nervosa and 122 specimens of the species Limnophilus (L.nigriceps, 

 L. decipiens, L. bipunctatus, L. rhombicus, L. politus, L. stig- 

 ma, L. mar m or at us); she found in all intestines without exception remains 

 of plants and algae (Oedogonium, Cladophora, diatoms, etc. ). 



Animal remains were found only in the stomach of one species — 

 L. rhombicus (frequency 17.8%). When the larvae of the above nine 

 species wereTed with mixed food, they accepted only vegetable food; when 

 fed with vegetable food, they readily fed on fallen leaves and C ladophora; 

 the food index for leaves was 98.6% in Nemotaulius punctatolinea- 

 tus, 67.3—87.0% in the other species; for algae, the food index of 

 L. b ipunct at u s was 94.0% and in the other species 78.8 — 88.1%. If there 

 was no vegetable food, starved larvae of N. punctatolineatus began to 

 feed on oligochaetes (daily food index 5.8%), rejecting Chironomidae and 

 Daphnia; the larvae of L.nigriceps reject Daphnia but eat 

 oligochaetes and Chironomidae (daily food index 6.0—7.4%); when L. d e c i - 

 pens, L. bipunctatus, L. rhombicus, L. politus, L. marmora- 

 tus are deprived of. plants, they eat small numbers of all three species of 

 animals offered, and their daily food index varied from 1.2 to 8.0%; only 

 two species (L. bipunctatus and L. p o 1 it u s) had a food index of 27.2% 

 and 17.4%, respectively, when fed with oligochaetes. Larvae of Limnophi- 

 lidae apparently feed on animals only when forced; this is rarely observed 

 in nature where vegetable food is abundant. This seems correct for the 

 above studied endemic limnophilic species which live in shallow water, 

 well warmed in summer and with a rich vegetation. However, the feeding 

 of rheophilic species of Limnophilidae in cold mountain streams is 

 apparently different; for example, in the Teberda River, at an altitude of 

 about 1,300— 1,400 m, when larvae of Rhyacophila and large, well-fed 

 larvae of Halesus 20— 22 mm long were caught in a dish near the bank 

 of the river (water temperature about 10°) on 23 July 1954; the Halesus 

 larvae attacked the Rhyacophila larvae immediately and devoured them 

 (E. A. Tetyueva). 



When fed with different types of vegetable food in the "courtyards" 

 Limnophilus rhombicus, L. nigriceps and L. decipiens 

 preferred tree leaves but also fed on Cladophora (the first two species) 

 63 and H y p n u m; the larvae of L. rhombicus ate the alga Hydrodiction 

 and sedge leaves; the larvae of L. nigriceps fed on E 1 o d e a; fallen tree 

 leaves were found in large quantities in. the food of L. politus and 

 L. b ipun ct at u s, but the former species preferred Cladophora and 

 Hypnum while the second preferred Cladophora and pine needles. 

 The readiness of the larvae to feed on decomposing tree leaves may be due 

 to the nutritive value of the leaves and to the bacterial and fungal flora on 

 them. O. L. Kachalova bred larvae of L. nigriceps in a dish with black 

 leaves; she observed that the larvae feed readily on hyphae of the mold 

 developing on the leaves in neglected aquaria; the larvae grew and 

 developed well on this food. 



When deprived of food, the larvae of species of Limnophilus eat each 

 other on the second day of starvation; they first eat the vegetable case and 

 then the larva itself. Limnophilidae (and Phryganeidae) can stand starvation 

 for a long time; a starved medium- sized larva of Limnophilus politus 

 died on the 18th day (water temperature about 19°); a larger larva of 

 L. rhombicus lived for 47 days without food. 



57 



