AQUATIC INSECTS OF FRESHWATER 



generally distributed species of Haliplus are H.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. 



Smaller Water-Beetles. A small water-beetle of the family Par- 

 nidffi, Psephemus kcontii, Fig. 231, has a dark five-jointed body clothed 

 with fine silken hair to retain a film of air when y' ^ 



it crawls below the water surface, adhering to 

 plants and stones, as the legs are not so well 

 developed for swimming. The larva is very flat, 



broadly oval or almost circular, ^ inch in length, ^nii/7in"'iiraM«iBi v^ 'Hk 



and consists of 10 to 12 closely fitted segments. :^^ ||||' {||}|||| \ 111 

 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. pusillus, has an fig. 231. a Smaller Water-beetie, 



^ , , I ^ r 1 1 t 1 Psephemus lecontii. Greatly enlarged. 



oblong or nearly oval rorm or dark-brown color 



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 larvae 

 and nymphas of another member of this family, H. rosaatus, 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. 



Order Lepidoptera. 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 larvas have in various de- 

 greesadopted an aquatic existence. They are the China-Moths or Hydro- 

 campa, the China-Marks or Cataclysta, and several other smaller genera. 

 China-Moths belong to the genus Hydrocampa, the species varying 

 in length of body from ^ to ^ inch and In spread of wings from l/^ to 

 ij^ inch, while the larvae or caterpillars are i/^ to i 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 due to the 

 markings on the wings which 



FIG. 132. Water-moths. China-moth, Hydrocampa ohliteralis . . 



and China-mark, Cataclysta fulicalis. Enlarged with extended wings, are whlte, mOttled with Vary- 



272 



