MOURNING-CLOAK BUTTERFLY. 289 



are young. As they are gregarious, it is a simple matter to 

 clip off the small twig containing the whole brood of little cater- 

 pillars. When they are larger they can often be dislodged by 

 jarring the branch and destroyed on the ground. Arsenical 

 sprays will kill them, but the presence of fruit makes this 

 remedy undesirable for bearing trees late in the season. 



THE YELLOW-EDGE OR MOURNING-CLOAK 

 BUTTERFLY. 



From Caribou to Kittery the elms in the State are visited 

 by a species of spiny caterpillar which is often present to such 

 an extent as to become a public nuisance. 



Description and Habits. The adult insect (Fig. 30) is a 

 large butterfly with wings of a rich purplish brown bordered 

 on the upper side by a broad margin of buff. A submarginal 

 band of black is decorated Avith a row of blue spots. On the 

 under side the wings have a rough brown appearance which 

 renders the butterfly almost impossible of detection when it 

 alights upon the bark of a tree, its favorite resting place. This 

 butterfly thus affords an excellent example of protective color- 

 ation. It is called in America the "yellow-edge" butterfly, or 

 almost as commonly by its English name of "mourning-cloak." 



Unlike many butterflies, the yellow-edge hibernates over 

 winter in the adult stage and we see this species early in the 

 spring or even in thaw spells during the winter flying about 

 wooded places, or sipping moisture from wet moss and shallow 

 pools. As soon as the leaves start in the spring, the butterfly 

 deposits eggs for the first brood of caterpillars. There are two 

 broods a season and the larvse or caterpillars are found in 

 Maine from June to late September. They occur most fre- 

 quently in this State upon the elm, but they also feed upon 

 willow, poplar, and occasionally,, though not often, upon apple 

 trees. 



The caterpillars (Fig. 28) are formidable looking creatures 

 covered with stiff, sharp spines, the larger of which are 

 branched. The general color is black, flecked with small white 

 dots. The black line which runs along the back is interrupted 

 by eight spots of brick red. 



