ENTOMOLOGY IN OUTLINE LEPIDOPTERA. 71 



of all the butterfly tribe. It was imported from the Mediterranean 

 region into Canada about the year 1868, and since that time has spread 

 all over the American continent. It will be found in swarms over 

 cabbage patches, alfalfa fields, and other sections, in which it finds its 

 food plants, until the fields sometimes have the appearance of being in 

 a snow storm. Its larva is the com- 

 mon green cabbage caterpillar. In 



FIG. 63. Small white cabbage butterfly 

 Larva of Picris brassiae. (Pieris rapx). 



connection with the cabbage whites, we often find a bright yellow but- 

 terfly, known as the sulphur yellow. These belong to the genus Colias 

 and are very common in alfalfa fields, as the 

 larva? feed upon clover. It is a green worm, 

 verv similar to the cabbage-worm, and so 



FIG. 64. Larva of Piens rapx. 



nearly the color of its food plant as to be 



difficult to find. In this State it feeds largely upon alfalfa, and while 

 it does some damage to this crop, can not be regarded as a very 

 serious pest. 



Family Hesperiidse (Skippers). This family is of little economic 

 importance to us. The genus Megathymus is said to have the habit, 

 in its larval stage, of burrowing in the underground stems of the yucca, 

 and. therefore, is somewhat of an anomaly among butterflies, as it is the 

 only one which works beneath the surface. The family is interesting 

 in the possession of certain characteristics which seem to connect the 

 butterflies with the moths. Members of this family are small, with 

 stout bodies, quick and powerful in flight, and have a peculiar jerky 

 motion, from which their common name is derived. They have six 

 well-defined feet in both sexes, and in their metamorphoses weave a 

 light cocoon of a few silk threads, in this, as in many other respects, 

 approximating the moths. 



In North America alone there are over six hundred and fifty species 

 of butterflies, but all belong to one or another of the families named. 



Suborder HETEROCERA. (Moths.) 



We now come to the second and' more important division of the order 

 Lepidoptera, the Heterocera, or moths. The species included under 

 this division are far more numerous and of greater importance in every 



