Copelatus glyphicus (Say, 1823)

Source of material. The five instar III larvae studied were associated with adults collected at the following locality: Canada. Québec, Trois-Rivières. Ephemeral pond in red maple forest at Chemin des Oblats, 06.VIII.1986, 08.VIII.1986, 12.VIII.1986; Y. Alarie leg. The identification is firm as C. glyphicus is the only Copelatus species known from that region.

Diagnosis (instar III). The third instar of Copelatus glyphicus can easily be distinguished from that of the other species studied in this paper by the following combination of characters: HL = 0.80–0.90 mm; L3 <2.00 mm; U <0.40 mm; head capsule rounded, strongly constricted at level of occipital region (Fig. 19), scale-like sculpticels present over frontoclypeus and parietale; anterior margin of frontoclypeus broadly convex, extending mesally beyond level of adnasalia (Fig. 19); adnasalia margined with short bluntly rounded and truncated teeth (Fig. 63); MP2/MP1> 1.50; GA/MP1> 1.50; 1.30 <LP2/LP1 <1.90; inner margin of stipes lacking a dorsal linear row of spinulae; profemur with less than 3 PV and 4 AV secondary setae; metafemur with less than 3 AV secondary setae; urogomphus composed of one urogomphomere; U/HW <0.40; U/LAS <0.50; Nearctic.

Description, instar III (Figs 19–20, 63)

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

Head (Figs 19, 63): Head capsule rounded, strongly constricted at level of occiput; anterior margin of frontoclypeus broadly convex, extending beyond level of adnasalia; scale-like sculpticels well-developed both on frontoclypeus and parietale; adnasalia margined with short bluntly rounded and truncated teeth (Fig. 63); HL = 0.81–0.94 mm; A/MP = 1.34–1.38; MP/LP = 2.12–2.17; MP2/MP1 = 1.50–1.73; GA/MP1 = 1.79–1.88; LP2/LP1 = 1.40–1.56; MNL/MNW = 2.85–3.04.

Thorax: L3 = 1.60–1.74 mm.

Abdomen (Fig. 20): LAS = 0.65–0.74 mm; LAS subcylindrical, not constricted posteriorly at point of insertion of urogomphi. Urogomphus: U = 0.28–0.32 mm, composed of one urogomphomere; U/HW = 0.31–0.33; U/LAS = 0.42–0.44.

Chaetotaxy: Parietale with 6–9 temporal spines; position and number of secondary setae on legs are shown in Table 7.