Pest Fruit Flies of the World – Larvae


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

Bactrocera xanthodes (Broun)

Tephrites xanthodes Broun, Dacus xanthodes Broun

Body length 8–10mm; slender, elongate, tapering anteriorly (?). Integument unsclerotized, entirely whitish to yellowish, or partially sclerotized (mature larvae); sclerotization forming a transverse line beneath posterior spiracles (mature larvae), or forming a small heart-shaped patch of pigment below cuticle surface on ventral side of T1 (mature larvae) (V-shaped mark present on all NMNH specimens; not mentioned by WEH); 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 short, tapered; peg sensilla unbranched; other peg-sensilla-like structures absent. Stomal region: secondary lobes present, medial ones elongate, like oral ridges (6–7, small to large); margins of secondary lobes all entire; sclerotized stomal guards absent (?). Oral ridges present; number of oral ridges 17–24 (18–24~WEH; at least one NMNH specimen has 17); margins scalloped (moderately long, evenly spaced, "tapering" teeth; look scalloped to me). Accessory plates present (interlocking with oral ridges); number of accessory plates 12–19 (~~); margins serrated (with deeply serrated, evenly spaced teeth). Elongate, finger-like lobes arising above mandibles absent. Median oral lobe absent or not protruding. Labium broad.

Cephalopharyngeal skeleton. Mandibles: subapical teeth present (~LEC's SEM; WEH's statement that there is no subapical tooth is presumed to be erroneous); tooth much smaller than apical tooth, and delicate; with a single ventral tooth; 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 11–16; 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 2–3x longer than wide (range estimated, LEC coded about 2.5). Dorsal spiracular processes with numerous trunks arising from an elongate base (long processes). Number of dorsal spiracular processes 10–16. Number of ventral spiracular processes 10–16. Number of lateral spiracular processes 4–7. Area between posterior spiracles smooth.

Host plants. Anacardiaceae, Apocynaceae, Bromeliaceae, Caricaceae, Clusiaceae, Cucurbitaceae, Euphorbiaceae, Lecythidaceae, Malvaceae, Moraceae, Myrtaceae, Passifloraceae, Rutaceae, Sapindaceae, Sapotaceae, Solanaceae.

Part of plant attacked: fruit.

Biogeographic region. Australasian-Oceanian.

Specimens examined. Based on specimens from American Samoa, 3.v.82, breadfruit, 61588 (NMNH, n=6), and on description by White and Elson-Harris (1992; Cook Islands: ex Carica papaya).

Sources of data and SEM numbers: 247SEM.

Illustrations. • Cephalopharyngeal skeleton (lateral). • Head (anteroventral) SEM. • Stomal organ SEM. • Head (lateral) SEM. • Anterior spiracle SEM. • Caudal segment (posterior) SEM. • Caudal segment (lateral) SEM. • Posterior spiracles 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.’.