Pupa. Length 10— 14mm. Antennae of male pupae coiled about 4 times 

 around body; antennae of female pupae shorter; first segment large, with 

 several short setae. Labrum (Figure 805, A) with a distinct, pointed process; 

 anterior part with numerous, short, secondary setae and all primary setae; 

 anteclypeus with 2 long and a short (posterior) setae. Mandibles 

 (Figure 805, B) long, curved, narrow distally; blade with 4—5 large teeth at 

 the curvature, serrated distally; lateral setae short, strong, apical dorsal 

 seta larger than ventrobasal seta. Wing sheaths narrow, reaching 

 abdominal segments 6—7. Fore and mid tibiae and tarsi natatorial, with 

 dense, large, thin setae. 



First abdominal segment with disk with spines and lateral processes 

 dorsally at the posterior angles (Figure 805, C). Holding apparatus on 

 segments 3 — 7, plates with the following number of denticles: segment III: 

 2— 3, segment IV: 2—4; segment V: 2—3 + 6—9; segment VI: 2—4; segment VII: 

 3—4. Lateral line on segments 3— 8, with small, grayish setae. Gills single 

 as in larva, long, presegmental on segments 2—8 dorsally and ventrally, 

 also lateral postsegmental gills on segment 2. Sclerite of segment 9 

 laterally with small lobe-shaped processes with 9—12 strong, dark brown 

 setae, 2 of them longer and thicker than the others. Rudimentary female 

 genitalia on segment 9 in form of a tubercle divided into 2 parts by a 

 median groove; male genitalia longer; penis sheath short, wide. Anal rods 

 thin, long, slightly curved (Figure 805, D) with small spinules from the base; 

 setae small, light; the first and second seta near the base of apical part, 

 the other 2 setae subapically. 

 505 Pupal case 11— 14mm long, attached at both ends by ventral disks; 



anterior membrane with wide round hole; posterior membrane with oblong 

 hole; membranes sometimes surrounded by small plant particles. 



Mode of life and habitats. Lakes and ponds, mostly on solid and 

 slightly silted bottom, rarely among vegetation or in the sublittoral; river 

 mouths; reservoirs. 



Distribution. The European USSR, the Caucasus, Western and 

 Eastern Sibiera, Middle Asia. In addition, Europe, Mongolia. 



2. Oecetis intima McLachlan, larva nova 



FHill- grown larva. Length 5 — 6mm. Resembling Oe. ochracea but 

 smaller, pale; sclerites yellowish white, without pattern or with sparse, 

 indistinct, pinkish or brownish spots. Head wide, slightly longer than wide; 

 dots on yellowish white background not always distinct; eyes small; 

 sensilla of antenna small, transparent, with small, light seta. Frontoclypeus 

 506 with wide, brownish, anterior margin; anterior part without dots or with 2 

 pairs of narrow, indistinct dots, dots of anterior pair more widely separated; 

 posterior angle with 2 large dots situated behind 2 transverse or several 

 small dots. Dorsal stripes absent, replaced in some specimens by a 

 longitudinal row of 4 small dots parallel to the frontal sutures; 2 large dots 

 close to suture near fork; 2 large, longitudinal dots and a pale, indistinct 

 dot lateral to coronal suture; ventral side light; gula wide, smoke brown. 

 Median and intermediate anterior-margin setae long; lateral anteiior- 

 margin seta small, indistinct; anterior frontal seta small, thin, situated 

 lateral to intermediate frontal seta; the latter long, situated before tentorial 



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