AQUATIC INSECTS IN NEW YORK STATE 207 



Professor Forbes in bis studies of Illinois fisbes (tbe brook 

 trout was not one of tbe fisbes be studied), bas clearly pointed 

 out tbe importance of tbese small larvae as fisb food: "Among 

 aquatic insects, minute slender dipterous larvae, belonging 

 mostly to Cbironomus, Coretbra and allied genera, are of re- 

 markable importance, making, in fact, nearly one tentb of tbe 

 food of all tbe fisbes studied."^ In bis report- on tbe aquatic 

 invertebrate fauna of tbe Yellowstone national park, almost 

 «very page testifies to tbe abundance, general distribution and 

 ecological importance of Cbironomus. On page 228 are given 

 «ome observations indicating tbat it is of as great importance 

 to young trout as to adults: 



Tbe pond was swarming witb mountain trout ( S a 1 m o 

 mykiss), a few of wbicb I dissected for a determination of 

 tbeir food. One of tbese an incb and a balf in lengtb bad eaten 

 Cbironomus larvae and images cbiefly, tbe remainder of its 

 latest meal consisting of otber insect larvae, not in condition 

 to identify, and tbe entomostracban P o 1 y p b e m u s p e d i - 

 cuius. A second, an incb and a quarter long, bad also fed 

 •on Cbironomus in its various stages of larva, pupa and imago, 

 but bad made about a tbird of its meal of Eutomostracba. 

 Another, still smaller (.92 of an incb long) taken from tbe open 

 lake among tbe small weeds growing on a flat, muddy rock, bad 

 :fllled itself witb Cbironomus pupae only, as bad still anotber 

 of tbe same size, A tbird specimen from tbis situation bad 

 eaten more larvae of Simulium tban of Cbironomus, and a 

 fourtb bad also eaten Simulium larva and anotber dipterous 

 larva unknown to me. I may add bere tbat otber young trout, 

 in a small swift rivulet near tbe Lake botel, were feeding con- 

 tinuously, Aug. 9, on floating winged insects, mostly, if not all, 

 Cbironomus and smaller gnatlike forms. 



Witb tbese certain indications of tbe economic importance of 

 tbe genus at band, it is indeed time we were able to recognize 

 its species. Mr Jobannsen's work in part 3 is a beginning in 

 tbat direction. All tbe above mentioned references, as well as 

 most otbers to immature stages wberever publisbed, are to tbe 

 genus only; and Cbironomus is a great genus, and includes 

 forms witb considerable diversity of structure, babitat and 



nil. state Lab. Nat. Hist. Bui. 2. p.4S3. 

 = U. S. Fish Com. Bui. 11, p.207-56. 



