Liopterus haemorrhoidalis (Fabricius, 1787)

Source of material. The four instar III larvae were collected in association with adults at the following locality: Belarus, Vicebsk Region, area near upy Village, wetland of evinka River, Carex, moss. 12.VIII.1998;H.Shaverdo leg.

Diagnosis (instar III). The third instar of Liopterus haemorrhoidalis can easily be distinguished from that of the other species studied in this paper by the following combination of characters: HL = 1.40 mm; L3> 2.90 mm; U> 0.50 mm; head capsule subquadrate, strongly constricted at level of occipital region (Fig. 58), scale-like sculpticels lacking over frontoclypeus and parietale; anterior margin of frontoclypeus broadly convex, extending mesally at level of adnasalia (Fig. 58); adnasalia margined with short bluntly rounded teeth (Fig. 65); MP2/MP1 <1.30; GA/MP1 <1.50; 1.30 <LP2/LP1 <1.90; inner margin of stipes with a dorsal linear row of spinulae (Fig. 60); profemur with less than 3 PV and more than 5 AV secondary setae; metafemur with more than 4 AV secondary setae (Fig. 61); urogomphus composed of one urogomphomere; U/HW = 0.40; U/LAS> 0.50; Palaearctic.

Description, instar III (Figs 58–62, 65)

Body: Measurements and ratios aimed to characterize body shape are shown in Table 6.

Head (Figs 58, 60, 65): Head capsule subquadrate, strongly constricted at level of occiput; anterior margin of frontoclypeus broadly convex, extending mesally at about level of adnasalia; scale-like sculpticels lacking over frontoclypeus and parietale; adnasalia margined with mostly short bluntly rounded teeth (Fig. 65); HL = 1.36–1.39 mm; A/MP = 1.16–1.27; MP/LP = 1.67–1.74; MP2/MP1 = 1.15–1.28; GA/MP1 = 1.27–1.49; LP2/LP1 = 1.54–1.71; MNL/MNW = 2.63–2.71.

Thorax (Figs 61–62): L3 = 2.86–3.06 mm.

Abdomen (Fig. 59): LAS = 1.09–1.17 mm; LAS subconical, constricted posteriorly at point of insertion of urogomphi. Urogomphus, U = 0.60–0.63 mm, composed of one urogomphomere; U/HW = 0.38–0.40; U/LAS = 0.54–0.57.

Chaetotaxy: Parietale with 7–10 temporal spines; position and number of secondary setae on legs are shown in Figs 61–62 and Table 7.