Melanagromyza aenea

Family

Subfamily

Genus

Species

Melanagromyza aenea (Meigen, 1830)

Mine

N/A. An internal stem-borer. Larva feeding inside the stem, pupariation internal.

Host Plants

• Urtica

Confusion Species

Other stem-boring taxa; the posterior spiracles of the larva/puparium allow positive determination.

Recording Grade

4

National Status

Nationally Scarce A.

Puparium

Whitish-yellow, posterior spiracles dark, separated by approximately their own diameter, each with 13-19 bulbs around a strong central horn. Length from 3.0 in male to 3.5mm in female.

Adult

Head: Frons 1.8-2.0x as wide as eye, orbits slightly projecting above eye in profile, more so at level of ors, with 2 strong ors, 3 or 4 (rarely 5) strong ori. Orbital setulae long, thick, numerous and entirely proclinate, in 2-4 rows. Eye in male with patch of pubescence at level of ors. Gena slightly deeper in centre below eye, 0.20-0.25x as high as eye. Cheek forming a distinct ring below eye. Orbits wide; lunule slightly higher than a semi-circle, sometimes with a slight central furrow. Ocellar triangle reaching to level of lower ors, sometimes to upper ori. Third antennal segment small, rounded, with short pubescence, not longer than the basal section of the arista.
Mesonotum: 2 strong dc (very rarely, a third may be present); acr in 8-10 rows, reducing to 5-6 at level of first dc. 1-2 dorsal scutellar setulae may be present near lateral scutellar setae.
Wing: Normal, hyaline. All veins brown. Ultimate section of vein M₄ 0.75 (average) that of the penultimate. Costal sections (2-4) with an average ratio of 100:26:26. Length 2.1-2.4 mm in male, 2.6-2.9 mm in female.
Colour: Frons matt black. Orbits and ocellar triangle weakly shining. Lunule slightly paler than frons. Gena brownish-black, palpi black. Mesonotum greyish-black, matt, when viewed from front, weakly shining when viewed from behind. Abdomen distinctly shining, metallic, greenish. Calypter greyish, margin dark brown to black, fringe brownish-black, sometimes pale brown in parts. Legs dark, brownish-black with 2 posterolateral setae on mid tibia.
Male genitalia: Surstylus possessing a few long setae and several spines on inner surface; basiphallus U-shaped; basal bladder of mesophallus with slight upward curvature; distiphallus with distinct areas of spiculae when viewed from above; distal tubule relatively strong.
Female genitalia: Egg guide acute apically, 5x as long as maximum width, medial membrane with numerous sensilla on inner margin, numerous small scales present in apical half.