Euphranta canadensis

Description

Euphranta canadensis is not the only species in its genus, but it is the only species of Euphranta with available larval morphological data, so the diagnosis (taken from Carroll et al. 2006), contains both genus- and species-level characters. It can be distinguished from other fruit flies by the following specific characteristics for the third instar:

Body. Larvae medium-sized. Body length 7–8mm; stout, elongate, tapering anteriorly. Integument unsclerotized, entirely whitish to yellowish. Caudal ridge absent. Mature larvae able to jump.

Head. Head of normal shape; cephalic lobes slightly developed, or not developed. Antenna 2-segmented. Stomal organ: primary lobe rounded, protuberant; number of peg sensilla two (small); peg sensilla unbranched; other peg-sensilla-like structures absent. Stomal region: secondary lobes absent; sclerotized stomal guards absent. Oral ridges present; number of oral ridges 15–17 (short); margins dentate (long, sharply tapered, well spaced teeth, becoming less serrated towards outer edge). Accessory plates absent. Elongate, finger-like lobes arising above mandibles absent. Median oral lobe absent or not protruding. Labium narrow.

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.

Anterior spiracles. Anterior spiracle convex to flat. Anterior spiracular tubules 14–16; in a single uniform row.

Spinules and creeping welts. Dorsal spinules on segments T1-A8.

Caudal segment (a8) and anal lobes. Sensilla on caudal segment 10 pair, with at least 7 pair 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, not on a papilla or tubercle. Anal lobes plainly visible, but not protuberant; simple.

Posterior spiracles. Posterior spiracular area not distinctly set off from caudal segment. Posterior spiracles: slits 3.5x longer than wide (about). Dorsal spiracular processes with fewer trunks radiating from a short or semicircular base (medium processes). Number of dorsal spiracular processes 3–5. Number of ventral spiracular processes 3–5. Number of lateral spiracular processes 2–4. Area between posterior spiracles smooth.

Host plants

Family	Genus
Grossulariaceae	Ribes

Part of plant attacked: fruit.

Biogeographic region and distribution

Nearctic

Canada and USA (n. British Columbia east to New Brunswick, south to California, New Mexico, Michigan and Maine).
 

Adult taxonomy

Euphranta (Rhacochlaena) canadensis (Loew)
Trypeta canadensis Loew 1873: 235.—Canada. HT ♀ MCZ.
Epochra lunifera Hering 1940: 5.—USA. Washington: Sumner. HT ♀ BMNH.
 

References

Carroll, L. E., 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.

White, I. M., and M. M. Elson-Harris. 1992. Fruit flies of economic significance: their identification and bionomics. CAB International; Wallingford, UK. 601 p.