Pest Fruit Flies of the World – Larvae


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

Dirioxa pornia (Walker)

Trypeta pornia Walker, Rioxa confusa Hardy, Trypeta musae Froggatt

Island fruit fly, Boatman fly, South Sea fly. Body length 5.5–8.5mm; slender, elongate, tapering anteriorly, or stout, elongate, tapering anteriorly (?). Integument unsclerotized, entirely whitish to yellowish. Caudal ridge ?.

Head. Head of normal shape; cephalic lobes well developed, or moderately developed. Antenna 2-segmented. Stomal organ: primary lobe small, round; number of peg sensilla one (small); peg sensilla unbranched (?); other peg-sensilla-like structures absent. Stomal region: secondary lobes present, medial ones elongate, like oral ridges (5–6, long, resembling small oral ridges); margins of secondary lobes more than one lobe with serrate margins; sclerotized stomal guards absent (?). Oral ridges present; number of oral ridges 13–18 (very long); margins scalloped (long, parallel sided, bluntly rounded teeth;deep). Accessory plates present (long, interlocking with outer edges of oral ridges); number of accessory plates 10–11 (~+~); margins serrated (deeply serrated). Elongate, finger-like lobes arising above mandibles absent. Median oral lobe absent or not protruding (bilobed, but not like P. poeciloptera). 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.

Caudal segment (a8) and anal lobes. 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; bifid ("unequally bilobed").

Anterior spiracles. Anterior spiracle elevated, margin concave medially, appearing bilobed (broad, fan-shaped~WEH). Anterior spiracular tubules 9–13; 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 23x longer than wide (range estimated, LEC coded about 2.5). Dorsal spiracular processes with numerous trunks arising from a short or semicircular base (long processes). Number of dorsal spiracular processes 10–15. Number of ventral spiracular processes 10–15. Number of lateral spiracular processes 6–9. Area between posterior spiracles smooth.

Host plants. Anacardiaceae, Ebenaceae, Fabaceae, Lauraceae, Moraceae, Musaceae, Myrtaceae, Passifloraceae, Rosaceae, Rutaceae, Sapotaceae.

Part of plant attacked: fruit (possibly/probably secondary).

Biogeographic region. Australasian-Oceanian.

Specimens examined. Based on description by White and Elson-Harris (1992; Australia: Queensland, ex Chrysophyllum cainito and Planchoniella australis).

Sources of data and SEM numbers: 342SEM.

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.’.