families Xiphocentronidae and Psychomyiidae with a labium without palps 

 167 and prolonged in form of a ligula which contained the spinning organ; this 

 organ facilitates the construction and repair of the long tunnel- shaped 

 tube of the larva. 



Evolution along line 2 (line of the higher Paleochaetoidea) took place 

 under conditions of a concealed but very mobile mode of life inside tubes; 

 connected with collection of microscopic food from the walls of the tube; 

 the chaetotaxy (except that of the pronotum) remained mainly primary; 

 the membranization of the dorsum extended to the last 2 thoracic segments 

 and all abdominal segments, including segment 9. 



The group includes 2 pairs of phylogenetically related families; on 

 branch 2 ", these are the relatively large and primitive family Philopotamidae 

 and the small family Stenopsychidae with 47 species in the world fauna 

 (the Stenopsychidae were separated from the Philopotamidae); branch 2' 

 contains the relatively large family Psychomyiidae and the small family 

 Xiphocentronidae, which consists of only 4 species, which survived in tropical 

 Central America. 



Evolution along phylogenetic line 1 of stem I took place during the change 

 from phytophagy to a predatory life; this change was also expressed in the 

 transformation of the primitive tubular shelters into complex capturing 

 structures of various types (see p. 77). The development of a predatory 

 life required a number of morphological and physiological adaptations, 

 particularly the development of mobility and strength of the predator, and an 

 increase of its capacity for orientation. This was attained by the 

 development of a rich and highly differentiated secondary chaetotaxy. The 

 development of a group of predators in the Annulipalpia was, therefore, 

 closely connected with the development of the secondary chaetotaxy, or, in 

 other words, with the development of the superfamily Neochaetoidea. 



The change to predatory life could take place inside the tunnel- shaped 

 tubes, as in the recent Ecnomidae; this family consists of predators which 

 continue to live in the same tunnel- shaped tubes which are characteristic 

 of microphages. The structures of some genera of recent Polycentropodidae 

 (Plectrocnemia, Polycentropus, Holocentropus) retain even at 

 present a rather large tube part in which the larva waits for its prey and 

 maintains the good condition of the net; the tubular part of the structure 

 of Neureclipsis (which is situated at the apex of the funnel) is not longer 

 than the larva (Figure 123). The dwelling chamber of the larvae of 

 Arctopsychidae and Hydropsychidae is broad and short; the tube is trans- 

 formed into a saclike shelter; the capturing structures of these 2 families 

 do not form a funnel (a modified tube) but is a flat and skilfully woven screen 

 resembling a plankton net. The development of gills of the larvae of 

 Arctopsychidae and Hydropsychidae is also connected with their life in a 

 narrow space. 



The morphological specialization of the predators is expressed in the 

 adaptations for capturing and retaining food; the toothed mandibles of all 

 4 families of predators are a strong organ; the legs are used to catch and 

 hold the prey; some setae of the primary chaetotaxy and of the rich 

 secondary chaetotaxy of the legs are transformed into short, massive, 

 spear-shaped or spinelike organs which kill the prey. The rich secondary 

 chaetotaxy of the higher Neochaetoidea (Arctopsychidae and Hydropsychidae) 

 is mainly concentrated on the legs; in the Hydropsychidae (unlike all other 



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