30 IKJUBIOUS INSECTS 



two anterior segments, which are usually furnished with 

 such legs in ordinary caterpillars, not having the slight- 

 est trace of any. Consequently they have to loop the 

 body in marching, as represented in the figure, and are 

 true Span worms. Their bodies are very soft and tender, 

 and as they live exposed on the outside of plants, and 

 often rest motionless, with the body arched, for hours at 

 a time, they are espied and devoured by many of their 

 enemies, such as birds, toads, etc. They are also sub- 

 ject to the attacks of at least two parasites and die very 

 often from disease, especially in wet weather, so that 

 they are never likely to increase as rapidly as the butter- 

 flies already described. 



When full grown, this worm weaves a very thin, loose, 

 white cocoon, sometimes between the leaves on which it 

 fed, but generally chooses some more sheltered situation; 

 and changes to a chrysalis (fig. 23, #,) which varies from 

 pale yellowish-green to brown, and has a considerable 

 protuberance at the end of the wing and leg-cases, caused 

 by the long proboscis of the enclosed moth being bent 

 back at that point. This chrysalis is soft, the skin being 

 very thin, and it is furnished at the extremity with an 

 obtuse roughened projection, which emits two converging 

 points, and several short curled bristles, by the aid of 

 which it is enabled to cling to its cocoon. 



The moth is of a dark smoky-gray, inclining to 

 brown, variegated with light grayish-brown, and marked 

 in the middle of each front wing with a small oval spot, 

 and a somewhat U-shaped silvery-white mark, as in the 

 engraving. The male (fig. 23, c,) is easily distinguished 

 from the female by a large tuft of golden hairs covering 

 a few black ones, which springs from each side of his 

 abdomen towards the tip. 



The suggestions given for destroying the larvae of the 

 Cabbage Butterflies, apply equally well to those of this 

 Cabbage Plusia, and drenchings with a cresylic wash will 



