336 Forty-fourth Report of the State Museum 



proper, in his late message, to call public attention to it, that, 

 if possible, it may not be permitted to extend over the state, and 

 other states of the Union. The insect is the Ocneria dispar of Lin- 

 nseus, popularly known in its winged stage, as the Gypsy moth. It is 

 an old pest of European countries — more particularly perhaps in 

 Germany than elsewhere, where at times its caterpillar has stripped 

 the foliage from entire forests. It is one of the kind known as polypha- 

 gous or having a great number of food-plants. Hardly any shrub or 

 tree, whether fruit or forest or ornamental is rejected, and garden 

 vegetables and other products are also eaten by it. It is evidently 

 adapted to a very broad distribution, occurring as it does, throughout 

 Europe, Northern and Western Asia, and in Japan. 



It was accidentally introduced in the United States in the year 1869, 

 by an entomologist, Mr. L. Trouvelot, then living near Glenwood, 

 Medford, Mass., who was engaged in experiments with the production 

 of cocoons suitable for silk manufacture, from our native silk worms 

 and a few foreign species. From some cocoons of the Gypsy moth, 

 brought over by him, the winged insects emerged, and a few chanced 

 to escape. Their progeny, adapting themselves to the conditions pre- 

 sented, have continued to increase from that time onward, until they 

 have become thoroughly naturalized. Fortunately, the species is 

 single-brooded; the female does not deposit many eggs, and its 

 heavy abdomen disinclines it to extended flight. Hence it is, that 

 although twenty years have passed since its colonization, the area 

 of distribution which it has appropriated and now holds, is limited 

 to an ellipse of about a mile and a half by a half-mile in extent, 

 in Medford — a few miles northwardly of Boston. But within 

 this area, it appears, from the report of Professor C. H. Fernald, 

 Entomologist of the Massachusetts Agricultural College and of the 

 Hatch Experiment Station, to have displayed a remarkable voracity. 

 In the Special Bulletin of the Station for November, 1889, devoted to 

 the insect, it is said to have " multiplied to such an extent as to cause 

 the entire destruction of the fruit crop and also to defoliate the shade 

 trees in the infested region" — that above named. That an insect 

 capable of such destructiveness, and with such an European history 

 attached to it, should be promptly met and exterminated while prac- 

 ticable in its present limited area of occupation, will be conceded by 

 all. It is reported by the press, that an appropriation from the state 

 legislature has been asked for the purpose. Professor Fernald 

 expresses his confident belief that "if every tree and shrub in the 

 infested region in Medford be thoroughly showered with Paris green 

 in water, soon after the hatching of the eggs in the spring, the young 



