700 



AN INTRODUCTION TO ENTOMOLOGY 



palpi are short.usually but little developed . Themaxillas are present, but 

 they are often weak. The most important features in the venation 

 of the wings are the following; first, the union of veins M2 and M3 

 of the fore wings with cubitus, making it apparently four-branched, 

 in a few lithosiids these branches of media are wanting; and second, 

 the coalescence of the subcosta and radius of the hind wings for a 

 considerable distance (Fig. 885). The extent of the union of these two 

 veins varies greatly in the different genera; it is for at least a fifth, 

 usually a half of the length of the discal cell, but not beyond the end 

 of the cell. 



The larvae of the tiger-moths, except that of Utetheisa, are clothed 

 with dense clusters of hairs. In fact a large proportion of our common 

 hairy caterpillars are members of this family. In some species, 

 certain of the clusters of hairs are much larger than the others, re- 

 sembling in this respect the clothing of the tussock-moths. Most 

 larvae of the arctiids feed upon herbaceous plants, and many species 

 seem to have but little choice of food-plant; but certain common 

 species feed upon leaves of forest -trees. 



The family Arctiidse is divided into three subfamilies, each of 

 which is regarded as a distinct family by some writers. These sub- 

 families can be separated as follows : 



A. Ocelli present, p. 700 Arctiin^ 



AA. Ocelli absent. 



B. Fore wings with raised scale-tufts, p. 705 Nolin^ 



BB. Fore-wings smoothly scaled, p.. 704 Lithoshn^e 



Subfamily ARCTIIN^ 

 The Tiger-Moths 

 The presence of ocelli distinguishes the members of this subfamily 

 from those of the other two. It is the largest of the three subfamilies, 



including about ^125 North 

 American species. The follow- 

 ing are some of the more com- 

 inon representatives. 



The genus Haploa.- — Among 

 ^ ^Z-7' '£]^^ - 1" '"H^^^H ^^® more beautiful of the tiger- 

 ',-/''y''('jg^aL, - -.'^fl^^l nioths is a genus the species of 



which are snow-white or light 

 yellow with the fore wings 



Fig. 886. -Haploa condgua. banded with brown. In most 



species the hmd wmgs are un- 

 spotted and are snow-white, but in some the hind wings are yellow. 

 These moths constitute the genus Hap- 

 loa. A species common in the Atlantic 

 States and represented by Figure 886 is 

 Haploa contigua. The insects of this ' ' 



genus vary greatly in their markings. 



The Bella-moth, Utetheisa bella. — ^ ' /i^5^f\- 

 This is a whitish moth with lemon-yel- ^^k ^j J y i "vx^-" 



low or orange-colored fore v/ings, cross- 

 ed by six transverse white bands, each Fig. 887. — Utetheisa bella. 



