6 MASS. EXPERIMENT STATION BULLETIN 189. 



reflating larvae was unknown to the entomologists of that section where 

 the insect had been found. This aroused the interest of the senior author, 

 who had early recognized the serious nature of the pest. He accordingly 

 collected pupae from infested cornstalks in the field during the month of 

 July, 1917, from which the adults emerged early in August. 



Identifying the Species. 



To secure the identification of the species concerned. Dr. C. H. Fernald's 

 extensive collection of both native and exotic moths was available at 

 Amherst, Mass. An examination of his European collection revealed 

 specimens of both male and female Pyralid moths, identical with those 

 reared from the infested cornstalks in eastern Massachusetts. These 

 European specimens had been determined by Mr. E. L. Ragonot, a French 

 lepidopterist, as Pyrousta mtbilalis Hiibner. 



Specimens of the moths reared in Massachusetts were also submitted 

 to Dr. H. G. Dyar of the United States National Museum at Washing- 

 ton, D. C, who gave the same identification, stating that it was a com- 

 mon and very destructive pest of various wild and cultivated plants in 

 the Old World. 



A Previous Record in Massachusetts. 



Prior to 1917 this insect had never been reported as occurring in the 

 United States, although the following supplementary facts should be 

 recorded. During August, 1916, specimens of dahlia stems infested by 

 lepidopterous larva^ were sent to the Massachusetts Agricultural Experi- 

 ment Station from three localities near Boston, Mass. (Medford, Everett 

 and Lynn). Adults were bred from this material, but their identity was 

 not discovered nor their significance realized at the time. Later, however, 

 the senior author determined these adults as being identical with the 

 P. nubilalis bred from corn in 1917. Thus P. nubilalis was first bred in 

 the United States in 1916, although its identity was not known until 

 adults were bred from corn in 1917. 



Preliminary Investigations. 



As soon as this pest was found to be of foreign origin, and its potential 

 menace to American agriculture realized, its presence became of more 

 than local importance, and a survey was made in eastern Massachusetts 

 during the latter part of September, 1917, to roughly determine its dis- 

 tribution and any other pertinent facts bearing on the insect, and the 

 results of this preliminary survey were published by the senior author (IS) 

 in December, 1917. At this time it was found that the insect had estab- 

 lished itself in an area covering approximately 100 square miles, im- 

 mediately north and northwest of Boston, Mass., and that the towns 

 at the mouth of the Mystic River were more generally infested than the 

 others. In this section are several cordage factories which import hemp 



