Stilobezzia (Eukraiohelea) amnigena (Macfie)

William L. Grogan, Jr., Hribar, Lawrence J., Murphree, C. Steven & Cilek, James E., 2010, New records of biting and predaceous midges from Florida, including species new to the fauna of the United States (Diptera: Ceratopogonidae), Insecta Mundi 2010 (147), pp. 1-59 : 38-39

Stilobezzia (Eukraiohelea) amnigena (Macfie)

Eukraiohelea amnigena Macfie, 1935: 56 ( Brazil) .

Stilobezzia (Eukraiohelea) amnigena: Lane and Forattini 1958: 203 (combination); Wirth and Spinelli 1992a: 346 (review of New World Eukraiohelea Ingram and Macfie ; Florida and South Carolina records); Borkent and Grogan 2009: 22 (in Nearctic catalog; distribution).

Stilobezzia (Eukraiohelea) elegantula (Johannsen) : Johannsen 1907: 109 (in part); Wirth 1953a: 62 (in part; review of North American Stilobezzia Kieffer ).

Discussion. Wirth and Spinelli (1992a) noted that Wirth (1953a) and Wirth and Grogan (1981) identified some males of S. amnigena from Florida as S. elegantula . Wirth and Spinelli provided illustrations of the male genitalia of both species and noted that in males of S. amnigena , sternite 9 is concave caudomedially, the apicolateral processes on tergite 9 are slender, the gonostylus is swollen in mid portion, and the parameres have partially or entirely separated basal apodemes and the slender distal portions with narrow apices that are recurved 90 o ventrally. In males of S. elegantula , sternite 9 is convex caudomedially, the apicolateral processes on tergite 9 are broader, the parameres have longer attached basal apodemes with the distal portions very broad on their distal halves and their tips are abruptly tapered and ventrally directed. In their key to American species of Stilobezzia (Eukraiohelea), Wirth and Spinelli (1992a) stated that females of S. amnigena are large, with “wing length about 2.00; costal ratio 0.80.” For females of S. elegantula , they gave mean and ranges of wing length of 1.40 (1.36-1.46 mm, n=5) and costal ratio 0.75 (0.75-0.78). As noted in our account of S. elegantula below, we measured wing lengths and costal ratios of 35 females of that species from Alachua Co. as well as three females from Alachua and two females from Wakulla counties of S. amnigena . Our data confirm that females of S. amnigena are indeed large with mean/range of wing length 1.90 (1.79-2.02 mm, n=5), however, their costal ratio was 0.75 (0.74-0.77, n=5), and therefore, we suggest that costal ratio is not a significant distinguishing feature between these two species. Wirth and Spinelli (1992a) examined Florida specimens of S. amnigena from Alachua, Dade, Jefferson, Leon, Putnam, Santa Rosa and Wakulla counties. We provide an additional record from Wakulla Co.

New records. Wakulla Co., Wakulla Springs State Park, Lodge Road, 25 May 2004, S. Murphree, CDC light trap with UV wand, 2 females (WLGC).