Pest Fruit Flies of the World – Larvae
Trirhithrum nigerrimum var. coffeae Bezzi
Body length 5.5–9.5mm (range estimated, LEC coded as small - medium); slender, elongate, tapering anteriorly, or stout, elongate, tapering anteriorly (?). Integument unsclerotized, entirely whitish to yellowish. Caudal ridge present. Mature larvae able to jump.
Head. Head of normal shape; cephalic lobes slightly developed. Antenna 2-segmented. Stomal organ: primary lobe small, round; number of peg sensilla one, or two; peg sensilla unbranched; other peg-sensilla-like structures absent. Stomal region: secondary lobes present, short, leaf-like (reduced); number of secondary lobes 1, or 2 (subtending lobe is fused with primary lobe); margins of secondary lobes one lobe with serrate margins, or more than one lobe with serrate margins; sclerotized stomal guards absent. Oral ridges present; number of oral ridges 7–9; margins entire, or serrate. Accessory plates present; number of accessory plates 3–4. Elongate, finger-like lobes arising above mandibles absent. Median oral lobe absent or not protruding. Labium broad (?).
Cephalopharyngeal skeleton. Parastomal bars elongate, free from hypopharyngeal sclerite (?). Dental sclerites present, posterior to mandibles (?).
Spinules and creeping welts. Dorsal spinules on segments ?.
Caudal segment (a8) and anal lobes. Sensilla on caudal segment 10 pairs, with at least 7 pairs visible under dissecting microscope. 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 7–11; in a single uniform row.
Posterior spiracles. Posterior spiracular area not distinctly set off from caudal segment. Dorsal spiracular processes with a few trunks radiating from a short or semicircular base (medium processes). Number of dorsal spiracular processes 11–15 (range estimated, LEC coded 13). Number of ventral spiracular processes 6–8 (range estimated, LEC coded 7). Number of lateral spiracular processes 1–4. Dorsal and ventral spiracular processes: ratio of number of tips to number of trunks 1.5–2 (range estimated, LEC coded 1.7). Area between posterior spiracles smooth.
Host plants. Rubiaceae.
Biogeographic region. Afrotropical.
Specimens examined. Based on specimens from Togo, 1981, G.J. Steck (n=3).
Sources of data and SEM numbers: LEC from plate only; i96.
Illustrations. • 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’.