170 The Farm Woodlot 



The gipsy moth 



Of all the insects which have infested the trees of the 

 United States, the gipsy moth has done the most damage 

 and most stubbornly resisted all attempts at control. It 

 was brought to this country from Europe in 1868 in con- 

 nection with some silk-producing experiments. It es- 

 caped from captivity in Massachusetts and gradually 

 increased in numbers till the state was obliged to at- 

 tempt its extermination in 1890. It spread over a large 

 portion of Massachusetts and invaded New Hampshire, 

 Maine, Connecticut and Rhode Island. These states 

 have spent several million dollars in combating it, but have 

 not yet been able to exterminate it. 



The moth has a wing spread of 2\ inches, and is a dusky 

 white with blackish blotches and streaks. The eggs, four 

 or five hundred of them, are laid in July and August 

 directly on the bark of trees or on fences, walls, and the 

 like. They form an irregular oval mass, f by 1^ inches, of a 

 yellow or dark creamy color from the hairs or scales from 

 the body of the female. This color is distinctive. The 

 eggs hatch about May 1, and the swarm of young cater- 

 pillars usually become full grown by midsummer. The 

 mature larva has a dusky or sooty colored body. Along 

 the back, counting from the head, which is marked with 

 yellow, is a double row of six pairs of red spots. It 

 frequently attains a length of 3 inches. They become 

 full grown during July, usually about the first. Injury 

 occurs in May and June, increasing as the caterpillars grow. 

 When fully grown, usually in July, the caterpillar spins 

 a few silken threads for support, casts its skin and changes 



