Lepidoptera of New York and Neighboring States 577 



Caterpillar in an oblong case on Potamogeton, sedge, Lemna, Menyanthes, and 

 other aquatic plants. Cocoon sometimes anchored under water. Moth in August. 



Common everywhei e, flying over the water and along the shore of ponds. New 

 York: Saranac Lake, Saranac Inn, Lancaster, Otto, Potter Swamp (Yates 

 County), Ithaca, Big Indian Valley, Nassau, Rhinebeck, New Windsor. 



3. N. obliterans Walker. Fore wing not falcate. Dull black, obscurely marked 

 with ochre and a little white, with obscure light blue iridescence ; hind wing 

 similar, or almost completely suffused with black; discal iunule white on both 

 wings. Female lighter, browner, with more diffuse markings, and much larger; 

 discal lunule often very weak. 10-16 mm. 



Larva on water lilies ( Nymphseaceae ) ; sometimes a minor pest in greenhouses. 



Quebec, and south; common southward. New York: Hemlock Lake, Rhinebeck. 

 (Usually a greenhouse pest northward, but the Hemlock Lake specimens, at least, 

 were taken outdoors. ) 



4. N. gyralis Hulst. Male fuscous or light brown; base a little darker, bounded 

 by a waved white line; costal triangle a white outline, filled with blackish and 

 edged with white, the outline often broken; reniform lunule a curved black line, 

 edged with white and often connecting with a short black and white subter- 

 minal streak on costa; subterminal line whi1;e, irregular, edged with brown. Hind 

 wing white, with vague fuscous ante- and postmedial lines, often fusing on dorsal 

 half of wing; postmedial line followed with white, and strongly irregular; discal 

 spot vague, grayish; subterminal line as in fore wing, in a brownish or yellowish 

 shade. Female with markings the same as far as traceable; ground lighter 

 brown, or dirty yellow, the markings often suffused; hind wing white with slight 

 gray markings. 20 mm. 



General, but relatively rare; larva on water lily. 

 New York: Big Tupper Lake, Saranac Lake, Lewiston. 



In southern specimens portions of the ground are light ochre yellow; northern 

 ones are usually wholly fuscous brown and white. 



II. Larva with tracheal gills, two subdorsal, two subventral, and a pedal 

 pair on most segments; the subventrals with an equal number of filaments ; 

 second and thi/rd abdominal spiracles equal, . all very small; case filled with 

 water; pupa with the three open spiracles equal in size, with a median longv- 

 tudmal carina on ninth segment of abdomen. Imago with venation as in the 

 last group; palpi merely rough-scaled; hind wing immaculate, or with a faint 

 postmedial line only (Nymphseella Grote) . 



5. N. maculalis Clemens. Normal male. Fore wing not falcate; maxillary palpi 

 rough and larger than third segment of labials; fore wing white, marked with 

 dark gray, leaving the white mostly as ante- and postmedial patches in the fold;- 

 a vaguer one in the outer part of the cell, and two confluent ones near the outer 

 margin. All the patches connected in light specimens; in dark ones only the 

 two on the fold contrasting. Hind wing white, sometimes with a gray post- 

 medial line on dorsal part. Normal female. Fore wing immaculate mouse gray, 

 and hind wing white; much larger. 18-25 mm. (seminivella and dispar Walker.) 



Caterpillar on the water lilies, and rarely on Brasenia; in the last stage, with 

 five filaments on the posterior subdorsal and all subventral gills of most segments, 

 the anterior subdorsals usually with four. First stage without gills, and the 

 intermediate stages with smaller numbers of filaments. Caterpillar immaculate, 

 transparent till just before pupation, then turning yellow; pupa generally under 

 a piece of leaf on a floating lily pad. 



Common and generally distributed, flying over water. New York : Saranac Lake, 

 Big Tupper Lake, Lewis County, Spencer Lake. 



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