52 THE CANADIAN ENTOMOLOGIST. 



NEPTICULA POMIVORELLA, Packard; ALIAS MICRO- 

 PTERYX POMIVORELLA, Packard. 



BY AUGUST BUSCK, WASHINGTON, D. C. 



During a visit to Professor Fernald, in Amherst, Mass., last spring, 

 he showed me a Nepticula, bred from Apple, which he had described in 

 manuscript as a new species, but which he afterwards had suspected to 

 be Micropteryx pomivorella, Packard. 



From reading the description and life-history of Packard's species, I 

 felt sure that it was a Nepticula and presumably the same as Professor 

 Fernald's species, and a week after, while studying the collection in the 

 Agassiz Museum, Cambridge, I obtained definite proof that we were 

 right. 



There I found Packard's type — imago and cocoon — in rather poor 

 condition, but easily recognizable as a typical Nepticula and similar to a 

 large series of fine bred specimens in the U. S. National Museum. 



The habit of this species of forming its cocoon on the twigs or the 

 branches instead of descending to the ground, as is rather more common 

 in the genus, makes the cocoon liable to be confounded with that of 

 Coptodisca (Aspidisca) splendoriferella, Clemens, which is also frequently 

 found in numbers on Apple. 



Both have been mistaken for scale insects. 



By a common hand-lens, however, they can be easily separated, as 

 the Nepticula cocoon is made of matted silk, while the Coptodisca 

 cocoon consists of two small, oval, pieces of the epidermis of the leaf cut 

 out and spun together at the edges and fastened to the twig by small 

 short silk bands. 



The mines of the two insects are also easily distinguished, that of 

 the Nepticula being a long narrow serpentine track only slightly widened 

 as the larva grows, and, if empty, with a semicircular slit at the end in the 

 upper epidermis, through which the larva has escaped ; while the 

 Coptodisca mine, which also begins as a narrow track, soon broadens 

 out into a several times wider, more or less circular blotch, and when 

 empty shows the oval hole in the leaf, where the larva has cut out the 

 upper and lower epidermis for its case. 



To distinguish between the shining dark Nepticula imago with its 

 tufted reddish-yellow head and the large eye-caps and that of the equally 

 shining light-coloured smooth-headed Coptodisca does not of course 

 present any difficulties. 



The following are some of the more important references only to : 



Nepticula pomivorella, Packard ; M icropteryx pomivorella, Packard, 

 17th Ann. Rep. Bd. Agr., pp. 237-8, 1870; Amer. Naturalist, Vol. IV., 

 p. 685, 187 1 ; Hayden" Bull. Geo. Survey, Vol. IV., p. 157, 1878 ; J. B. 

 Smith, List of Lep. No. 6020, 1891 ; Bull. No. 26 (new series), Dept. of 

 Agr., p. 94, 1900. 



