Pest Fruit Flies of the World – Larvae
Trypeta canadensis Loew, Epochra lunifera Hering
Currant fruit fly, Yellow currant fly, Currant and gooseberry maggot. Body length 6–9mm (range estimated, LEC coded as 7–8); stout, elongate, tapering anteriorly (?). Integument unsclerotized, entirely whitish to yellowish. Caudal ridge absent. Mature larvae able to jump.
Head. Head of normal shape; cephalic lobes slightly developed, or not developed. Antenna 2-segmented. Stomal organ: primary lobe rounded, protuberant; number of peg sensilla two (small); peg sensilla unbranched; other peg-sensilla-like structures absent. Stomal region: secondary lobes absent; sclerotized stomal guards absent. Oral ridges present; number of oral ridges 15–17 (short); margins dentate (long, sharply tapered, well spaced teeth, becoming less serrated towards outer edge). Accessory plates absent. Elongate, finger-like lobes arising above mandibles absent. Median oral lobe absent or not protruding. Labium narrow.
Cephalopharyngeal skeleton. Mandibles: subapical teeth absent (~Phillips' fig.;?); base stout, nearly perpendicular to a line from ventral part of base to apex of mandible. Parastomal bars elongate, free from hypopharyngeal sclerite. Dental sclerites apparently absent, not visible in lateral view (?).
Spinules and creeping welts. Dorsal spinules on segments T1-A8.
Caudal segment (a8) and anal lobes. Sensilla on caudal segment 10 pairs, with at least 7 pairs visible under dissecting microscope. Intermediate caudal sensillum I2 obvious. Intermediate caudal sensilla I1a&b and I2 on separate papillae or tubercles. Ventral caudal sensilla absent or visible only with great difficulty, or obvious, but not on a papilla or tubercle (?). Anal lobes plainly visible, but not strongly protuberant; simple.
Anterior spiracles. Anterior spiracle elevated, margin convex to straight. Anterior spiracular tubules 14–16 (!Phillips 1946); in a single uniform row (?).
Posterior spiracles. Posterior spiracular area not distinctly set off from caudal segment. Posterior spiracles: slits 3–4x longer than wide (range estimated, LEC coded about 3.5). Dorsal spiracular processes with a few trunks radiating from a short or semicircular base (medium processes). Number of dorsal spiracular processes 3–5. Number of ventral spiracular processes 3–5. Number of lateral spiracular processes 2–4. Area between posterior spiracles smooth.
Host plants. Grossulariaceae.
Part of plant attacked: fruit.
Biogeographic region. Nearctic.
Specimens examined. Based on description by White and Elson-Harris (1992; Wyoming (n=2)).
Sources of data and SEM numbers: 344SEM.
Illustrations. • Cephalopharyngeal skeleton, spiracles, caudal segment. • Head (anteroventral) SEM. • Stomal organ SEM. • Head (lateral) SEM. • Anterior spiracle SEM. • Caudal segment (posterior) SEM. • Posterior spiracles SEM. • Caudal segment (lateral) SEM. • Anal lobes SEM.
Cite this publication as: ‘L.E. Carroll, A.L. Norrbom, M.J. Dallwitz, and F.C. Thompson. 2004 onwards. Pest fruit flies of the world – larvae. Version: 8th December 2006. http://delta-intkey.com’.