SILKWORM MOTHS. 



61 



with white and then black, running across all the wings. The caterpillar is yellow, greyish-blue, or 

 green, according to age, and spotted with black. When half-grown it becomes studded with long 

 white tubercles, which secrete a waxy powder. It forms a cocoon resembling brown paper, folded in 

 a leaf of the tree, which is connected with the branch by a silk riband, so that there is no danger of 

 the cocoon falling from the tree when the leaf dies. This insect, which is a native of China, feeds on 

 Ailanthus glandidosa, a naturalised tree, is very easily reared, and has been introduced into England, 

 and many parts of the Continent, and has 

 become wild in some places. But as there 

 are great difficulties in successfully winding 

 the silk, speculators have rarely attempted 

 to rear it on a sufficiently large scale to test 

 its actual value as an article of commerce. 



A great deal of the silk which is used 

 in Japan is produced by the Oak-feeding 

 Silkworm (Anthercea yamamai), which 

 yields a large and beautiful green cocoon 

 of excellent quality. The Moth is a large 

 yellow insect, measuring about seven inches 

 across the wings, which are narrower than 

 in the genus Attacus. In the middle 

 of each wing is a round transparent 

 spot. The Japanese Government long re- 

 served the monopoly of this insect to 

 Japan, its exportation being prohibited on 

 pain of death. But notwithstanding this, 

 eggs were smuggled out of the country 

 from time to time, and there is now no 

 restriction on their exportation. Never- 

 theless, Europe has not yet profited by the 

 introduction of the insect, for although 

 great hopes were based upon it, it is very 

 difficult to rear, and rapidly degenerates in 

 Europe. The cause of its failure has not 

 yet been discovered. Several other closely- 

 allied species are used for the production 

 of silk. Among these is Anthercea 

 pernt/i, a Silkworm which feeds on the oak 

 in North China ; and Anthercva mylitta, 

 the Tusseh Silkworm, a common Indian 

 insect, which yields a rather coarse-looking silk, which requires to be carded, for it cannot be wound, 

 but which is so durable that a dress made of it frequently descends from mother to daughter, as it 

 takes more than one lifetime to wear it out. 



Several of the Moths of this family have long tails on the hind wings. These are not mere pro- 

 jections, as in many Butterflies, but are more like prolongations of the wings themselves. In the 

 genus Actias all the species are tailed, and are of a green or yellow colour, with an eye on each wing. 

 They expand from three to six inches, and most of the species are found in the East Indies, though 

 single species are met with in Spain, Natal, Madagascar, and North America. The genus Eudcemonia 

 includes a few smaller insects, of a brown or yellow colour, found in Africa and South America ; and 

 although they do not measure more than about three inches across the wings, the tails alone are 

 nearly six inches in length in some species. 



The only British species belonging to the family Satiirniidce is the well-known Emperor Moth 

 (Saturnia carpini). It measures between two and three inches across the wings, which are grey in 

 the female, whereas the fore wings of the male are reddish-brown, and the hind wings rusty yellow. 



CATERPILLAR, COCOON, AND MOTH OF BOMBTX MORI. 



