Ablabesmyia (Karelia) philosphagnos Beck et Beck

Ablabesmyia (Karelia) philosphagnos Beck et Beck

(Figs 2 B; 3 B; 4 B, I; 5 A, D, J)

Material examined. CANADA: Ontario, Sudbury, large pool in rock outcrop beside Highway 17.4 miles east of post office, male reared from larva, 17.vi. 1967, J. Martin; British Columbia, Haney Forest, Marion Lake, in Mougeotia on lake bottom, 1 male reared from larva, 1 male reared from pupa, 15.vii.1967, A. L. Hamilton and O. A. Saether.

Although no specimens of this species were found in Lake Winnipeg, three reared specimens from Ontario and British Columbia are of particular interest. The adults all have darker coloration than typical A. (K.) philosphagnos Beck et Beck with tergites I–III not clear, but with mesal infuscations as on tergites IV and V. These specimens may represent a species or subspecies separate from A. (K.) philosphagnos. They are, however, not separable from A. (K.) philosphagnos on the basis of the description in Beck and Beck (1966: 331) and Roback (1971: 362, 1985: 176).

Pupa (n = 3). Total length 5.68–6.86 mm. Exuviae pale yellowish brown.

Cephalothorax. Thoracic horn (Fig. 2 B) 650–711 µm long, 313–325 µm wide; 2.08–2.19 times as long as wide; respiratory duct (Fig. 2 B) forms a rounded "T" at apex. Thoracic comb (Fig. 2 B) consisting of 13–18 apically pointed spines, the longest 35–40 µm.

Abdomen. Anal lobe (Fig. 3 B) 1.14–1.25 times as long as wide; outer margin distad of distal setae with 12–16 distinct spinules.

Fourth instar larva (n = 1–2). Head capsule length 1.08–1.18 m.

Head. Antenna as in Fig. 4 B. Lengths of antennal segments (in µm): 564–601, 94–101, 8–9, 4. AR 5.11–5.18. Basal antennal segment 33–34 µm wide, ring organ 0.48 from base, blade 95–102 µm long, accessory blade 92–98 µm long. Apical style of second segment 10–11 µm long, accessory style 5–6 µm long. Mandible (Fig. 5 J) 200 µm long. Maxilla as in Fig. 5 A. Maxillary palp (Fig.5 D) 2-segmented with a partially sclerotized third basal segment; basal segment 34–41 µm long, 17–18 µm wide; apical segment 68–70 µm long, 12–13 µm wide. Ligula (Fig. 4 I) 120–130 µm long. Paraglossa 40–58 µm long. Hypopharyngeal pecten with 15–17 teeth.

Abdomen. Procercus 150–170 µm high, 50–56 µm wide, 3.00–3.04 times as high as wide. Anal setae 780–834 µm long, supraanal seta 354–380 µm long, supraanal seta/anal setae 0.45–0.46. Posterior parapods 711–740 µm long, without any darker claws.

Distribution and ecology. The species is known from British Columbia, Ontario and New Brunswick and Pennsylvania to North Carolina, Mississippi and Florida (Roback 1985: 176, Oliver et al. 1990: 10; Hudson et al. 1990: 4; Epler 2003, 2010; Caldwell 2009; Ashe & O’Connor 2009: 123).