Procladius (Holotanypus) culiciformis

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 : 38-41

Procladius (Holotanypus) culiciformis (L.)

( Figs 4 ; 5; 12 C,I;13C; 14 B, F, K)

Tipula culiciformis Linnaeus, 1767: 978 .

Tanypus crassinervis Zetterstedt, 1838: 817 .

Prothenthes claripennis Malloch 1915: 387 .

Procladius choreus Edwards (in part), 1929: 301.

Procladius (Procladius) culiciformis (L.); Roback 1971: 175, 1980: 38; Saether 1977: 48.

Material examined. CANADA: Manitoba, Lake Winnipeg, 2 km off Selkirk (Horse) Island, 2 males, 4.vi. 1969; 4 km off Grand Rapids, 1 male, 8.vi. 1969; 0.5 km off George Island, 21 males, 11–12.vi. 1969; 3 km off Grand Rapids, 1 male, 13.vi. 1969; 10 km off (Sturgeonskin point) Long Point, 1 male, 15.vi. 1969; 3 km off McCreary Island, 20 males, 15.vi. 1969; Gimli Government Wharf, 41 males, 24.vi. 1969; 3 km off George Island, 6 males, 27.vi.1969; Grand Rapids Government Wharf, 14 males, 28.vi. 1969; 5 km off Selkirk (Horse) Island, 2 males, 29.vi. 1969; McBeth Harbor, 4 males, 30.vi. 1969; Mukutawa River Buoy, 1 male, 3.ix. 1969; Beaver Point, 7 males, 9.vi. 1971; 20 Mile Creek, 5 males, 26.viii. 1971; Old Fishing Dock, 20 males, 5. & 27.viii. 1971; reared from pupa: north of outer buoy of Red River, 1 male, 4.vi. 1969; 13 km SW Bigstone Point, 1 male, 11.vi. 1969; 26 km east north-east of Grand Rapids, 1 male, 13.vi. 1969; north-northeast of Reindeer Island, 1 female, 15.vi. 1969; 13 km southeast of Bigstone Point, 1 male, 3.ix. 1969; outer buoy of Red River, 1 male, 17.iii. 1970; off Grand Marais Point, 1 male, 17.iii. 1970; South Basin, 396 larvae, 1 pupa, 4.vi–31.x.1969; Narrows, 152 larvae, 1 pupa, 4.vi–31.x.1969; North Basin, 182 larvae, 4.vi–31.x.1969.

The males of the Lake Winnipeg population ( Fig. 4 ) conform well to the description given by Roback (1971: 177). The only exception is one male with the indication of an anal point ( Fig 4 D). This may only be a deformity possibly caused by mermithid infection or it may indicate that an additional species close to P. culiciformis is present. The female has 6–8 setae on anepisternum II, segment X with 20–30 setae, and 3–8 sensilla chaetica on each ta1 of p2 and p3.

Pupa (n = 10)

Cephalothorax. Thoracic horn ( Fig.12 C) 350–515, 430 µm long [ 518–547 µm in Roback (1980)]; 103–160, 119 µm wide; plastron plate diameter 62–104, 94 µm; apical constriction of horn chamber 24–65, 42 µm wide; length/width of horn 3.22–3.96, 3.64; width of plastron plate /width of horn 0.61–0.76, 0.67[0.50–0.57in Roback (1980)]; width of plastron plate/ width of constriction 1.88–3.08, 2.15.

Abdomen. Anal lobe ( Fig. 12 I) with 42–62, 50 spines on outer margin and 7–12, 10 spines on inner margin; dense row of relatively short spines posterolaterally.

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

Head capsule length 650–810, 757 µm (622) [ 580–680 µm in Moore & Moore (1978)].

Head. Antenna as in Fig. 13 C. Lengths of antennal segments 1–5 (µm): 155–176, 167; 16–21, 19; 4–7, 5; 2; 2. AR 5.17–6.84, 6.00 [4.2–6.0 in Moore & Moore (1978)]. Basal antennal segment 31–38, 36 µm wide; 4.31–5.15, 4.69 times as long as wide; ring organ 0.67–0.78, 0.73 from base; blade 23–31,26 µm long; accessory blade 18–26, 22 µm long. Apical style of second segment 6–10, 8 µm long. Mandible 162–178, 168 µm long [115–150 µm in Moore & Moore (1978), 192 µm in Roback (1980)]. Maxilla ( Fig.14 B) with lamelles of palpifer divided ending in triangular lamelles broadest at apex; lamelles of galea apparently undivided or perhaps with some divided. Maxillary palp ( Fig.14 F) 38–48, 42 µm long; 13–16, 14 µm wide; 1.90–2.33, 2.24 times as long as wide. Length of basal antennal segment/length of palp 3.60–4.40, 3.98. Hypopharyngeal pecten with 10–14, 11 teeth.

Abdomen. Claws of posterior parapods ( Fig.14 K) all relatively long and slender.

Remarks. The anal lobe of the pupa differ from that illustrated by Roback (1980, fig. 178) by having several small spines on the inner margin. However, the inner margin is curved in the same way and Roback had few associated immatures. The immatures from Lake Lacawac, Pennsylvania, are larger than the Lake Winnipeg population, while those from the Great Slave Lake described by Moore & Moore (1978) are generally smaller.

Distribution and ecology. The species was previously known from all over the Palaearctic Region except for North Africa, from the Near East, and in North America from Northwest Territories, British Columbia and Ontario to Kansas and Florida, California, Nevada and Arizona ( Oliver et al. 1990: 15, Spies 1999, Saether & Spies 2004). The species is primarily a northern lake form. The distribution in Lake Winnipeg is shown in Fig. 1 , the emergence pattern in Fig. 5 .

Figures

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

FIGURE 4. Procladius (H.) culiciformis (L.), male. A, B—cibarial pump, tentorium and stipes of male; C—thorax; D, Ehypopygium.

FIGURE 5. Procladius (H.) culiciformis (L.). 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, longer line = 51 – 100 specimens, 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.