Megaselia aurea (Aldrich 1896)

Megaselia (Megaselia) aurea (Aldrich)

Phora aurea Aldrich, 1896, p. 477 [♂ ♀; St. Vincent, B.W.I.].—Coquillett, 1900 p. 253.

Aphiochaeta aurea (Aldrich).—Brues, 1904, p. 365, pi. VII: fig. 35.—Malloch, 1912, p. 467.

Megaselia (M.) aurea (Aldrich).—Borgmeier, 1962b, p. 294, 306 [key]; 1966, pp. 2, 15.

Aphiochaeta rubriventris Borgmeier, 1925b, p. 156, pl. v: fig. 22.

Holotype female and 4 paratypes females (USNM), one paratype female (CTB), 1 paratype male (MCZ), St. Vincent, B.W.I.

Additional notes to my redescription (1966) are as follows.

MALE.—Length 1.3–2.4 mm. Su unequal. Hypopygium (Figure 38) of medium size, dark brown, on each side with numerous short hairs and one moderate bristle below. Ventral plate large, broadly rounded. Anal segment long, yellow, with short hairs and 2 pairs of longer ones near dorsal edge of tergite, which are about as long as the apical hairs. Hind femur (Figure 40) slender, more than 3 times as long as broad, on basal half of ventral edge with 6 conspicuous curved hairs, the longest is about one-half of femural width. Costa (male from Dominica) 0.65, ratio of segments 21:19:4.

FEMALE.—Length 1.5–3 mm. The structure of the abdominal tergites can best be observed in pregnant individuals preserved in alcohol (Figure 39). Second tergite moderately elongated, reaching sides, well chitinized; 3rd shorter than 2nd, weakly chitinized, the outlines ill defined, at each side with a transverse oval whitish area which is shining and often surrounded by a dark area; 4th and 5th rudimental, nearly membranous but recognizable by the very short pubescence, 4th slightly transverse, 5th subquadrate; 6th well chitinized, rectangular, longer than broad. The color of the abdominal segments 1–6 is highly variable (the terminal segments 7–10 are always black):

In a paratype, tergite 1 is reddish brown; 2 reddish brown at middle, black laterally; 3 black-brown; 4–5 black with a deep red tinge; 6 deep black; sides of abdomen deep red above, black below; venter yellow.

In specimens from Grenada, W.I., tergites 1–5 are orange, 6 is black; sometimes also 2–3 are black laterally; in one specimen 1–4 are orange, 5–6 black.

In specimens from Dominica, W.I., tergites 1–3 are brown, 2 sometimes yellow anteriorly; 4 is orange; 5 dark brown, sometimes orange; 6 black, venter orange, often black laterally.

In specimens from Brazil (Rio de Janeiro; Belem, Pará), Bolivia, Costa Rica, and United States (Florida), tergites 1–6 are orange; in 2 specimens from Costa Rica 6 is black at sides, yellow at middle.

Costa in paratype 0.62 of wing length, ratio of segment 27:22:5; in specimens from Dominica the first section is generally equal to 2 + 3 or shorter; in specimens from Rio de Janeiro, Bolivia, Costa Rica, Florida, 1 is longer than 2 + 3.

MATERIAL EXAMINED.—Besides the material listed in a previous paper (1966) I have seen 6 pinned males and 25 females, and 50 males and 45 females in alcohol, from the following localities of Dominica: Clarke Hall, Manets Gutter, Fond Figues River, S. Chiltern Est. and Pont Casse, January-March 1965 (W. W. Wirth).

Megaselia aurea is a species of scuttle flies (insects in the family Phoridae).