The Integripalpia developed progressively under conditions of abundant 

 food and high adaptive possibilities to extend their ecological range; they 

 are represented in the recent fauna by 19 families. We describe the 

 larvae of 1 1 families of the 12 families occurring in the USSR in the next 

 part of this work. 



The phylogenetic relationships between the family groups of Integripalpia 

 are much more complicated in the larvae than in the Annulipalpia; the 

 family groups proposed by various authors (based on the characters of the 

 early stages of development) are not convincing. 



To the family groups with relatively primitive larvae, which have simple, 

 unspecialized sclerites and a little varying form of the legs, belong the 

 Phryganeidae, Phryganopsychidae, part of the Limnophilidae (Drusinae) and 

 the Lepidostomatidae; to the group of highly specialized families with a 

 rich secondary chaetotaxy of the legs, which is sometimes completely 

 different on different legs both in form and function belong the Odontoceridae, 

 Calamoceratidae, Molannidae, Leptoceridae, Beraeidae and Sericostomatidae; 

 Goeridae and Brachycentridae are intermediate between the 2 aforementioned 

 groups. 



The phylogenetic scheme of the Annulipalpia in Figure 168 is based on the 

 morphology, biological characters and phylogenetic relationships of the 

 families in the larval and pupal stage and is therefore an attempt to show 

 the lines of evolution in the early stages of development. 



We shall now attempt to combine this phylogenetic scheme with at least 

 some of the characters of the adult insect; we select for this the structures 

 used also by earlier authors, i. e., the form of the last segment of the 

 maxillary palps and the presence or absence of ocelli. 



According to the presence of an undivided, slightly elongate segment of the 

 maxillary palps, the lower Annulipalpia (Rhyacophilidae, Glossosomatidae and 

 Hydroptilidae) are related to the Integripalpia; they differ in this character 

 from all Neochaetoidea and the higher Palaeochaetoidea (the "true campodeid 

 forms" separated as a group by Klapalek). The possession of an undivided 

 maxillary last palp segment is a character of some Annulipalpia which 

 suggests the ancient genetic relationship between the 2 suborders. This is 

 even more clearly marked in the larvae in a number of other characters, 

 including such important characters as the case -bearing habit and the 

 presence of a dorsal sclerite on abdominal segment 9. 



The presence of ocelli in the Annulipalpia is characteristic for the 

 families of the part of the phylogenetic scheme which contains the most 

 primitive forms, i. e., all Palaeochaetoidea, except the highest family of this 

 group, the Psychomyiidae. In the Integripalpia, ocelli are characteristic 

 only for families with relatively primitive larvae which are placed 

 immediately near the lower Annulipalpia, i. e., the Phryganopsychidae, 

 Phryganeidae and Limnophilidae; all the other families of the order, except 

 the Plectrotarsidae, are without ocelli. 

 174 We may thus conclude that both the above characters of the adult 



Trichoptera are directly correlated with the degree of primitiveness or 

 specialization of the same families in the larvae. 



163 



