Pest Fruit Flies of the World – Larvae


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

Rhagoletis striatella Wulp

Body length 8.5–10mm; elongate-cylindrical (?). Integument unsclerotized, entirely whitish to yellowish. Caudal ridge absent. Mature larvae unable to jump.

Head. Head of normal shape; cephalic lobes slightly developed. Antenna 2-segmented. Stomal organ: primary lobe rounded, protuberant; number of peg sensilla one; peg sensilla unbranched; other peg-sensilla-like structures absent. Stomal region: secondary lobes absent; sclerotized stomal guards present; number of sclerotized stomal guards 2 (large, with teeth on their sides). Oral ridges present (very poorly developed), or absent; number of oral ridges (when present) 4–8 (not pronounced); margins rounded, more like reticulation than ridges (?). Accessory plates present (not pronounced), or absent; number of accessory plates (when present) 1–5; margins unserrated. 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-A4.

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 a single tubercle (?). Ventral caudal sensilla obvious, on a papilla or tubercle. Anal lobes very protuberant; bifid.

Anterior spiracles. Anterior spiracle elevated, margin concave medially, appearing bilobed. Anterior spiracular tubules 30–38 (range estimated, LEC coded 33–35); in a single uniform row, or in a single irregular row (?).

Posterior spiracles. Posterior spiracular area not distinctly set off from caudal segment. Dorsal spiracular processes with numerous trunks arising from a short or semicircular base (long processes). Number of dorsal spiracular processes 6–10 (?). Number of ventral spiracular processes 6–10 (?). Number of lateral spiracular processes 6–10 (?). Area between posterior spiracles smooth.

Host plants. Solanaceae (Physalis spp.).

Part of plant attacked: fruit.

Biogeographic region. Nearctic, Neotropical.

Specimens examined. Based on a single specimen from Mexico, Oct. 10, 1944, lot no.44–25220, Lar[edo] Texas no. 34707 (NMNH) and on descriptions by Berg (1979) and Kandybina(l977:195(tr.)).

Sources of data and SEM numbers: 381.

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.’.