OF WASHINGTON, VOLUME XVI, 1914 151 



ON MNEMONICA AURICYANEA WALSINGHAM. 1 



(With Plates IX-XVI) 

 BY AUGUST BUSCK AND ADAM BOVING, Bureau of Entomology. 



Micropteryxauricyanea Walsingham, Trans. Am. Ent. Soc. Phila., p. 204, 1882. 

 Eriocrania auricyanea Walsingham, Entom. Record, London, x, p. 162, 1898. 

 Eriocephala auricyanea Dyar, List N. A. Lep. no. 6018, 1903. 

 Mnemonica auricyanea Meyrick, Genera Insectorum fasc. 132, p. 5, 1912. 



The only published note on the biology of any American species 

 of the superfamily Micropterygidoidea is by Wm. D. Kearfott 

 (Entom. News, p. 129, 1902). He discovered the mine and the 

 larva of what was presumably this species in the leaves of chest- 

 nut, and obtained pupae, but did not succeed in rearing the imago. 



One of the authors (Busck) for several years has collected and 

 si udied these larva? and succeeded last spring in the rearing of a 

 large number of the exquisite "moths. As the American literature 

 on this group is so scant, it is deemed worth while to give the 

 following notes on the life-history, and on the remarkable struc- 

 ture of this American species, although most of the facts have long 

 been known from closely allied European species. 



Mnemonica auricyanea is a small (12-14 mm. alar expanse) 

 strongly iridescent, golden bronze moth, sprinkled with scintil- 

 lating, bright metallic purple scales. The entire life of this little 

 insect above ground, covers but a few weeks. All the rest of its 

 life, more than eleven months, is passed under ground confined 

 within its cocoon. 



The imago issues in April and lays its eggs singly on the open- 

 ing leaves of the Cupuliferse, (chestnut, oak and chinquapin). 

 In May the larva makes a large, bulgy blotch mine in the leaf. 

 It feeds up rapidly, within a week or ten days, falls to the ground 

 :md burrows down into the soil to a remarkable depth in propor- 

 tion to the size of the insect, sometimes as deep as a foot.' It 

 spins a small, very tough, oval cocoon of silk, within which it 

 ]( 'mains curled up as a larva during the summer and fall. During 

 the winter the larva transforms into a most remarkable pupa, 

 which possesses long, arm-like, toothed, movable mandibles, with 

 which it cuts the tough cocoon in early spring and with which it 

 digs its way like a mole up to the surface of the ground, where the 

 imago issues. 



The egg is rather large, oblong, 0.5 mm. by 0.2 mm., soft, white, 

 finely sculptured with minute dots. The female has a short, 

 horny ovipositor and inserts the eggs singly into the young leaf 

 near the edge, generally on the outer half. Dissection of the 



1 Presented at meeting of April 2, 1914. 



