138 



Marvels of the Universe 



Pholo (.;;] 



[E. Step, F.L.S. 



THE GIANT SILR-MOTH. 



The female molK is here shown of tfie natural size. A few of her: eggs may be seen on the branch near the lower 



edge of the picture, 



US too far. Especially is this the case when we attempt to introduce animals and plants into a new 

 country. Some years ago a Swiss entomologist who was settled in the United States engaged in 

 a series of experiments in breeding moths which he thought might be useful as silkworms. Among 

 others, he received some eggs of the European Gipsy Moth, and these were blown out of the window 

 into his garden ; and the insect succeeded in establishing itself in the neighbourhood, and became 

 a terrible pest, costing thousands of dollars annually in vain attempts to exterminate it. 



When an injurious insect is introduced into a new country, it generally leaves its natural 

 enemies behind, and is therefore enabled to multiply for a time without a check, if general conditions 

 are favourable to it. On the other hand, conditions may not be favourable, and it will then dis- 

 appear of itself. The Gipsy Moth formerly inhabited England, but was almost confined to the Fens : 

 and when they were drained it disappeared, like various other insects. But though abundant every- 

 where abroad, and recently so terribly destructive in America, it was never generally common in 

 England, and even when introduced, has died out more than once, though amid what appeared to 

 be favourable conditions. There seems to be something in our climate inimical to this particular 

 insect ; but its introduction into this country has now, very properly, been forbidden, in common 

 with several other dangerous insects which have been proscribed. 



Several other species greatly resembling the Cecropia Moth, but differing somewhat in colour, 

 are found in various parts of the United States, Canada and Mexico, to which thej' are restricted. 



