The building of the capturing net takes about 3 days (with interruptions). 

 As mentioned above, the larva builds in the evening or at the end of the night 

 and early in the morning; it ceases its activity during the day; one of the 

 mature larvae in the experimental pool of C. Brickenstein built its net 

 82 according to the following schedule (current 0.05 m/ sec): 7 August 1952 

 from 20.20 to 2.00; 8 August from 2.05 to 4.20 and from 22.00 to 23.40; 

 9 August from 5.00 to 6.00 and from 21.08 to 23.12; 10 August from 2.20 

 to 6.09; on the last date, the net was 29 cm long and the funnel 13 cm wide. 

 The whole construction thus took about 12 hours. 



(84) 



FIGURES 124-128. Construction of the capturing net of Hydropsyche angustipennis 

 (after Sattler): 



124 - model of dwelling chamber, entrance hall and net (A), connected sand particles of 

 dwelling chamber (B); 125 - diagram of the weaving planofnet; 126 - part of capturing net; 

 127 - larva weaving its net; 128 - pectinate hair of anterior tuft of the labrum of the larva. 



76 



