Zavreliella undetermined

Zavreliella sp.

(Figs. 22-26)

Diagnosis: The unnamed larva can be separated from others by the dark brown postmentum, and the ventromentum plate which is subequal to the mentum in width.

Description: Larva (n = 2)

Total length 5.0- 6.1 mm. Head capsule 350- 360 µm long, 240-250 µm wide. Cephalic index 0.7.

Coloration: Head capsule yellow, with postmentum and postoccipital margin dark brown.

Dorsal surface of head (Fig. 22): Frontoclypeus with straight anterior margin, labral sclerite sub-rectangular, lateral sclerite 1 and 2 fragmentary, 3 complete.

Antenna (Fig. 23): Total length 205-245 µm. Lengths of first to sixth segments (in µm): 98-113; 13-15; 30-50; 38-45; 8-13; 7.5; AR 0.8-0.9; first segment 3.7-4.0 times as long as basal width, ring organ located near the base 1/10. Antennal seta present at apical 1/5. Blade 115-150 µm long, extending beyond last flagellum, 1.2-1.3 times as long as flagellum. Lauterborn organ large, 15-20 µm long and 8-10 µm wide.

Labrum: SI plumose. Pecten epipharyngis consisting of 3 scales, lateral scales each with 5 teeth and median one with 4 teeth. Premandible 65-80 µm long, with 4 apical teeth, premandibular brush well developed (Fig. 24).

26

Mandible (Fig. 25): 115-125 µm long, with 1 apical, 1 dorsal and 2 distinct inner teeth. Mola area pale, with 2 spines. Seta subdentalis reaching the first inner tooth.

Mentum (Fig. 26): 80-90, 85 µm wide, with 2 median and 6 lateral teeth, first laterals distinctly small and low, depressed slightly to the second laterals. The median two teeth 14-18, 16 µm wide. Ventromentum subequal to the mentum in width, with 32-46 striae. Ventromental plate ratio (W/H) 1.6-1.8, the inter-plates distance very narrow, 4.5- 5.0 µm wide. Postmentum 120-140 µm long.

Body: Procercus 25-30 µm high, and 16- 20 µm wide, bearing 6-7 long together with 1-2 slender and short setae; the long one 760-1050 µm long, the slender short one 500-650 µm long. Supraanal setae weak, 50-60 µm long.

Material examined: 2 larvae, CHINA: Guangdong Province, Guangzhou City, Conghua District, Dongkeng Reservoir, 18-iii-2014, coll. HQ Tang.

Distribution: China (Guangdong Province)

Remarks: The larva may be those of Z. shidai sp. n. since they are collected from the same site; no other congeners were found at the site. This larva resembles Z. marmorata, but can be separated from the latter by the heavily sclerotized postmentum.