Dolophilodes bellatula Sun & Malicky 2002

Hu, Yan-Li, Tsring, Samten, Wang, Bei-Xin & Sun, Chang-Hai, 2020, Descriptions of larvae of three Philopotamidae species from China (Insecta, Trichoptera), Zootaxa 4731 (4), pp. 509-521 : 513-515

Dolophilodes bellatula Sun & Malicky 2002

( Figs 4 A–5F)

Description. Larvae (5th instar). Body length 11–13 mm (n = 5), membranous body in alcohol white with head and pronotum yellowish brown ( Fig. 4A ).

Head. Head capsule ( Fig. 4B ) oblong in dorsal view, length about 1.5 times width, with smooth surface; yellowish brown, with black spot mesally on each posterolateral margin. Anterior margin of frontoclypeal apotome ( Fig. 4C ) extending forward in symmetrical arc, each anterolateral margin with 3 setae, seta no.1 strongest; seta no. 4 located near anterolateral angle, setae no. 5 located at level of tentorial pits. In lateral view ( Fig. 4D ), subrectangular, smooth, with posterior margin having V-shaped notch; setae no.13 short and small, situated about midlength on genae; lower margin of genal region with distinct stridulating ridges, indiscernible in ventral view. In ventral view ( Fig. 4E ) posterior margin incised, V-shaped, paired setae no.18 each located at midlength of genae; anterior ventral apotome triangular, its anterior margin straight with anterolateral angles rounded and slightly produced anterad; without posterior transverse sulcus. Eyes ( Fig. 4D ) oval, black, surrounded by yellow halo. Antennae small, each bearing of two rod-like spines subequal in length, located near base of its mandible. Labrum ( Fig. 4F ) white, membranous, T-shaped; transverse distal portion rod-like, transparent, with 4 discernable pairs of setae behind anterior margin; anterior margin densely setose and notched mesally; anterolateral margins each having tuft of bristles curved antirad; labral stalk constricted basally.

Mandibles ( Figs. 4G 1 , 4G 2 ) brown, slightly darker than head, each with two bristles situated about midlength of arched outer margin; inner margins each with broad mesal tooth near midlength, serrate margin about 3/4 length, small tooth in subapical recess; distal tooth of left mandible slightly larger than right one. Maxillae and labium fused ( Figs. 4E, 4H ). Maxillae each with cardo somewhat pentagonal, its inner mesal angle covered by submentum; stipes membranous, with oblique blade-shaped sclerite issuing from anterior margin of cardo and extending to mentum of labium; fused galea and lacinia in ventral view triangular, their mesal margin heavily setose, lacinia with apex having two spine-like bristles; palpifer large, subrectangular in ventral view, with basal margin sinuate; maxillary palp 4-segmented, with first segment shortest, second slightly longer, third and fourth segments of same length, each equalling length of first and second segments combined, fourth segment with sensillae.

Submentum of labium trapezoidal, with each anterolateral angel having strong bristle; mentum elliptical, with anterior margin irregularly convex anteriorly; labial part proper with apical margin rounded, setose; palpiger barshaped and slightly sinuate, labial palpi each 2-segmented.

Thorax. Pronotum ( Fig. 5A ) rectangular in dorsal view, length equal to width, constricted posteriorly, sclerotized, of same colour as head, with broad black posterior border extending anterad on lateral margins to anterior edges of proepisterna ( Fig. 5B ). Anterolateral angles each with several setae, mid-posterior area with transverse row of 10 relatively small setae. Foretrochantins ( Fig. 5B ) fingerlike, each with tip blunt and rounded, slightly bent downwards. Meso- and metanota ( Fig. 4A ) completely membranous, white.

Proepisterna black, triangular in lateral view, each with anterodorsal and anteroventral angles pointed; proepimeron semi-circular, with upper margin black, other portions brown. Meso- and metaepisterna dark brown, triangular, each with anterodorsal angle slightly curved upwards, meso- and metepimera dark brown, somewhat elliptical vertically.

Legs. Legs ( Figs. 5C1–5C3 ) yellowish brown, sclerotized and subequal. Forelegs slightly stouter and darker than mid- and hind legs; each with coxa having long black bristles and small sclerotized basodorsal process bearing long black bristle; tarsus with row of short spine-like setae ventrally ( Fig. 5F ). Trochanter of each leg 2-segmented; femora, tibiae, and tarsi of all legs almost equally broad, with sparse spine-like setae on their surfaces; claws small but well developed, slightly curved downwards and each with conspicuous basal process and basal seta.

Abdomen. Abdominal segments I–IX white, with sparse short setae on their surfaces. Lateral fringe and tracheal gills absent; with 5 single apicodorsal anal papillae at end of segment IX in dorsal view ( Fig. 5D ). Anal prolegs ( Fig. 5E ) each with basal half unsclerotized, distal half sclerotized and of same colour as mid- and hind legs, each with one sub-basoventral seta and three much longer subapicodorsal setae. Anal claws ( Fig. 5E ) in lateral view each with base strong and sharp apex curved downwards at 90 degrees, with 4 small sub-basodorsal setae.

Materials examined. CHINA, Zhe -jiang Province, Lin -an, Tianmu Mountains: 1 larva, Shui-wu-li, 30.3550°N, 119.5958°E, Alt. 230 m, 12 Oct 2017; 57 larvae , Shui-wu-kou, 30.4008°N, 119.5944°E, Alt. 616.8 m,

12 Oct 2017; collected by Yan-li Hu, Yu Wang & Lang Peng. Lin -an: 1 male, Heng-du, 30.2951°N, 119.5687°E, Alt. 169 m, 21 Oct 2015; 1 male, Gao-hong Town , Da-shan, 30.3944°N, 119.6190°E, Alt. 507 m , 12 May 2015; collected by Ji-hua Xu. Anhui Province, Mount Huangshan , 2 males, Hou-shan, 29.7201°N, 118.3321°E, Alt. 120 m , collected by Ji-hua.

Distribution. China (Zhejiang, Anhui).

Figures

FIGURE 1. COI neighbor-joining diagram used to determine larva-male associations of Chinese Philopotamidae species. M. = male; L. = larva.

FIGURE 2. Chimarra sadayu Malicky 1993, larva. 2A, habitus, right lateral; 2B, head, dorsal; 2C, frontoclypeal apotome, dorsal; 2D, head, right lateral; 2E, head, ventral; 2F, labrum, dorsal; 2G1, left mandible, dorsal; 2G2, right mandible, dorsal; 2H, maxilla and labium, ventral. 1–18 = setae 1–18.

FIGURE 4. Dolophilodes bellatula Sun & Malicky 2002, larva. 4A, habitus, right lateral; 4B, head, dorsal; 4C, frontoclypeal apotome, dorsal; 4D, head, right lateral; 4E, head, ventral; 4F, labrum, dorsal; 4G1, left mandible, dorsal; 4G2, right mandible, dorsal; 4H, maxilla and labium, ventral. 1–18 = setae 1–18.

FIGURE 5. Dolophilodes bellatula Sun & Malicky 2002, larva. 5A, pronotum, dorsal; 5B, right side of pronotum, right foretrochantin, and right forecoxa, right dorsolateral; 5C1, right foreleg, posterolateral; 5C2, right midleg, posterolateral; 5C3, right hind leg, posterolateral; 5D, segment IX and prolegs, dorsal; 5E, left proleg, left lateral; 5F, terminal portion of tarsus and claw of right prothoracic leg, posterolateral.