Pest Fruit Flies of the World – Larvae

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L.E. Carroll, A.L. Norrbom, M.J. Dallwitz, and F.C. Thompson

Bactrocera umbrosa (Fabricius)

Dacus umbrosus Fabricius, Bactrocera fasciatipennis Doleschall, Dacus diffusus Walker, Dacus fascipennis Wiedemann, Dacus frenchi Froggatt, Strumeta conformis Walker

Body length 8–11mm; slender, elongate, tapering anteriorly (?). Integument unsclerotized, entirely whitish to yellowish, or partially sclerotized; sclerotization forming a small heart-shaped patch of pigment below cuticle surface on ventral side of T1 (mature larvae); sclerotized process(es) on caudal segment absent. Caudal ridge present. Mature larvae able to jump.

Head. Head of normal shape; cephalic lobes well developed. Antenna 2-segmented. Stomal organ: primary lobe small, round; number of peg sensilla three (small); peg sensilla with few short branches; other peg-sensilla-like structures absent. Stomal region: secondary lobes present, short, leaf-like (5 preoral lobes with the anterior lobe very large, forming a single lobe above the mandible); margins of secondary lobes all entire; sclerotized stomal guards absent (?). Oral ridges present; number of oral ridges 16–21; margins serrate (very short, broad, blunt teeth). Accessory plates present (small, shell shaped); margins unserrated, or serrated (with very few 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 elongate, forming a more oblique angle. Parastomal bars elongate, free from hypopharyngeal sclerite. Dental sclerites present, posterior to mandibles.

Spinules and creeping welts. Dorsal spinules on segments T1-T3.

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, or elevated, margin concave medially, appearing bilobed (?). Anterior spiracular tubules 17–21; 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 3–4x longer than wide (range estimated, LEC coded about 3.5). Dorsal spiracular processes with numerous trunks arising from a short or semicircular base (medium processes). Area between posterior spiracles smooth.

Host plants. Cucurbitaceae, Moraceae, Passifloraceae, Rutaceae.

Part of plant attacked: fruit.

Biogeographic region. Oriental, Australasian-Oceanian.

Specimens examined. Based on description by White and Elson-Harris (1992; Malaysia: ex Artocarpus integer).

Sources of data and SEM numbers: 236SEM.

Illustrations. • Cephalopharyngeal skeleton (lateral).


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’.

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