436 NATURAL HISTORY OF ARTHROPODS. 



rib of the hind-wing near the base, which passes through a loop 011 the under side of 

 the fore-wing, thus holding the two wings together in flight. 



Some of the moths are most gaily and gorgeously colored, while others are ex- 

 tremely plain and subdued in their attire. There is also a great range in size among 

 these insects, from the great owl-moth ( Thysania agrippina) of Brazil, the wings of 

 which expand nearly a foot from tip to tip, down to the smallest mite of a tineid 

 scarcely visible to the naked eye. The moths have a wide distribution, extending 

 from the equator far into the polar regions ; and while some species are quite restricted, 

 being limited to a very small territory, others are found in every quarter of the globe, 

 often in great abundance. 



As a rule the moths are very prolific, some species laying as many as three or four 

 hundred eggs ; and while many give rise to only a single generation in a year, others 

 have two, or in the warmer, temperate, or tropical regions, even three or four in a 

 single season. Some of the species hibernate in the imago state, others pass the win- 

 ter in the egg, and still others in the caterpillar state, either immediately after hatch- 

 ing, or when half or fully grown ; but by far the larger number pass the winter in the 

 pupa state. 



The Iarva3 or caterpillars are composed of thirteen joints or segments, of which the 

 head is the first. They have a pair of legs on the second, third, and fourth segments, 

 and the number of prolegs on the abdominal segments varies in the different families. 

 Some caterpillars are entirely smooth and naked, while others are clothed more or less 



FIGS. 553-555. Larva of moths. 



densely with hairs, spines, bristles or protuberances, and in one family most of the 

 species have a curved, tapering horn on the top of the last segment but one. Many 

 of these spines or tubercles are hollow, and contain a fluid which escapes, giving off a 

 very offensive odor, if the spines are broken. Some species produce a strong, sting- 

 ing sensation if brought in contact with the hand, and even the moulted skins will pro- 

 duce the same unpleasant effect if handled too freely. 



The caterpillars of most moths feed on living plants ; a small number, however, 

 feed on dead material, and a very few are predaceous in their habits. Some confine 

 themselves to the leaves of a single species of plant, others feed on closely related 

 species, while still others are very indiscriminate in their diet, attacking plants which 

 are totally unlike with equal avidity. Some bore in the stems or solid trunks of trees, 

 others attack the fruit only, while still others feed upon the seeds. A few minute 

 species are very destructive to woollen fabrics of all kinds, and feed also on feathers, 

 furs, and even dried plants. Some are especially destructive to grain in storehouses, 

 and others do not hesitate to attack the very food in our pantries. Aside from the 

 few silk-producing species, there is scarcely a single moth in all the world that can be 

 regarded of any direct value to mankind. 



We are far from having a satisfactory classification of the moths, but a division 

 into the following families will answer the purposes of this work : Pterophoridre, 

 Tineiclre, Tortricidaa, Pyralidie, Geometrida3, Noctuidae, Bombycidse, Zygasnidse, JEgeri- 

 adre, and Sphingidae. 



The moths of the small family PTEROPHOKID^E, frequently called feather-wings or 



