Division of Entomology. 



C. H. Fernald, 



' A DANGEROUS INSECT PEST IN MEDFORD. 

 The Gipsy Moth. {Ocneria dispar L.) 



Ou the 27th of hist Juue. during 1113- absence in Europe, several 

 caterpillars were received at the Station, from Hon. William R. 

 Sessions, Secretary of the Board of Agriculture, with the request 

 for information as to what they were, and the best methods of 

 destroying them. These caterpillars were brought into the Secretary's 

 office by Mr. John Stetson of Medford, Mass., who stated that they 

 were very destructive in that town, eating the leaves of fruit and 

 shade trees. Mrs. Feruald, who had charge of the Entomological 

 work during my absence, determined the insect to be the Gipsy-moth 

 {Ocneria cUs2)ar Linn.) of Europe, but as the moths were emerging 

 and laying their eggs for next year's brood, there was nothing to 

 recommend at that time except to destroy the motiis and their eggs 

 as far as possible, and prepare for the destruction of the caterpillars 

 when they first appear next spring. 



FIRST IMPORTATION INTO AMERICA. 



There is a statement in the 2d volume of the American Entomolo- 

 gist, page 111, published in 1870, and also in Riley's 2d Missouri 

 Report on Insects, page 10, that ''only a year ago, the larva of a 

 certain Owlet moth {Hypogymna dispar), which is a great pest in 

 Europe both to fruit trees and forest trees, was accidentally intro- 

 duced by a Massachusetts entomologist into New England" 



These are the only notices I have thus far been able to find of the 

 introduction of this insect into America. Mr. Samuel Henshaw and 

 Dr. Hagen of Cambridge have both informed mo that the entomolo- 

 gist who introduced this insect was Mr. L. Trouvelot, now living in 

 Paris, but at that time living near Glenwood, Medford, where he 

 attempted some experiments in raising silk from our native silk 

 worms, and also introduced European species for the same purpose. 

 Dr. Hagen told me that he distinctly remembered hearing Mr. 

 Trouvelot tell how the\ escaped from him after he had imported them. 



It seems, then, that this was an accidental introduction, but that 

 they have now become acclimated, and are spreading and doing so 

 much damage as to cause very great alarm. 



