Procladius (Holotanypus) freemani Sublette

Saether, Ole A., 2010, Procladius Skuse from Lake Winnipeg, Manitoba, Canada, with keys to some females and immature stages of the genus (Diptera: Chironomidae), Zootaxa 2726, pp. 34-58 : 44

Procladius (Holotanypus) freemani Sublette

(Figs 8 A–C; 12 B, H; 13 B, I, L; 14 E)

Procladius freemani Sublette, 1964a: 122 .

Prothenthes choreus ? Malloch, 1915: 387.

Procladius (Procladius) freemani Sublette ; Roback 1971: 170, 1980: 36; Saether 1977: 48.

Material examined. CANADA: Manitoba, Lake Winnipeg, Victoria Beach, 10 males, 9.vii. & 25.vii. 1969; Pine Dock, 20 males, 2 females, 10.vii. 1969; 0.5 km off George Island, 5 males, 11.vii. 1969; 3 km off Grand Rapids, 61 males, 13.vii. 1969; 10 km off Long Point (Sturgeonskin Point), 1 male, 14.vii. 1969; 3 km off McCreary Island, 2 males, 15.vii. 1969; Gull Harbor, 8 males, 16.vii. 1969; Grand Rapids Government Wharf, 374 males, 28.vii. 1969; 5 km off Selkirk (Horse) Island, 4 males, 29.vii. 1969; Mukutawa River Buoy, 2 males, 3.x. 1969; McBeth Harbor, 1 male, 30.vii. 1969; Beaver Point, 45 males, 30.vi.–19.viii. 1969; 20 Mile Creek, 17 males, 26.viii. & 1.ix. 1969; Old Fishing Dock, 66males, 11. & 18.viii.1969; Calders Dock, 7 males, 5.–31.viii. 1969; Hecla Island, 44 males, 24. –25.viii. 1969; Beaver Creek, emergence trap, 2 males, 19.vii. 1969; off Ironwood Point, 1 male reared from larva, 25.vii.1969; South Basin, 260 larvae, 4.vi.–31.x. 1969; Narrows, 182 larvae, 4.vi.–31.x.1969; North Basin, 261 larvae, 2 pupae, 4.vi.–31.x. 1969.

The gonostylus of the Lake Winnipeg specimens (Fig. 8 C) appear to be most similar to the Saskatchewan and Wisconsin specimens illustrated by Roback (1971 figs. 280–281). Also the male scutum (Fig. 8 B) appears to be close to the Wisconsin population ( Roback 1971 fig.295). The tentorium, stipes and cibarial pump appear in Fig. 8A.

The female lacks setae on anepisternum II, has about 25 setae on segment X and about 9–14 sensilla chaetica proximally on each ta1 of p2 and p3.

Pupa (n = 3)

Cephalothorax. Thoracic horn ( Fig. 12 B) 380–442 µm long, 120–128 µm wide, plastron plate diameter 72– 132 µm, apical constriction of horn chamber 32–66 µm wide, length/width of thoracic horn 2.97–3.63, width of thoracic plastron plate /width of horn 0.59–1.10, width of plastron plate/width of constriction 1.94–2.25. Abdomen. Anal lobe ( Fig. 12 H) with 32–37 spines along outer margin, medium length spines in relatively sparse row posterolaterally.

Fourth instar larva (n = 10, except when otherwise stated)

Head capsule length 570–760, 680 µm (600) [ 660–780 µm in Moore & Moore (1978)].

Head. Antenna as in Fig. 13 B. Length of antennal segments (in µm): 152–134, 172; 19–22, 21; 6–8, 7; 2; 2. AR 4.69–6.30, 5.56 [4.00– 6.25 in Roback (1980), 5.4–6.3 in Moore & Moore (1978)]. Basal antennal segment 34– 38, 36 µm wide; 4.22–5.11, 4.79 times as long as wide; ring organ 0.71–0.78, 0.75 from base; blade 24–33, 26 µm; accessory blade 18–26, 23 µm long. Apical style of second segment 5–8, 7 µm long. Apex of labrum as in Fig. 13 I. Mandible 120–138, 132 µm long[ 140–150 µm in Moore & Moore (1978)], 151–200 µm in Roback (1980)]. Maxilla about as in P. culiciformis ( Fig. 14 B); palp ( Fig.14 E) 44–52, 48 µm long; 18–20, 19 µm wide; 2.32–2.78, 2.50 times as long as wide; 2-segmented sensilla basiconica (SBP) shorter than bisensillum (Bs), its basal segment shorter than its apical segment. Length of basal antennal segment/length of palp 3.04–4.05, 3.58. Hypopharyngeal pecten with 11–13, 11.6 (16) teeth.

Abdomen. Claws of posterior parapods about as in P. culiciformis ( Fig.14 K).

Distribution and ecology. The species including its varieties is known from all over U. S. A. and Canada ( Oliver et al. 1990: 15; Spies 1999; Epler 2003, 2010; Caldwell 2009). In addition to the records by Roback (1971: 171) specimens have been found from Harding Lake, Alaska, Marion Lake, British Columbia and South Indian Lake, Man. The species appears to be primarily a lake species perhaps most common in moderately eutrophic to oligotrophic lakes. The distribution in Lake Winnipeg is shown in Fig. 1 , the emergence pattern in Fig. 9 .

Figures

FIGURE 1. Larval distribution of the five most common species of Procladius Skuse in the benthos of Lake Winnipeg.

FIGURE 9. Procladius (Holotanypus) freemani Sublette. Numbers of adults caught in light traps and emergence traps in 1969 and 1971, and numbers of immatures in benthic samples from June to November 1969 and in March 1970. (LT = light traps, ET = emergence traps, short vertical lines = 1 – 25 specimens, medium long lines = 26 – 50 specimens, longest vertical lines = 201 – 400 specimens, 1 = first instar larvae, 2 = second instar larvae, 3 = third instar larvae, 4 = fourth instar larvae, P = pupae.)

FIGURE 12. Procladius spp., pupae; thoracic horn (A – F), anal lobe (G – L), spinule pattern of tergite IV (M, N). A, G – Procladius (P.) bellus; B, H— Procladius (H.) freemani Sublette; C, I— Procladius (H.) culiciformis (L.); D, J— Procladius (H.) rugulosus sp. n.; E, K, M— Procladius (H.) denticulatus Sublette, F, L, N— Procladius (H.) sublettei Roback.

FIGURE 13. Procladius spp., larvae, antennal apex (A – E), antenna (F – G), labrum (H – J), and ligula, paraligula and hypopharyngeal pecten. A, F, H, K— Procladius (P.) bellus (Loew); B, I, L— Procladius (H.) freemani Sublette; C— Procladius (H.) culiciformis (L.); D— Procladius (H.) denticulatus Sublette; E, G, J, M— Procladius (H.) sublettei Roback.

FIGURE 14. Procladius spp., larvae; maxillae ventral view (A – B), dorsal view (C); maxillary palp (D – H), claws of posterior parapods (I – L). A, D, I, J— Procladius (P.) bellus (Loew); B, F, K— Procladius (H.) culiciformis; C, G, L— Procladius (H.) denticulatus Sublette; E— Procladius (H.) freemani Sublette; H— Procladius (H.) sublettei Roback.