238 INJURIOUS AND USEFUL INSECTS 



gree, is ready to make good the inevitable deficiencies of local 

 advisers. The defence of the crops against insects and parasitic 

 plants, as well as the best treatment of the land, are now being 

 studied methodically with excellent results. Two cases in 

 which scientific method has been called in to deal with insect 

 attacks on a great scale are worth relating in some detail for 

 the instruction of the English farmer and his advisers. The 

 two cases in question are the Gipsy-Moth plague in Massa- 

 chusetts and the Orange Scale plague in California. 



THE GIPSY-MOTH IN MASSACHUSETTS * 



The gipsy-moth belongs to the same family {Liparidce) as 

 the vapourer, the black arches, or nun-moth (a terrible plague 

 in the pine-forests of Germany), the gold-tail, the brown-tail, 

 and the tussock moths. All agree pretty well in the dissimi- 

 larity of the sexes when adult, in the complex antennae of the 

 male only, the sedentary habit of the female, the hairy larva, 

 and the protective cocoon. Nearly all are indiscriminate in 

 their food. The gipsy-moth is very common in many parts of 

 Europe and Northern Asia, but is almost unknown in England, 

 and is not indigenous to any part of America. 



This pernicious insect was imported into Massachusetts by 

 Professor Trouvelot, of the astronomical observatory at Har- 

 vard, who had some intention of making experiments upon the 

 silk of various moths. The eggs or larvae were accidentally 

 dispersed from Trouvelot's house in Medford about 1868-69. 

 Being aware of the ravages of the moth in Europe he gave 

 warning that it was at large and beyond his control, but neither 

 he nor any public officer took any adequate measures of re- 

 pression. Close to his house was an extensive wood, with 

 abundant undergrowth, and in this the insect established itself 

 without much notice. For ten years little was seen or heard 

 of the escaped moths, but then they rather suddenly became a 

 serious plague in the immediate neighbourhood of Trouvelot's 

 house. The neighbouring gardens and orchards were steadily 

 invaded in spite of the vigorous but unsystematic exertions of 

 the owners. Before long the larvae covered the trees, entered 



• See "Report on the Gipsy-Moth," by Forbush and Fernald (Boston, 

 1896). 



