BEETLES. 309 



the mimicry so far as to have yellow spots on the abdominal segments to correspond 

 with the luminous portions of the fire-fly. Other beetles imitate sticks, seeds, and 

 parts of plants. The cocoon of a European weevil ( Clonus scrophularice) resembles 

 very closely the seed-capsules of the species of Scrophularia on which the larva 

 feeds. 



Other common means which beetles employ to escape from their enemies are 

 dropping to the ground and feigning death, a practice of weevils ; use of disagreeable 

 odors and secretions, as is general with lady-birds ; appearing as if about to bite or to 

 sting, or rapid running and flying. 



A few beetles have been made directly useful to man ; indirectly a large number 

 of them benefit mankind. Perhaps the blister-beetles (Meloidse) are most evidently 

 useful to man, since from them are derived the various forms of vesicatory medicines, 

 known under the name of cantharides. In earlier times other beetles were used for 

 medicinal purposes. The larvae of the palm-weevil of tropical America (Rhyncho- 

 phorus palmarum), or of other large palm-weevils, are roasted and eaten as delicacies 

 by numerous tribes in the tropics of both hemispheres. The Cossus, which Pliny 

 says Roman epicures fattened with flour, probably was the larva of Prionus coriarius, 

 a longicorn ; larvae of Prionus, as well as those of other large longicorns, are still 

 eaten roasted in many parts of the world. Beetles of many species are used as orna- 

 ments : fire-flies, imprisoned in gauze or otherwise confined, embellish the evening 

 coiffure of ladies, both in the East and West Indies ; the elytra or whole bodies of 

 brilliant tropical Coleoptera are formed into pictures, are used to trim dresses and 

 hats, are even set in jewelry ; and, in some cases, a beautiful chrysomelid (Chrysochus 

 auratus), common in the eastern United States upon species of dogbane (Apocynum), 

 has helped adorn ladies for evening parties in this part of the world. In China 

 the people sometimes derive amusement from beetles, which they confine in order 

 to watch them fight, in the same way as they confine species of Mantis for like 

 purpose. 



The indirect benefit which man derives from Coleoptera is fully as important as 

 are the dii'ect uses to which he puts them. Thousands of species of beetles prey 

 upon plant-eating insects, others remove refuse and decaying animal and vegetable 

 matter, still others help in fertilizing flowers ; many furnish food to useful birds and 

 fishes, but it is futile to specify further in this direction. 



Few beetles are directly injurious to man ; when they bite it is in self-defence ; but 

 their injuries to crops, forests, fruits, lumber, buildings, furniture, carpets, and books 

 are notorious, and can be best noticed later. 



Beetles are divided into four great groups (Cryptotetramera, Cryptopentamera, 

 Heteromera, and Pentamera), according to the number of segments of their tarsi. 

 This classification is not perfect, in that a few families or genera fall into groups where 

 they would not belong on account of their tarsal characters, but into groups in which 

 they must be included on account of other important characters. The late Dr. J. L. 

 LeConte, an eminent authority on North American beetles, divided the Coleoptera 

 into two parts, the genuine Coleoptera and the Rhynchophora or weevils, but this 

 division has not yet met with general acceptance. 



To the Heteromera are added, in the following pages, the Stylopidae, a family 

 which, according to some authors, forms an order of insects, the Strepsiptera. The 

 Strepsiptera, for they are in all probability a separate order, have from two to four 

 tarsal joints, according to the genus. 



