
AQUATIC INSECTS OF FRESHWATER 

generally distributed species of Haliplus are //. fasciatus and H. ruficollis, 
Fig. 230, and of Cnemidotus, C. punctatus. They are harmless to young 
fishes but have been observed to feed upon spawn. 
SmatLerR Warer-Beettes. A small water-beetle of the family Par- 
nid, Psephemus lecontii, Fig. 231, has a dark ees body clothed 
with fine silken hair to retain a film of air when 
it crawls below the water surface, adhering to 
plants and stones, as the legs are not so well 
developed forswimming. The larva is very flat, 
broadly oval or almost circular, 7, inch in length, 
and consists of 10 to 12 closely fitted segments. 
It lives principally upon vegetal substances 
but attacks the spawn of snails and fishes. 

Another small aquatic beetle belonging to 
the family of Heterocerus, H. pusi/lus, hasan FIG. 231. A Smaller Water-beetle, 
oblong or nearly oval form of dark-brown color a Raa ds 
with bands and spots of yellow. It is almost covered with hairs for the 
retention of air and burrows galleries into the mud at the margins of ponds 
and streams. ‘The mouth parts are developed for biting. The larve 
and nymphe of another member of this family, H. roseatus, are of a 
bright-red color. 
There are many other small Water-beetles not so frequently met 
with and mention of all of which would too greatly amplify this volume. 
They are usually harmless to fishes, and are scavengers rather than 
active enemies. 
Orver Lepipoprera. Of this order a number of families abound 
in the neighborhood of marshes and ponds and several species feed upon 
the leaves of aquatic plants. Of these the larve have in various de- 
grees adopted an aquatic existence. They are the China-Moths or Hydro- 
campa, the China-Marks or Cataclysta, and several other smaller genera. 
Cuina-Morus belong to the genus Hydrocampa, the species varying 
in length of body from 3¢ to 5% inch and in spread of wings from 34 to 
114 inch, while the larve or caterpillars are 1% to 1 inch long, of a white 
color tinged with yellow, with 
the body thickest at the mid- 
dle and narrowed at both the 
ends, having 16 feet, the last 
pair very short. The popular 
name of the moth is dueto the 

markings on the wings which 
FIG, 232. Water-moths. China-moth, Hydrocampa obliteralis 
and China-mark, Cataclysta fulicalis. Enlarged with extended wings, are white, mottled with Vidioyis 
272 
