The anterior margin of the frontoclypeus bears 3 setae at each side and 

 3 setae at the frontal suture; the anterior weakly sclerotized part of the 

 frontoclypeus projects above the margin of the epicranium and is separated 

 from the other part of the frontoclypeus by a deep groove; this part is 

 usually considered to correspond to the anteclypeus of the larva (Nielsen, 

 1942:314). 



The labrum of the pupa is contiguous with the anteclypeus (Figure 132); it 

 is narrower but longer than in the larva, and its dorsal surface is weakly 



87 sclerotized; its surface bears 6 setae on each side, sometimes only 

 3—5 setae; except seta 1 at the anterior margin, the setae are thick, 

 projecting anteriorly and sometimes long and hooked; at the end the setae 

 of the labrum are used to clean the anterior openings of the pupal case. 



With rare exceptions,* the mandibles (Figure 133) are well developed and 

 sclerotized; they consist of a broad basal part and narrow distal part; they 



88 are filiform at the apex in Psychomyiidae and Odontoceridae; the blade of 

 the mandible is finely serrated, often with several large or small teeth; the 

 outer side of the basal part of the mandibles bears 2 primary setae which 

 are accompanied by numerous secondary setae in some species. The 

 mandibles have two functions: they clean the anterior opening of the pupal 

 shelter in some species and break the wall of the shelter when the pupa 

 emerges. 



Maxillae and labium are not sclerotized and nonfunctional in the pupa; 

 the maxillary and labial palps of the pupa resemble those of the imago in 

 form and number of segments. 



Thorax. The prothorax of the pupa is much smaller than the meso- 

 thorax and metathorax, which contain the developing musculature of the wings. 



89 The wings lie in transparent wing sheaths at the sides of the pupa and partly 

 on its ventral side, where the wing sheaths of both sides come in contact or 

 slightly overlap. 



The hind and midlegs are long; the forelegs are much shorter; the 

 spurs on the tibiae form sheaths in which the spurs of the imago develop; the 

 spurs of the pupa are thicker and relatively shorter than those of the imago; 

 The tarsus has 5 segments; the pretarsus of most forms bears 2 short 

 pointed appendages: the claws of the pupa (Figures 134 and 135); the mid- 

 legs are rarely natatorial; their tarsal segments are long and broad, 

 bearing swimming combs dorsally and ventrally which consist of a row of 

 large, dense setae; the swimming setae are less numerous in some forms 

 on the hind legs, sometimes also on the forelegs. Species pupating near 

 the waterline or on land among moss or detritus do not have swimming 

 setae. 



Abdomen. The abdomen of the pupa resembles that of the imago, but 

 it is longer and thicker; its 9 segments are distinct; the 10th segment is 

 small and fused with the 9th. The pupa retains the larval lateral line and 

 the gills which are present, with rare exceptions, in the pupae of all Integri- 

 palpia; gills are also present in the pupae of some Annulipalpia (Poly- 

 centropodidae and Hydropsychidae). The pupal gills have usually the same 

 structure as the larval gills; in some groups of Annulipalpia gills are 



" In the family Phryganeidae, e.g., in the pupae of Ho lost om is, Oligostomis and Hagenella, the 

 mandibles are reduced as in the imagines and are short, nonfunctional membranous lobes; these species 

 pupate in tubular shelters, the anterior end of which is not covered with a woven membrane but is covered 

 with parts of plants; these pupae emerge easily through this opening without the help of the mandibles 

 (Wiggins, 1960:449— 452). 



