LEPIDOPTERA OF NEW YORK AND NEIGHBORING STATES 341 



6. PLUTELLA Schranck 



Head somewhat rough, but less so than in Argyresthia; ocelli present, small; 

 maxillary palpi porrect, small in our species; labial palpi with a long triangular 

 tuft on second segment; third smooth-scaled and sharply pointed, upturned; 

 antennae with pecten; more roughly scaled than in Ypoiiomeuta; hind tibi<e 

 smooth; wings broad-lanceolate, not distinctly falcate; Mj and M 2 of hind wing 

 approximate or fused on basal third (figs. 20.), 201) (fused in our species), then 

 separating; the other veins separate. 



Larva (fig. 209) forming a slight web on Cruciferse. Prolegs slender, with a 

 single circle of hooks at the enlarged end; seta vii of metathorax single; abdomen 

 with setae iv and v remote. Pupa in a cocoon of regular, open meshes, which does 

 not at all conceal it. Pupa similar to that of Ypoiiomeuta, but with the thoracic 

 spiracle tubular, as well as the others, the cremastral setae hooked, and the tongue 

 more than three-fourths the length of the wings. 



1. P. maculipennis Curtis (The diamond-back moth.) Wings narrower and 

 more lanceolate than P. porrectella; with Mj and M 2 of hind wing fused two-thirds 

 way to the margin. Fore wing of male with upper two-thirds mouse gray, lower 

 third pale, the boundary usually marked by a darkening of the upper and a whiten- 

 ing of the lower ground color, with three sharply marked teeth. Female paler, 

 without contrasts, but with the markings, so far as traceable, like those of the 

 male. 13 mm. (cruciferarum Zeller; xylostella in part; male limbipennella, female 

 mqllipedella Clemens; female dubiosella Beutenmuller) . 



Caterpillar green with black head. On various Cruciferae; often injurious to 

 cabbage. 



% Generally distributed; probably introduced from Europe. New York: Ithaca, 

 Albany, West Farms. 



2. P. porrectella Linnaeus. Wings broader; M t and M 2 fused only one-third way 

 to margin; fore wing paler; luteous, \vith only traces of the diamond-back markings. 

 Outer margin and fringe contrastingly blackish (vigilaciella Clemens). 14-15 mm. 



Larva on the more slender Cruciferae, such as Hesperis. Similar to P. maculi- 

 pennis, but with brown head. 



Europe; New Jersey; also on Pacific Coast. Probably introduced in the East. 



7. CEROSTOMA Latreille 



(With Trachoma, Harpipteryx. Periclymenobius, Credemna. etc.) 

 Similar to Plutella. Wings in our species falcate; R and M! of hind wing, and 

 sometimes R 4 and R 5 of fore wing, stalked; Mj free and well separated from M 2 ; 

 palpi with triangular tuft decidedly larger, and third joint proportionately quite 

 small, but of the same character. Of the numerous subgenera which have been 

 formed, our falciferella belongs to Trachoma, with R 4 and R 5 separated, and 

 dentiferella and xylostella to Harpipteryx ( Periclymenobius ) , with R, and R 

 stalked. 



Larva similar to that of Plutella, with the hooks of the prolegs in a single row. 



1 . C. falciferella Walsingham. Wings very long and narrow, of almost even 

 width, with falcate tip and nearly erect outer margin. Powdery grayish brown 

 with two darker parallel oblique shades, (ordinalis Meyrick.) 



Larva to be expected on Rosaceae. Moth in August. 



Highlands of the Hudson, New Jersey; Ithaca, New York; Pacific States. 



2. C. dentiferella Walsingham. Wings with extended falcate apex. Fore wing 

 pinkish buff on costal two-thirds, pale yellow along inner margin; with a broken 

 darker shade along the boundary, black in California specimens. Hind wing pale. 

 (frustella Walsingham.) 



Known from California; Douglas Lake, Michigan; and Ontario (where the 

 pale form canariella has been taken in July). 



