338 



THE GYPSY MOTH. 



position of the lines and spots are the same as in the males. 

 The fore wings are longer, narrower and more pointed than 

 in the males. The hind wings have a faint discal spot and 

 a subterminal line which is toothed along the outside on the 

 veins, and the cilia have black basal spots between the veins. 

 The antennge and legs are dark brown, but the hair on the 

 femora and tibiae is yellowish white. 



The imago is subject to considerable variation in size. 

 The following table gives the dimensions of the largest and 

 the smallest imagoes of each sex, taken in the field : — 





Expanse 

 of Fore 

 Wings. 



Expanse 

 of Hind 

 Wings. 



Length 



of 

 Body. 



Diameter 



of 

 Thorax. 



Diameter 

 of 



Abdomen. 





mm. 



mm. 



mm. 



mm. 



mm. 



Largest male, 



46 



37 



18 



5 



3 



Smallest male, 



33 



25 



12 



4 



2 



Largest female, 



71 



53 



31 



8 



12 



Smallest female, 



44 



34 



16 



5 



6 



Mr. J. H. Leech, in the Proceedings of the Zoologi- 

 cal Society of London," Vol. LYI, page 630, expresses the 

 opinion that the Japanese gypsy moths, which have been 

 described as distinct species, do not difier from those of 

 Europe, except in size, and he regards them only as forms, 

 and not distinct species. He gives the extremes of size of 

 males and females in Japan and Corea as follows: Ex- 

 panse of wings of largest male, 71 mm. ; smallest male, 

 37 mm. ; largest female, 114 mm. ; smallest female, 48 

 mm." Mr. Leech also gives the size of European examples 

 of the gypsy moth as follows: Largest male, 54 mm.; 

 smallest male, 32 mm. ; largest female, 93 mm. ; smallest 

 female, 42 mm." I have in my collection three males from 

 Pekin, China, which measure 46, 50 and 54 mm., respec- 

 tively, in expanse of wings ; and several male examples 

 from Europe, the largest of which measures 43 mm. and 

 the smallest 37 mm. I can see no difference between the 

 examples from China and those from Europe, except in 

 size. 



