Pest Fruit Flies of the World – Larvae
Trypeta fratria Loew, Trypeta liogaster Thomson
Parsnip leaf miner. Body length 5.3–8.2mm (8.0~WEH); elongate-cylindrical, or elongate, swollen anteriorly (?). Integument unsclerotized, entirely whitish to yellowish. Caudal ridge absent. Mature larvae unable to jump.
Head. Head deflexed, laterally flattened, thorax hood-like; cephalic lobes slightly developed, or not developed. Antenna 1-segmented. Stomal organ: primary lobe large, elongate-flattened; number of peg sensilla none apparent; other peg-sensilla-like structures absent. Stomal region: secondary lobes absent; sclerotized stomal guards absent (?check for scl. oral ridges). Oral ridges present; number of oral ridges 3–9 (3–5 long + 4 short); margins entire, or serrate (mostly). Accessory plates absent (LEC). Elongate, finger-like lobes arising above mandibles absent. Median oral lobe absent or not protruding. Labium narrow.
Cephalopharyngeal skeleton. Mandibles: subapical teeth present ((Phillips' fig. erroneous); tooth about the same size as apical tooth; with medial and lateral teeth; base stout, nearly perpendicular to a line from ventral part of base to apex of mandible. Parastomal bars short and stout, or apparently absent. Dental sclerites apparently absent, not visible in lateral view.
Spinules and creeping welts. Dorsal spinules on segments T1-A1, or T1-A2.
Caudal segment (a8) and anal lobes. Sensilla on caudal segment 6 or fewer pairs visible (5 pairs). Dorsal caudal sensilla obvious, on a single papilla or tubercle. Intermediate caudal sensillum I3 absent or visible only with great difficulty. Lateral caudal sensillum absent or visible only with great difficulty. Intermediate caudal sensilla I1a&b obvious, on a single papilla or tubercle, not bifid apically. Intermediate caudal sensillum I2 obvious (?). Intermediate caudal sensilla I1a&b and I2 on a single tubercle. Ventral caudal sensilla absent or visible only with great difficulty. Anal lobes plainly visible, but not strongly protuberant, or indistinct, retracted into anal slit, or absent (?); simple.
Anterior spiracles. Anterior spiracle not strongly elevated, margin long and convex. Anterior spiracular tubules 14–22 (14–17~WEH); in a single uniform row.
Posterior spiracles. Posterior spiracular area set off by a ring of tubercles and a distinct groove. Posterior spiracles: slits 3–3.5x longer than wide (about,~WEH). Dorsal spiracular processes with only 1 or 2 trunks (short). Number of dorsal spiracular processes 1–2 (2~Phillips; usu. 1 on her slides). Number of ventral spiracular processes 1–2 (2~Phillips; usu. 1 on her slides). Number of lateral spiracular processes 1–2 (2~Phillips; usu. 1 on her slides). Dorsal and ventral spiracular processes: ratio of number of tips to number of trunks 0.75–1.5 (range estimated, LEC coded 1).
Host plants. Apiaceae (parsnip, celery, parsley and others), Asteraceae (Prenanthes canadensis).
Part of plant attacked: leaf.
Biogeographic region. Nearctic.
Specimens examined. Based on description by Phillips (1946).
Sources of data and SEM numbers: 404.
Illustrations. • Cephalopharyngeal skeleton, spiracles, caudal segment. • Head (anteroventral) SEM (minimum magnification). • Head (anteroventral) SEM (medium magnification). • Head (anteroventral) SEM (maximum magnification). • Antenna, maxillary palp, stomal organ SEM. • Head (lateral) SEM. • Aanterior 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. http://delta-intkey.com’.