666 



AN INTRODUCTION TO ENTOMOLOGY 



of covering its body by attaching to it bits of vegetable matter, so 

 that it is masked beneath a tiny heap of rubbish. The wings of the 



adult are of a delicate pale 

 green color crossed by two 

 lines of a lighter shade ; the 

 face is green; and the ab- 

 domen is not marked with 

 pink and white ocellate 

 spots, as is the case in cer- 

 tain allied species. 



Subfamily 

 ACIDALIIN^ 



The members of this sub- 

 family are most easily rec- 

 ognized by the venation of 

 the hind wings (Fig. 821). 

 In these veins Sc+Ri and 

 Rs coalesce for a short dis- 

 tance near the beginning of 

 the second fourth of the 

 discal cell and then diverge 

 rapidly. The greater num- 

 ber of our common species 

 are of medium size, with 

 whitish wings crossed by 

 from two to four indistinct 

 lines, and with the head 

 black in front ; some are pure 

 white, and others are brown marked with reddish lines. Eighty-six 

 species are now listed from this country. 



The chickweed geometer, Hcemdtopis gratdria. — This little moth 

 (Fig. 822) is very common in our meadows and gardens during the 

 summer and autumn months. Its wings are reddish yellow, with the 

 fringes and two transverse bands pink. It is found from Maine tc 

 Texas. The larva feeds on the common chickweed, Alsine media. 

 The sweet-fern geometer, Cosymbia Imnendria. — This moth is 

 grayish white, with three rows of black dots extending across the 

 wings, one marginal, one submarginal, and one near the base of the 

 wings; near the center of each wing there is a small reddish ring. 

 The moth has a wing expanse of from 20 to 25 mm. The larva is 

 common on sweet-fern, Comptonia; it also feeds on birch. 



Fig. 820. — Wings of Dichorda iridaria. 



Subfamily LARENTIIN^ 



In this subfamil}^ the branches of radius of the fore-wings anasto- 

 mose so as to form one or two accessory cells, this anastomosis involv- 



