CLEAR-WING MOTHS OF FAMILY AEGERIIDAE H 



transparent, heavily scaled at costal margin ; outer margin and fringes 

 black, violaceous. 



Expanse : Male, 18 to 30 mm. ; female, 23 to 32 mm. 



Distribution.- — Canada, United States east of Rocky Mountains. 



Type. — Lost. 



Remarks. — Regarded as of principal economic importaiice among the 

 species of the Aegeriidae, the peachtree borer has been the subject of so 

 many investigations that it would call for many pages merely to cite the 

 published titles, but this is beyond the scope of the present revision of the 

 family. Sanninoidea exitiosa is a North American insect, occurring in a 

 number of varieties and geographical races. Its economic importance is 

 based on the habits of the larvae, which are borers ; originally the species 

 developed in wild species of the Prunus family, such as the cherry and 

 plum, but subsequently and since the introduction of peach and other 

 stone fruits, perhaps 200 years ago, it has transferred its attacks very 

 largely to trees under cultivation, causing enormous injury. Attacks are 

 confined to the base of the tree and to the roots at or below the surface. 



The time of emergence of the imagoes varies in different parts of the 

 continent. Along the coast of Connecticut, New York, and New Jersey 

 it is from early in June through Juh^ ; inland and northward progressively 

 later, from July to September. Southward to Florida and the Gulf States, 

 earlier emergences might be expected, but contrary results have been 

 recorded. Inspection of orchard trees in Florida in April and May re- 

 vealed mostly immature larvae, half grown or smaller. From Fort Valley, 

 Ga., O. F. Snapp reports 75 percent of the moths as emerging in Sep- 

 tember, some during August, others in October, and one record as late as 

 November 8. The life cycle is 1 year in length, occasionally perhaps over- 

 lapping into a second year. Wintering always occurs in the larval state 

 in the burrow. The moths are da}' fliers, often attracted to flowers. 

 Sexually the moths are remarkably fine examples of dimorphism and of 

 mimicry. 



From the Mississippi Valley westward the males exhibit a gradual 

 broadening of the outer margins on the primaries, and the abdominal seg- 

 ments always are all narrowly banded with pale yellow ; they finally merge 

 with the race harnesii of Colorado. The females run true to type. 



6'. exitiosa apparently has followed the extension of peach cultivation 

 westward to the Rocky Mountains. Minor variations indicate response 

 to climatic changes and probably interbreeding with western races. 



SANNINOIDEA EXITIOSA form FITCHII (Hy. Edwards) 



Aegeria exitiosa var. fitchii Hy. Edwards, Papilio, vol. 2. p. 55, 1882. 



Sanninoidea exitiosa var. fitchii Beutenmuller, Bull. Amer. Mus. Nat. Hist., vol. 8, 

 p. 126, 1896; Mem. Amer. Mus. Nat. Hist., vol. 1, pt. 6, p. 269, 1901.— McDxjn- 

 NOUGH, Check list of the Lepidoptera of Canada and the United States of 

 America, pt. 2, No. 8691, 1939. 



