Pest Fruit Flies of the World – Larvae
Dictya cancellaria Fabricius
Guava fruit fly. Body length 7–11mm (7.0–9.0~WEH; 7.7–11.0~Steck et al.); stout, elongate, tapering anteriorly. Integument unsclerotized, entirely whitish to yellowish. Caudal ridge absent. Mature larvae unable to jump.
Head. Head of normal shape; cephalic lobes moderately developed. Antenna 2-segmented. Stomal organ: primary lobe large, elongate-rounded; number of peg sensilla two, or three, or four or more; peg sensilla unbranched; other peg-sensilla-like structures present (with small, sharply pointed spinules scattered over surface of stomal sensory organ and adjacent preoral lobe). Stomal region: secondary lobes absent; sclerotized stomal guards absent (?). Oral ridges present; number of oral ridges 6–10 (6–9~WEH;6–10~Steck et al.); margins entire, or serrate (1~WEH; 1/2~LEC?). Accessory plates present (well defined); number of accessory plates 8–9 (~~); 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-T3, or T1-A1, or T1-A2, or T1-A3, or T1-A4, or T1-A5, or T1-A6 (3~WEH; 5/6/7/8/9~Steck et al.-check!).
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 separate papillae or tubercles. 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, or grooved, or bifid (slightly 2/3~WEH; 1/2/3~Steck et al.).
Anterior spiracles. Anterior spiracle elevated, margin convex to straight, or elevated, margin concave medially, appearing bilobed. Anterior spiracular tubules 11–18 (14–18~WEH; 11–18~Steck et al); 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 4.5–5.5x longer than wide (range estimated, LEC coded about 5). Dorsal spiracular processes with numerous trunks arising from an elongate base (long processes). Number of dorsal spiracular processes 14–20. Number of ventral spiracular processes 14–20. Number of lateral spiracular processes 6–10. Area between posterior spiracles smooth.
Linear discriminant functions. Anastrepha striata vs. A. bistrigata: C = 23.5log(BAS) 0.75(ANS) 0.63(TRK) 15: C greater than 0.
Host plants. Anacardiaceae, Annonaceae, Combretaceae, Ebenaceae, Euphorbiaceae, Lauraceae, Myrtaceae, Rosaceae, Rutaceae, Sapotaceae, Solanaceae.
Part of plant attacked: fruit.
Biogeographic region. Neotropical.
Specimens examined. Based on descriptions of Steck et al. (1990 and unpublished data; Mexico: Chiapas (n=?, progeny of single females), and White and Elson-Harris (1992; Suriname, ex Psidium guajava).
Sources of data and SEM numbers: combined data.
Illustrations. • Cephalopharyngeal skeleton, spiracles. • Cephalopharyngeal skeleton (lateral). • Head (anteroventral) SEM. • Stomal organ SEM. • Head (lateral) SEM. • Anterior spiracle SEM. • Caudal segment (posterior) SEM. • Posterior spiracles SEM. • Caudal segment (posterior) 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’.