404 Report of the Department of Entomology of the 



comparisons of ge^^talia. 



With these moths the uncus is long and slender, and it is sinuate 

 towards the tip which is acut« and a little hooked. The lateral 

 pieces or claspers are broad and hemispherical, with the apices 

 gently rounded or somewhat acutely rounded according to their 

 positions in the mounts. The sexual parts of the male are sj-mmetri- 

 cal or very closely so, and the general t}-pe of the genitalia of this 

 group of moths is shown in Plate XLIII. 



A study of a goodly series of mounts of padeUus from ha-^-thom 

 and malineUus from apple from difTerent geographical areas reveal 

 no tangible structural differences between them. The lobe or spur 

 at the base of the uncus varies slightly in width and length vriih 

 some indi\-iduaLs, but this variation may also be detected -wnth any 

 assemblage of males from either of these hosts. A comparison of 

 the figures, Plate XLIII. plainly shows that there are no ob%ious dis- 

 tinctions in the more important organs which will bear out these 

 minor differences. 



Considering all differential features, structural as well as super- 

 ficial, it appears that the moths of malinellus do not possess sufficiently 

 diverse values to entitle them to specific distinction and that the 

 specimens bred from hawthorn, cherr\' and apple really constitute 

 a single species. Breeding experiments are now needed to definiteh' 

 settle the status of these two moths, and these we have not under- 

 taken as it did not seem wise to take chances with the insects. We 

 have, therefore, followed the example of European writers, and 

 have treated the two forms as distinct species. 



THE ERMINE MOTHS OX SEEDLINGS. 



ORIGIN OF INFESTATION. 



The stock which has been responsible for the introduction of 

 the ermine moths consists of one-year-old seedlings, which are fre- 

 quently grown in plats near hedge rows, trees or even woodland. 

 Such surroundings are very favorable for the breeding of various 

 destructive pests. The flight of the ermine moths takes place 

 during July and August, and in their excursions some of them have 

 unquestionably made their way to the nm-ser\' blocks in the immediate 

 vicinity and deposited their eggs on the young seedlings, which 

 were subsequently shipped to the Unit^ States. The life history 

 of the insect would indicate this course of events, and since we have 

 become famiUar with their appearance we have collected the egg 

 masses on the stocks aft€r their shipment to this country'. The 

 conditions during 1909 with respect to these pests surrounding 

 some of the foreign nurseries which have been growing seedhngs 



