Melanagromyza lappae

Family

Subfamily

Genus

Species

Melanagromyza lappae (Loew, 1850)

Mine

Initially, a short mine is produced in the leaf, which quickly joins the midrib, with the larva then feeding down into the stem; often many larvae per stem. Pupariation internal. Warrington (2018b) discussed the larval habits in detail.

Host Plants

• Arctium

Confusion Species

N/A.

Recording Grade

4

National Status

Nationally Scarce B.

Puparium

Whitish-grey, posterior spiracles dark, almost adjoining, each with 16-22 bulbs around the strong central horn. Length from 3.1mm in male to 4.9mm in female.

Adult

Head: Frons 1.7-2.1x as wide as eye, orbits projecting above eye in profile, with 2 strong ors, 2-6 ori. Orbital setulae numerous, 2-4 rows, both proclinate and reclinate. Eye slightly pubescent in male, in female bare (some specimens may possess sparse pubescence). Gena deeper in centre below eye, 0.20-0.25x as high as eye. Cheek forming a distinct narrow ring below eye. Orbits relatively broad; lunule broad, semi-circular, frequently with a slight central furrow. Ocellar triangle normal, reaching to lower ors, sometimes to upper ori. Third antennal segment small, rounded, sometimes more axe-shaped, with short but distinct pubescence, not longer than the basal section of the arista.
Mesonotum: 2 strong dc (rarely, a 3rd and 4th dc may be present, situated between 1st and 2nd dc or after 2nd dc); acr in 8-10 rows, reducing to 6-8 at level of first dc. 1-2 dorsolateral to dorsal scutellar setulae irregularly present close to lateral scutellar setae.
Wing: Hyaline, all veins brownish. Ultimate section of vein M₄ 0.72 (average) that of the penultimate. Costal sections (2-4) with an average ratio of 100:23:21. Length 2.5-2.8 mm in male, 3.2-3.6 mm in female.
Colour: Frons matt, black but with slight sub-shine. Orbits paler than frons, shining adjoining frons, matt adjoining eye, ocellar triangle weakly shining. Lunule slightly lighter than frons. Gena brownish with palpi black. Mesonotum metallic, coppery, abdomen mostly brilliantly metallic, greenish (more so in female). Calypter greyish-white, margin from very pale brown to medium brown, fringe pale, whitish. Legs dark, brownish-black with 2 posterolateral setae on mid tibia (occasionally posterior seta weak or absent).
Male genitalia: Surstylus possessing several long setae and spines on inner surface; basiphallus U-shaped; basal bladder of mesophallus with slight upward curvature; distiphallus with distinct areas of strong, dark spiculae when viewed from above; distal tubule relatively strong and wide.
Female genitalia: Egg guide narrower, slightly curved, 6.0-6.4x as long as maximum width, medial membrane without sensilla, inner margin with a few scattered sensilla basally.