676 



AN INTRODUCTION TO ENTOMOLOGY 



with lines or stripes of yellow or white. Owing to the gregarious 

 habits of these larvas they can be easily collected from the trees they 

 infest. 



All the species that we have studied agree in being single-brooded, 

 the moths appearing in midsummer; the eggs are laid in a cluster 

 on a leaf; the larvag are conspicuous in August and September. In 

 some of the species the larvae have the curious habit of leaving the 

 branch upon which they are feeding when the time to molt arrives, 

 the whole colony gathering in a large mass on the trunk of the tree, 

 where the molt takes place. The pupa state is passed in the ground, 

 in a very light cocoon or in none at all, and lasts about nine months 

 ill the species that we have bred. 



The white-tipped moth, Synimerhta dlbijrons. — This oeautiful 

 moth, which is quite common, can be easily recognized by the ac- 

 companying figure (Fig. 842, a) ; the 

 white patch, which extends along the 

 costa of the fore wing for half the 

 length from the tip, being very char- 

 acteristic. The larva (Fig. 842, b) is 

 quite common in the autumn on 

 leaves of oak. It is known as the red- 

 humped oak-caterpillar ; it is smooth 

 and shining, with no hairs; along 

 each side of the back there is a 

 yellow stripe, and between these, on 

 the back, fine black lines on a pale lilac ground; on each side below 

 the yellow stripes there are three black lines, the lowest one just 

 above the spiracles. The head is orange-red ; and there 

 is an orange-red hump on the eighth abdominal seg- 

 ment. 



The two-lined prominent, Heterocdmpa bilinedta. — 



The larva of this 



Symmerisla albifrons. 



Fig. 842b. — Symmerista albtfrons, larva. 



species(Fig.843) 

 is much more apt 

 to be observed 

 than the adult. 

 It is common in 

 the latter part of 



the summer and in early autumn, feeding on the leaves of elm, beech, 



and basswood. It measures when full-grown about 3 7 mm. in length. 



Its ground-color is usually green, but 



sometimes claret-red. There is a pale 



yellow stripe along the middle of the back, 



and on each side a stripe of the same color. 



The course of these side stripes is very 



characteristic; passing back from the 



head, they converge on the prothorax; on 



the mesothorax and metathorax they are 



separated from the dorsal line only by a narrowband of red or purple; 



on the first abdominal segment they diverge to the lateral margin of 



Fig. 843. — Heterocampa 

 lineata, larva. 



bi- 



