BEETLES. 



363 



Fig. ilS.—J'i/ropIwrus 

 noctilucus. 



when not illuminated, is yellowish white in color ; but which, when illuminated, gives 

 out a light exceeding in brilliancy that of the Lampyridas. The species of JPyrophorus 

 fly in much more direct lines and give out their light longer and more constantly 

 than do the Lampyi-idse. During flight a luminous organ situated 

 beneath, between the metathorax and first abdominal segment, emits 

 even more light than do the prothoracic lanterns. In Vera Cruz 

 these beetles are so much used as toilet ornaments that they are an 

 article of trade. The Indians capture them by waving 

 about in the air a stick, to which they have attached 

 a burning coal, the light of the coal attracting the 

 beetles in the same way as they are attracted to each 

 other by their own luminosity. They are preserved 

 Fig. 4tU.—Zudius in boxes made of wire netting, are fed each evening 

 with pieces of crushed sugar-cane, and are bathed 

 twice a day in tepid water to keep them in good health. The emis- 

 sion of light by PyropJwrus seems, like that of Lampyridse, to be 

 entirely dependent upon the will of the insect ; when feeding, and 

 during sleep, no light is given off, the greatest intensity of the 

 light being reached during flight and activity. 



Corymbites is a large genus, numbering in the United States over seventy species, 

 and the species vary greatly in form, size, and coloration. C. resplendens, common in 

 northern New England, is shining bronze green with reddish reflections, and is about 

 0.5 of an inch longi C. cylindriformis, a brown species which is quite elongated, 

 varies in length from 0.45 to 0.80 of an inch. 



The genera Athous, Limonius, Melanotus, Elater, and Cryptohypnus are all 

 represented by numerous species in the United States, but many of these species are 

 difficult to distinguish without elaborate descriptions or figures, and little is known of 

 their life history. Melanotus communis is one of the most common species of snap- 

 ping beetles in the northeastern United States; it is brown, 

 pubescent, and about 0.5 of an inch long. 



Alaus ocidatus, not only on account of being one of the largest 

 species of North American Elateridse, but also on account of its 

 peculiar markings, has attracted the attention of almost every 

 beginner in entomology. Its length is a trifle over one and a 

 half inches, and its coloration black and white. The two velvety 

 black spots upon the prothorax, the white rings around these 

 spots, and all the white dots scattered over this insect are pro- 

 duced by scaphoid scales densely set upon the surface. The 

 larvae of A. oculafus live in decaying wood, often in that of 

 apple or pine, and are much broader proportionally than snap- 

 ping-beetle larvas usually are. The length of the larva of this 

 species is 2.5 inches ; its width about 0.4 of an inch across the 

 The head is brownish, the rest of the larva reddish yellow. 

 The species of Chalcolepidius, another genus of large snapping beetles closely 

 allied to Alaus, are partly clothed with scales, as the generic name indicates. C. 

 rubripennis, from southern California, is 1.5 inches long, the striate elytra reddish 

 brown, the black prothorax converted to bronze green by a coating of microscopic 



Fig. 416. — Alaus 

 omlaius. 



middle of the body. 



