THE CABBAGE PLUSIA : FOOD-PLANTS. gi 



the "measuring worms " or "geometers " of the Geoinetridce, as repre- 

 sented in the figure; butunUke most of the geometers, they are tapering, 

 and not cylindrical throughout. This motion is the consequence of 

 their being unprovided with prolegs on the sixth and seventh segments 

 — having only three pairs of abdominal legs instead of the usual num- 

 ber of five. , 



Pxipa and moth. — The chrysalids or pup?e into which the larv^ 

 transform are contained within loosely-spun silken cocoons, permitting 

 the pupae to be seen through the threads, as shown at h. Several of 

 the larvae received were spinning their cocoons October 25th, while 

 others were apparently but about half-grown. The pupse are of a light 

 yellowish or green color, with a projection on the central portion of the 

 lower side, indicating the unusually long proboscis of the moth, for 

 which provision is made in its extended case. 



The front wings of the moth are dark grey, almost brown ; the indis- 

 tinct transverse lines are pale yellowish ; the more conspicuous mark- 

 ings are two small silvery spots near the center of the wing, either 

 united or close together, of which the outer one is oval and the inner 

 U-shaped. The hind wings are smoky outwardly, and yellowish toward 

 the base. The expanse of wings is about one inch and a half. 



The male moth shows a peculiar feature in two tufts of fawn-colored 

 hairs, which spring from the sides of the abdomen behind the middle, 

 and meeting on the back. In the figure of the moth, at c, this feature 

 has been given unusual prominence, in comparison with the examples 

 seen by me. 



For the detailed description of the moth, which might be required 

 for its separation from some closely resembling species, when captured 

 elsewhere than in connection with its larva or general food-plant, refer- 

 ence may be made to its original description in the 2d Missouri Report, 

 pages II I— 12. 



Food-Plants. 



The insect has become a well-known cabbage pest, and its specific 

 name indicates its favorite food-plant, upon which it usually occurs, but 

 it is far from being confined to the cabbage. Its list of food-plants is 

 being continually extended as the result of further observations, and 

 already it embraces kale, turnip, tomato, lettuce, celery, mignonette 

 {Reseda), dandelion (Taraxacum), dock (Rumex), Crepis, Chenopo- 

 dkcni, clover {TrifoUum), German ivy {Senecio scandens), Japan quince 

 {Cydonia jajMnica).* It seems to have developed a particular fondness 



* Riley: Hejit. Comm. A<jricul. for 1883, p. 119. 



