The family Molannidae is the only group of Integripalpia which includes 

 species feeding on animal food. Under experimental conditions, the larvae of 

 Molanna angustata rejected vegetable food even when starved; they 

 consume large numbers of animals; when they feed on oligochaetes, their 

 daily food index is 61.1%, on Tendipedidae it is 41.8%, and on Daphnia 

 80.5%. Plankton organisms are more numerous than bottom organisms in 

 the stomach of larvae caught in nature; for example, in the stomach of 

 Molanna angu st at a, the frequency of D aphn i a m a gn a was 68.6%, 

 of D.pulex 37.5%, of Bo s mina sp. 43.6%, of Chydorus sphaericus 

 21.8%, of Copepoda 25%, -of Rotatoria (Anuraea aculeata, Brachionus 

 mulleri) 46.9%, but oligochaetes were found in only 12.5% of the dissected 

 stomachs and Tendipedidae in 40.5% (Kolenkina, 1951:47). The stomach of the 

 the larvae of Molanna angustata also contained planktonic and 

 planktonic-benthic forms Daphnia longispina, Bosmina longi- 

 ros.tris, Camptocercus r e c t i r o s t r i s, A 1 on a rectangula, 

 Graptoleberis testudinaria, Rhynchotalona rostrata, 

 Paracyclops f imb r iat u s, C ant ho c ampt u s sp. (Krokhin, 1929:73). 

 These data show that the larvae of Molanna are typical but not exclusive 

 plankton feeders; plankton organisms are the main food of these larvae, 

 and bottom organisms are secondary. 



It may be asked how a slow-moving, bottom -inhabiting insect catches 

 plankton animals. This is naturally possible only after the death of the 

 plankton animals; the larvae of Molanna which live on the bottom feed 

 on the falling "rain of corpses"; they collect this food on the bottom, but 

 they also swallow small, live animals which live temporarily or permanently 

 on the bottom, e. g., species of Alon a and Rhynchotalona, Para- 

 cyclops fimbriatus, Acanthocyclops viridis; species of 

 Canthocamptus; animals living in the bottom soil (Oligochaeta, 

 Tendipedidae) are less accessible to the larvae of Molanna. 



In the stomach of Molannodes tincta both animal and vegetable 

 food was found (Siltala, 1907:15). 

 62 The feeding of the large larvae of the family Limnophilidae was studied 



repeatedly; These species were correctly described as phytophagous. 

 The data collected refer to the feeding of a large number of species of 

 Limnophilidae, including such widely distributed species as Nemotaulius 

 punc t at ol ine at u s, G ly ph ot ae liu s pellucidus, Grammotau- 

 lius atomarius, Limnophilus rhombicus, L. nigriceps, 

 L. politus, L. flavicornis, L. stigma, L. marmoratus, L. vitta- 

 tus, L. centralis, L. sericeus, L. bipunctatus, L. extricatus, 

 L. indivisus, L. lunatus, Anabolia nervosa, A. s o r o r, Colpo- 

 taulius incisus, Halesus int e r punc t at u s, H. digitatus, 

 Chaetopteryx villosa, Platyphylax digitatus, Micropterna 

 lateralis, Potamophylax nigricornis, Apatania fimbriata. 

 Observations on the feeding of these species and analyses of the contents 

 of the intestine established that plants and algae predominate in their food; 

 some species (L. nigriceps, L. rhombicus, L. decipiens, 

 L. bipunctatus and Nemotauli u^ punctatolineatus) alse eat 

 moss; animal remains are rarely found in the stomach of the larvae 

 of the above species but in small numbers, and not in all species. 



Kolenkina (1951:46) studied in detail the stomach contents of 16 speci- 

 mens of Nemotaulius punctatolineatus, 19 specimens of Anabolia 



56 



