Pest Fruit Flies of the World – Larvae
Dacus serpentinus Wiedemann, Urophora vittithorax Macquart
Sapote fruit fly, Serpentine fruit fly. Body length 7.5–10.3mm (7.5–9.0~WEH; 8.1–10.3~Steck et al.); stout, elongate, tapering anteriorly. Integument unsclerotized, entirely whitish to yellowish. Caudal ridge absent. Mature larvae unable to jump.
Head. Head of normal shape; cephalic lobes moderately developed. Antenna 2-segmented. Stomal organ: primary lobe large, elongate-rounded; number of peg sensilla three (large (2 long and tapering, 1 short and peg-like)); peg sensilla unbranched; other peg-sensilla-like structures present. Stomal region: secondary lobes absent; sclerotized stomal guards absent (?). Oral ridges present; number of oral ridges 8–14 (8–12~WEH; 9–14~Steck et al.); margins entire, or serrate, or emarginate (irregularly 2/5~WEH; 1/2~LEC?). Accessory plates present (large); number of accessory plates 6–10 (about 10~WEH; 6–9~Steck et al.); margins unserrated, or serrated (anterior ones with small serrations). Elongate, finger-like lobes arising above mandibles absent. Median oral lobe absent or not protruding. Labium broad.
Cephalopharyngeal skeleton. Mandibles: subapical teeth absent; 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-T2, or T1-T3 (3~WEH; 2~Steck et al.).
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, or grooved, or bifid (obviously 2/3~WEH; 1/2/3~Steck et al.).
Anterior spiracles. Anterior spiracle elevated, margin convex to straight, or elevated, margin concave medially, appearing bilobed. Anterior spiracular tubules 13–19 (13–18~WEH; 13–19~Steck et al.); in a single uniform row, or in a single irregular row (?).
Posterior spiracles. Posterior spiracular area not distinctly set off from caudal segment. Posterior spiracles: slits 2.5–3.5x longer than wide (about2.5–3.0~WEH; 2.5–3.5~Steck et al.). Dorsal spiracular processes with numerous trunks arising from a short or semicircular base, or with a few trunks radiating from a short or semicircular base (short processes). Number of dorsal spiracular processes 6–9. Number of ventral spiracular processes 6–9. Number of lateral spiracular processes 4–6. Area between posterior spiracles smooth.
Host plants. Anacardiaceae, Annonaceae, Apocynaceae, Clusiaceae, Ebenaceae, Euphorbiaceae, Flacourtiaceae, Lauraceae, Malpighiaceae, Moraceae, Myrtaceae, Rosaceae, Rutaceae, Sapotaceae.
Part of plant attacked: fruit.
Biogeographic region. Neotropical.
Specimens examined. Based on descriptions by Steck et al. (1990 and unpublished data; Mexico: Chiapas (n=?, progeny of single females), and White and Elson-Harris (1992: Surinam: ex Chrysophyllum cainito).
Sources of data and SEM numbers: combined data.
Illustrations. • Cephalopharyngeal skeleton, spiracles. • Cephalopharyngeal skeleton, spiracles, caudal segment (posterior). • Cephalopharyngeal skeleton (lateral). • 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’.