718 



AN INTRODUCTION TO ENTOMOLOGY 



Fig. 916 

 male. 



■A nisota virginiensis, 



purplish red, or brownish in color, and agree in having the fore wings 

 marked with a white discal dot. The larv'a^feed on the leaves of oak; 

 they are more or less striped and are armed with spines. These in- 

 sects hibernate as pupa?. 



In determining these moths, the student should remember that 

 the two sexes of the same species may differ more in appearance 

 than do individuals of different species but of the same sex. The 

 sexes can be distinguished, as already indicated, by the antennae. 

 The three species can be separated as follows. 



The rosy-striped oak-worm, Anisota virginiensis. — The wings of 

 the female are purplish red, blended with ochre-yellow; they are 



very thinly scaled, and consequent- 

 ly almost transparent; and are not 

 speckled with small dark spots 

 (Fig. 916). The wings of the male 

 are purplish brown, with a large 

 transparent space on the middle 

 (Fig. 917). The larva is of an ob- 

 scure gray or greenish color, witli 

 dull brownish yellow or rosy stripes, 

 and with its skin rough with small 

 white warts. There is a row of short 

 spines on each segment, and two 

 long spines on the mesothorax. 

 The orange-striped oak-worm, Anisota senator ia. — The wings of 

 the female are more thickly scaled than in the preceding species and 

 are sprinkled with numerous blackish dots; 

 in other respects the two are quite similar in 

 coloring. The male differs from that of A. 

 virginiensis in lacking the large transparent 

 space on the middle of the wings. The larva 

 is black, with four orange-yellow stripes on 

 the back and two along each side; its spines 

 are similar to those of the preceding species. 

 The spiny oak-worm, Anisota stigma.- — ■ 

 The female closely resembles that of A. 

 senatorial ^•I'ld as both species are variable 

 it is sometimes difficult to determine to which 

 a given specimen belongs. In A. stigma the 



wings are rather darker and have a greater number of blackish spots, 

 and the hind wings are furnished with a middle band which is heavier 

 and more distinct than in A . senatoria. The male differs from that of 

 the other two species in quite closely resembling the female in color- 

 ing, and in having the wings speckled. The larva dift'ers from the 

 other species of Anisota in having long spines on the dorsal aspect 

 of the third thoracic and each abdominal segment in addition to the 

 much longer spines on the mesothorax. It is of a bright tawny or 

 orange color, with a dusky stripe along its back and dusky bands 

 along its sides. 



Fig. 9 1 7 . — .4 nisota virgin- 

 iensis, iTiale. 



