Cryptotendipes

Yan, Chuncai, Tang, Hongqu & Wang, Xinhua, 2005, A review of the genus Cryptotendipes Lenz (Diptera: Chironomidae) from China, Zootaxa 1086, pp. 1-24 : 17-19

Cryptotendipes sp. 4 ( Fig. 8 A–F)

Material examined: 4 larvae. CHINA, Fujian Province, Jianning County, Wuyi Mountain Natural Conservation, 25.IX.2002, leg. Z. Liu.

Fourth­instar larva

Total length 5.03–5.50, 5.32 mm, head capsule 300–330, 318 µm long, 280–310, 298 µm wide, cephalic index 0.88–0.97, 0.93.

Coloration ( Fig. 8 A): Larva in alcohol white with some yellow marks. Head capsule yellowish brown. Posterior occipital margin and gula dark brown.

Antenna ( Fig. 8 B): Total length 64–72, 68 µm long; 0.18–0.22, 0.20 times as long as head capsule and 0.53–0.56, 0.54 times as long as mandible. Antennal segment lengths (in µm): 38–40, 40; 13–15, 15; 2–3, 2; 4–5, 5; 4–5, 4. AR = 1.38–1.54, 1.45. Basal segment 14–16, 15 µm wide. Antennal blade 25–30, 28 µm long, reaching apex of fifth segment, accessory blade 18–20, 19 µm long, extending to apex of third segment. Ring organ located at 0.3 of basal segment, 12–16, 15 µm long from base. Style at apex of second segment, 4–5, 4 µm long, extending to third segment. Lauterborn organ absent.

Labrum ( Fig. 8 D): Both SI and SII slender, slightly broadened proximally. SI 25–28, 26 µm long and SII 38–42, 40 µm long. SIII simple; SIVA consists of 2 segments, basal segment 7.5 µm long, distal segment 6 µm long (n = 1). Chaetulae laterales 5 pairs, basal branch apparently simple, others distally serrated. Pecten epipharyngis a simple, distally trifid plate of variable length. Premandible with 2 pointed apical teeth, inner tooth broader, 1 blunt basal tooth slightly concave in middle. Premandible brush present. Anterior margin of frontal apotome ( Fig. 8 C) straight, S3 located in each corner. SL1 and SL2 fused into 1 sclerite, S1 at distal margin. SL3 present, other sclerites absent.

Mandible ( Fig. 8 E): Total length 115–130, 122 µm long, brown distally, pale basally, 2 inner teeth, third false teeth present on mola, apex of teeth slightly triangular, not as flat as typical. Seta subdentalis blade­like, relatively short, 20–24, 23 µm long, extending to apex of first inner tooth. Seta interna with 4 branches, first, second and fourth branches simple, distal part of third branch splits into 3 or 4 small slender branches.

Mentum ( Fig. 8 F): Total length 105–112, 109 µm. Median tooth trifid, lateral notch distinct, 30–33, 31 µm wide. Outer 3 lateral teeth fused into compound tooth, clearly set off. Ventromental plate 95–102, 99 µm wide (w), 35–37.5, 36 µm long (l). Separation between plates 50–56, 53 µm. VmPR (w/l): 2.53–2.91, 2.78; VmPSR (w/s): 1.70–2.01, 1.91; mentum ratio (VmP/M): 0.88–0.95, 0.91. Striae number 24–26. Seta submentum simple, distance between setae submenti 63–70, 66 µm. Postmentum 138–160, 145 µm long.

Abdomen: Posterior parapods 200–230, 220 µm long, 115–120, 118 µm wide, with 16 yellow simple claws. Procercus 15–20, 18 µm high, 20–25, 22 µm wide, procercus ratio 0.72–0.80, 0.75, with 8 anal seta, 400–455, 435 µm long. Supraanal seta 240–260, 252 µm long.

Remarks: The larva resembles that of C. nigronitens , based on the outline of the mentum. However, we have no associated adult specimens. Thus, we treat this larva as C. sp. 4.

Figures

FIGURE 8. Cryptotendipes sp. 4. Fourth­instar larva. A. Gula and posterior occipital margin. B. Antenna. C. Frontal apotome and labral sclerites. D. Labrum. E. Mandible. F. Mentum.