maxilla developing half of it. 



* Giving the order its name: lepis, lepidis, scale, and pteron, wing. 



107 



Fig. 44.— 

 Head of a butter- 



When the scales 3L5?*35 



