The Moths and Butterflies 



389 



For one hundred and fifty years the peach, an imported plant, has suffered 

 in this country from the ravages of this native pest. One Sesian species, 

 Sanninoidea exitiosa (Fig. 554) is 

 the peach-tree borer of the eastern 

 states, and another, closely related, 

 S. pacifica, works equal injury in the 

 Pacific states. In both species the 

 eggs (Fig. 555) are deposited on 

 the trunk of the tree near its base, 

 in July and August in the East, in 

 April and May in California, and 

 the young larvae (Fig. 556), hatching 

 after a week or ten days, immedi- 

 ately bore in through the outer 

 bark and begin feeding on the 

 live inner bark. When winter 

 comes they cease feeding in the 



East at least and hibernate quies- FlG : 55*- Diagram showing venation of wings 



of bag-worm moth, Thyridopteryx ephe- 

 meraformis. cs, costal vein; sc, subcostal 

 vein; r, radial vein; m, medial vein; c, 

 cubital vein; a, anal veins. 



cent, being now about half-grown. 

 In the spring they become active 

 again, feed and grow rapidly, and 

 by summer are ready to pupate. 

 sc r/ 



Pacifica begins pupating in California 

 in February. For this they leave 

 their burrows, come out to the 

 surface of the bark, spin about 

 themselves a thin silken cocoon 

 and change (Fig. 557). The 

 pupal stage lasts about three 

 weeks, when the moths issue. 

 The clear-winged male moths, 

 expanding i inch, are deep 

 steely-blue, with small golden- 

 yellow markings on head and 

 thorax and abdomen; the larger, 

 heavier-bodied female, expanding 



a a a "* i finches, has a broad orange band 



FIG. 553- Venation of a Pyromorphid, Pyro- across the abdomen in the fourth 

 morpha dimidiata cs, costal vein; sc, sub- Qr fifth segments, and has the 

 costal vein; r. radial vein; m, medial vein; 



c, cubital vein; a, anal veins. (After Com- front wings covered with blackish 



stock; enlarged.) sca l es (Fig. 554). The remedy 



for this pest is the application, by painting on, of gas tar to the basal 



part of the tree-trunk just before the flying and egg-laying time of the 



