Apatidelia acuminata Leng & Yang, 1998

Xie, Yue, Wang, Beixin & Sun, Changhai, 2017, Associations and a new species of the genus Apatidelia (Trichoptera, Apataniidae) from China, European Journal of Taxonomy 333, pp. 1-20 : 8-13

Apatidelia acuminata Leng & Yang, 1998

Figs 6–13 , Table 3

Apatidelia acuminata Leng & Yang, 1998: 26 , fig. 8 (males and females, deposited in NJAU).

Material examined

Holotype

CHINA: ♂, Mt. Longwang , Anji County, Zhejiang Province, alt. 360–490 m, 16–20 Oct. 1995, Beixin Wang leg. ( NJAU).

Other material

CHINA: 14 ♂♂, 13 ♀♀, same collection data as holotype; 1 ♂, 1 ♀, Mt. Dashan, Gaohong Town, Lin’an, Zhejiang Province, 119.62° E, 30.39° N, alt. 507 m, 11 May 2015, Jihua Xu, Yue Xie, Xiangjuan Wu, Lei Zhang and Zhen Liu leg.; 94 larvae, Huangjiawan, Xing Town, Huzhou, Zhejiang Province, 119.88° E, 30.77° N, alt. 64 m., 12 May 2015, Jihua Xu, Siwen He and Shuzhao Gao leg. (NJAU).

Description

Male ( Fig. 6 )

BODY LENGTH. 6.0 mm. Length of fore wing 7.0 mm.

BODY. Head black; eyes grey, ocelli white; cephalic setal warts white; vertexal medioantennal compact setal warts irregular, length equal to width; vertexal lateroantennal compact setal warts widely separated, length greater than width; vertexal lateroantennal fragmented setal warts small, numbers varying; occipital setal warts large, elliptical. Prothorax and pterothorax black, with setal warts white. Fore wings transparent, with numerous hairs; FI and FIII with a short petiolate; R 2 interconnect with R 3 after disc cell; base of FIII far away from joint vein r-m. Hind wings transparent and weak, each with 3 rod-like frenular setae at base of frenulum, each seta about 0.3 mm long. Sternum of segmental V with a short, finger-like lateral process on each side.

MALE GENITALIA. Segment IX annular; in lateral view ventral margin about 2 times as long as dorsal margin; preanal appendages short and rod-like, lateral margins each rough, with a small stout projection near base. External branches (ext. bra.) sickle-shaped on segment X, in lateral view tapering from base to apex ( Fig. 6A ); paired internal branches (int. bra.) thin and long, about as long as preanal appendages, with a pair of basal processes ( Fig. 6B ). Inferior appendages very elongate, basal segments of inferior appendages cylindrical in lateral view, covered with 5 strong bristles and some spine-like setae; distal segments of inferior appendages each knife-like, 3 times as long as basal segments of inferior appendages, with setae on outer surfaces and densely bristled on distal half of inner surfaces ( Fig. 6C ). Aedeagus tubular, strongly narrowed in middle, with distal margins much broader than basal margins; apex of aedeagus expanded in lateral view, with a row of hairs at anterior margin. Paired parameres each divided in 2 branches at middle; dorsal branches straight with some hairs; ventral branches shorter than dorsal ones, slightly sclerotized, curved upwards ( Fig. 6 D–E).

Female ( Fig. 7 )

BODY LENGTH. 9.0 mm. Length of each fore wing 7.5 mm. Body yellowish brown. Abdominal sternum V normal, without a lateral process on each side.

FEMALE GENITALIA. Sternum of segment VIII with a short vulvar lobe, somewhat rectangular in lateral view ( Fig. 7A ) and triangular in ventral view ( Fig. 7C ). Segment IX slightly sclerotized, smooth; posterior lobe of IX with apex shallowly incised mesally, subapically with 2 rectangular sclerites; lateral lobes of IX developed, subrectangular in lateral view and in ventral view; low. lob IX in lateral view arc-shaped, in ventral view slightly incised. Segment X visible in lateral and ventral views, slightly sclerotized, roof-shaped in lateral view, rectangular in ventral view. Processus spermathcae triangular in ventral and lateral view, paired spermathecal sclerites hook-like, connected by an arc-shaped sclerite subapically ( Fig. 7B ).

Final instar larva ( Figs 8–13 )

MEASUREMENTS. Body length 5.0–7.0 mm ( Fig. 13 A–C); maximum head width 0.7 mm.

HEAD. Head capsule oval in dorsal view ( Fig. 9 A–B), distinctly granulated with dense spinules. Overall coloration varying among individuals, from yellowish brown to dark brown, with dark brown stripes along dorsal ecdysial lines, and a transverse dark brown stripe near frontoclypeal corners; in some individuals with a transverse dark brown stripe at #14 seta; parietal with a dark brown band along lower margin on each side; along posterior margin and foramen occcipitale with dark brown stripes, some individuals with subtriangular spots at postgena ( Fig. 9C ). Eyes each oval, black, with a paler ring. Frontoclypeal apotome somewhat omega-shaped, with anterior margin straight. Antenna lies halfway between eye and anterior head margin, cylindrical, with a dark brown ring ( Fig. 9C ). Ventral apotome brown, posterior margin black, somewhat triangular, length larger than width. Ventral ecdysial line (0.195 mm) less than 25% of apotome length (0.050 mm). Labrum brown, with anterior margin straight or slightly concave, and a setal brush at each anterolateral corner. Mandible scraper black, in lateral view triangular, smooth, with a long lateral seta at end of basal third; only right mandible with stiff hairs at middle of inner margin ( Fig. 9D ). Cardo sub-rectangular, black.

THORAX. Pronotum rectangular, light brown to dark brown, varying among individuals, but posterior ridge always black; covered with white fine hairs and also 20–34 strong setae ( Fig. 10A ). Mid-dorsal ecdysial line twisted; in lateral view trapezoidal, each side with a black area just above each epimeron. Propleura small: each episternum elongate rectangular, and epimeron rounded, with only one central seta; each trochantin triangular, with sharp apex ( Fig. 10D ). Prosternal horn present. Mesonotum consists of 2 brown sclerites, their anterior, lateral margins strongly sclerotized, posterior margin paler ( Fig. 10B ). Setae scattered over mesonotal surface; each sclerite with about 20–30 setae. Mesopleura larger than propleura; each episternum triangular and sclerotized, with about 12–20 setae; each epimeron consists of a triangular sclerite with 11 setae and a membranous area covered with spinules. Metanotum membranous ( Fig. 10C ), paired sa 1 combined into a large trapezoidal area, with a row of 12–20 setae; sa 2 with a long black seta and 2 short setae; each sa 3 sclerotized, with about 9–12 setae. Metapleura equal to mesopleura in size ( Fig. 10E ), each episternum triangular and sclerotized, with about 17–20 setae, each epimeron consists of a membranous upper portion and a lower sclerotized portion with about 14–21 setae.

LEGS. Yellowish to light brown ( Fig. 11 A–C). Fore legs shorter and smaller than mid- and hind legs. Coxae cylindrical, with middle portion slightly bulging, basal and apical margins slightly edged. Trochanters triangular and 2-segmented, basal segment triangular and shorter than triangular apical segment; trochanteral brush present in fore legs, with about 7–10 hairs. Femora as long as coxae, cylindrical, upper and lower margins with hairs. Each tibia and tarsus slender. Tarsus claw curved upwards, with sharp apex, basal seta present.

ABDOMEN. Segment I with 1 fleshy hump dorsally and ventrally and 2 lateral fleshy humps ( Fig. 12 A–C); setal areas sa 1 distinctly separated by dorsal hump, each with about 8 setae; sa 2 absent; sa 3 with 2 setae; on abdominal sternum I sa 1 fused, creating continuous band of more than 30 setae, sa 3 with 1 seta. Dorsal surface of segments II–VII each with a pair of setae laterally. Venter of segments I–IX each with a pair of setae separated by chloride epithelia. Dorsum of segment VIII with 4–6 setae. Dorsum of segment IX with a median brown arc-shaped sclerite ( Fig. 12D ); posterior margin of dorsal sclerite with more than 30 setae; dorsum each with a seta separated by sclerite ( Table 3 ). Lateral sclerites of segment X rectangular in dorsal view, with 8–10 hairs, and 5 spines near posterior margin; ventral sole plate triangular; anal claws brown, without accessory hook. Lateral fringe from mid-segment II to VII. Chloride epithelia present on segment II–VII, those of segment III largest, those of segment IV second largest and others almost equal in size.

CASE. Cases of 5 th instar larvae 5.5–7.5 mm long (n =7), slightly dorsoventrally curved, tapering posteriorly, consisting of coarse mineral fragments, sometimes mixed with much larger particles which are mostly attached laterally ( Fig. 13D ).

Distribution

China (Zhejiang).

Figures

Fig. 6. Male genitalia of Apatidelia acuminata Leng & Yang, 1998. A. Lateral view. B. Dorsal view. C. Ventral view. Aedeagus. D. Dorsal view. E. Lateral view. Scale bar = 0.5 mm refers to all figures.

Fig. 7. Female genitalia of Apatidelia acuminata Leng & Yang, 1998. A. Lateral view. B. Dorsal view. C. Ventral view. Scale bar = 0.5 mm.

Fig. 8. Head setae of Apatidelia acuminata Leng & Yang, 1998, larva. A. Dorsal view. B. Ventral view. Scale bar = 0.5 mm.

Fig. 9. Head of Apatidelia acuminata Leng & Yang, 1998, larva. A. Dorsal view. B. Ventral view. C. Lateral view. D. Right mandible (lateral view). Scale bars: A–C = 0.5 mm; D = 0.25 mm.

Fig. 10. Thorax of Apatidelia acuminata Leng & Yang, 1998, larva. A. Pronotum (dorsal view). B. Mesonotum (dorsal view). C. Metanotum (dorsal view). D. Foretrochantin (lateral view). E. Mesopleura (lateral view). Scale bar = 0.5 mm.

Fig. 11. Legs of Apatidelia acuminata Leng & Yang, 1998, larva. A. Foreleg (posterior face). B. Midleg (posterior face). C. Hind leg (posterior face). Scale bar = 0.5 mm.

Fig. 12. Abdomen of Apatidelia acuminata Leng & Yang, 1998, larva. A–C. Segment I. A. Dorsal view. B. Ventral view. C. Lateral view. D. Segments IX–X and anal claw (dorsal view). Scale bar = 0.5 mm.

Fig. 13. Habitus of Apatidelia acuminata Leng & Yang, 1998, larva. A. Dorsal view. B. Ventral view. C. Lateral view. D. Case (ventral view). Scale bars = 1.0 mm.