i8 LEPIDOPTERA. 



emerging in May or June, but occasionally appearing in July, 

 August, or November, and, indoors, in December. Only one 

 generation in the year. It is a curious circumstance that 

 those females which appear in the autumn are usually 

 without developed eggs, but it is not clearly established 

 whether these are actually barren, or whether the eggs are 

 gradually developed during hybernation. 



Larva very large and handsome, about five inches in length, 

 solid and thick, when at rest fond of raising its anterior 

 segments and drawing them back into the curious sphinx- 

 like posture so frequent in the group. When in this position 

 it is a very striking object. Usually of a soft green, bright 

 green, dull j^ellow, greenish-yellow, or pale orange yellow, 

 profusely sprinkled with minute black or purplish dots which 

 are rather larger in the dorsal region ; segments five to twelve 

 with oblique lateral stripes, seven in number, of a dull blue 

 or violet colour edged beneath with j-ellow or whitish, 

 extending also to the back and meeting so as to form a 

 dorsal series of V marks ; spiracles purple or black, margined 

 with white ; horn on the twelfth segment of the colour of 

 the body, very rough with points, curiously curved down and 

 then recurved at the tip ; head dull orange. 



But specimens are occasionally found of a dark brown, 

 dull purplish-brown, or even blackish-brown, with the stripes 

 mvTch less distinct, purplish-brown, or in other cases white ; 

 while some of these have the first four segments white clouded 

 with grey ; or brown with broad white stripes and patches, 

 and instead of the usual lateral stripes a broad chain of 

 diamond-shaped, purple-brown cross-bars. Altogether a most 

 singularly coloured and variable larva. 



In July and August, usually in potato fields, devouring the 

 leaves of the potato, and completely stripping one portion of 

 the plant. Feeding usually at night and remaining concealed 

 low down on the stem in the daytime, so that it is not so 

 readily found as would seem probable from its large size. 

 When the potatoes are destroyed by disease it will attack 



