In memoriam 



Andrei Vasil'evich Martynov 



PREFACE 



Trichoptera develop as aquatic animals living on the bottom. They 

 form a substantial part of the food resources of benthos-feeding fishes in 

 many large water bodies, including important species of Salmonidae and 

 Acipenseridae. 



If we wish to preserve and improve water bodies inhabited by 

 commercially valuable fish, many aspects of their life conditions have to 

 be studied. This calls for a study of the systematic composition and biology 

 of the food items, including the larvae and pupae of caddis flies. This is 

 also necessary for fish farms, nursery ponds and fattening ponds, as it 

 makes for an almost natural food supply. 



Generally useful, Trichoptera can be harmful. If they occur in multitudes 

 in large rivers in the plains, the caddis flies sometimes "flood" the 

 surroundings as they take wing and may cause damage to the local population. 



When hydropower stations are built, favorable biotopes for litho- 

 rheophilous animals such as caddis fly larvae are created on the compact 

 concrete walls of the discharge channels; when the larvae pupate, they cover 

 the walls of the channels with their cases, which consist of mineral particles; 

 the cases form incrustations on the walls which grow thicker from year to 

 year, reducing the channel profiles and thus impairing the efficiency of the 

 power plants. It is necessary for control purposes to know to which species 

 the harmful insects belong and to know their biology. 



The present monograph gives a description of the morphology of the 

 larvae and pupae of the Trichoptera of the USSR and of their biology and life 

 conditions. The description is based on the systematics of the group and is 

 accompanied with keys for identification. 



The laboratory workers of the section on Neuroptera, E. A. Tetyueva and 

 M. N. Kandybina, greatly assisted the author in the preparation of the present 

 volume. Tetyueva proofread the long typescript and made a card index of 

 the literature; she was also responsible for correspondence with libraries. 

 The greater part of the bibliography was prepared by her. Kandybina 

 prepared many of the drawings as well as the plates for printing the 

 drawings. I hereby convey my sincere gratitude to these two colleagues. 



The painters of the Zoological Institute of the Academy of Sciences 

 of the USSR (headed by T. F. Belotsvetova) made the illustrations 

 to the present volume. I extend my thanks to all these, especially to 

 N. L. Orshanskaya, who drew most of the figures from nature. The 

 original drawings are not marked in the legends; the names of authors of 

 drawings taken from other works are given in parentheses. 



I am very grateful to the editor, Prof. A. Strelkov, who gave his constant 

 attention to the present volume and supplied extremely valuable comments. 



S. G. Lepneva 



