Philopotamidae, Stephens, 1829

Lee, Jonathan, 2024, Descriptions of the larvae and pupae of Sisko Ross with notes on western Dolophilodes Ulmer larvae (Trichoptera: Philopotamidae), Zootaxa 5428 (1), pp. 124-134 : 132

Key to Larvae of North American Philopotamidae Genera.

The following key is modified from that of Morse et al. (2019). Figures 19.360 –19.366 refer to those of Morse et al. (2019); figures 8.1A–8.1C, 8.1F, 8.2B– 8.2E, 8.3C– 8.3E refer to those of Wiggins (1996); figure 1B refers to that of Weaver et al. (1981). Figures 1–12 are original in this paper. The larvae of the purported eastern population of Sisko are currently unknown.

1 Prothoracic coxae each with long slender, subapicodorsal process bearing apical seta (figs 19.364, 8.1C); foretrochantins small and scarcely projecting (fig. 8.1A); anterior margin of frontoclypeus with prominent notch, typically asymmetrically right of midline (fig. 8.1B); head with setae number 18 at level of posterior point of ventral apotome (figs 19.365, 8.1F); widespread..................................................................................... Chimarra Stephens

- Prothoracic coxae without long subapicodorsal processes; foretrochantins small and not projecting (figs 8.3D, 8.3E) or elongate and finger-like (figs 19.363; 8.2C, 8.2D); anterior margin of frontoclypeus variable, prominently notched, slightly sinuous, or completely symmetrical; head with setae number 18 approximately halfway between posterior point of ventral apotome and occipital foramen (figs 19.366; 8.2E, 8.3C)................................................................. 2

2 Foretrochantins small, scarcely projecting (figs 8.3D, 8.3E); anterior margin of frontoclypeus symmetrical, most commonly slightly convex (figs 19.362; 8.3B) or slightly concave, but can have a central emargination or be distinctly crenulate; widespread........................................................................ Wormaldia McLachlan

- Foretrochantins projecting, finger-like (figs 19.363; 8.2C, 8.2D; Fig. 6 ); anterior margin of frontoclypeus variable........ 3

3 Anterior margin of frontoclypeus symmetrical or asymmetrically concave on right (figs 19.361; 8.2B; Figs 9–12 ); if small notch associated with asymmetry, then mandibles with crenulate lateral margins ( Fig. 9 ); widespread........ Dolophilodes Ulmer

- Anterior margin of frontoclypeus with distinct notch (fig. 19.360; Figs 1–4 ); mandibles without crenulate lateral margins... 4

4 Anterior margin of frontoclypeus with distinct notch on right (figs 19.360; 1B); larval length to 15 mm; Southeast U.S. (mountains)....................................................................... Fumonta major (Banks)

- Anterior margin of frontoclypeus with distinct notch central (most common) or with notch left or right of center ( Figs 1–5 ); larval length to 7 mm; Western U.S............................................................... Sisko Ross

Figures

FIGURES 1–4. Variation in Sisko larval head capsules and mandibles, dorsal. 1) Form 1: California, Humboldt County, perennial creek, head width 0.6 mm. 2) Form 2: Oregon, Curry County, perennial creek, head width 0.5 mm. 3) Form 3: California, Humboldt County, seasonal creek, head width 0.7 mm. 4) Form 4: California, Trinity County, seasonal creek, head width 0.7 mm.

FIGURES 5–8. Sisko larvae and pupae. 5) Form 4: Larval head, frontal, California, Trinity County, seasonal creek. 6) Form 1: Larval head and prothorax, left lateral, California, Humboldt County, perennial creek. 7) Form 1: Pupal head, ventral, California, Humboldt County, perennial creek, width 0.7 mm. 8) Form 1: Pupal abdomen, segments II–VII, dorsal, California, Humboldt County, perennial creek, length of segments II–VII 1.7 mm.

FIGURES 9–12. Dolophilodes spp. head and mandibles, dorsal. 9) Dolophilodes aequalis (Banks 1924), California, El Dorado County, head width 1.2 mm. 10) Dolophilodes dorca (Ross 1938), California, Humboldt County, head width 1.1 mm. 11) Dolophilodes novusamericana (Ling 1938), California, Humboldt County, head width 0.9 mm. 12) Dolophilodes pallidipes Banks 1936 (presumed larva), California, Siskiyou County, head width 0.9 mm.