574 



WILLIAM T. M. FORBES 



Subfamily NYMPHULIN> 

 (Hydrocampinse) 



Similar to the Pyraustinae, except for the usual stalking of R, with R 3+4 (fig. 

 346). Maxillary palpi always wrell developed (figs. .348 to 351); labial palpi 

 normally upturned with well-marked segments, and a good-sized third segment. 



Caterpillars of all our known native species aquatic, forming some sort of a 

 case or shelter; frequently with tracheal gills, and spiracles reduced. Lateral 

 setse on ninth segment of abdomen obscure, and i close to iii; hooks arranged 

 in a complete ellipse, alternately of two lengths. 



Those caterpillars without gills show no single difference from the Pyraustinae. 



FIGS. 346-351. NYMPHULIN^; 



346, Nymphula icciusalis, venation; 347, Elophila fulicalis, venation; 348, A T j/m- 

 phula gyralis, side view of head; 349, Elophila fulicalis, side view of head; 350, 

 Geshna (?) primordialis, side view of head; 351, Diathrausta reconditalis, side 

 view of head 



The pupae are very thin-skinned, and often with spiracles of two sizes, only 

 the larger ones being functional. The cocoon is filled with air even in those 

 species that breathe water in the larva; but is often completely submerged. 

 So far as known to me the species are two-brooded, hibernating under water 

 as part-grown larvae. Some may feed a little through the winter. 



Key to the genera 

 ( Imago ) 



1. Hind wing with a vein lost (M 2 ). 



2. Palpi porrect (fig. 351) (black species) 52. Diathrausta. 



2. Palpi upturned (fig. 349) (light species) 51. Elophila, in part. 



1. Hind wing with all veins preserved. 



2. Palpi porrect, with scaling continuous on second and third joints; ter- 

 restrial 54. Eurrhypara. 



2. Palpi obliquely porrect, with well-set-off segments (fig. 350) ; tongue 

 extremely stout, much thicker than palpi; in wet places, but probably not 



aquatic 53. Geshna. 



2. Palpi upturned, with strongly curved second joint, and close-scaled third, 



well set off; aquatic. 



3. Maxillary palpi regularly tapering to apex (fig. 349); outer margin 

 of hind wing with a metallic and black border extending to Cu 2 . 



51. Elophila, in part. 



3. Maxillary palpi somewhat broad-scaled at tip (fig. 348); outer margin 

 of hind wing with, at most, a few small black dots opposite lower angle 

 of cell 50. Nymphula. 



