Allohelea hamata Li &Wu, 2025

Lou, Jiawen, Wu, Xiaoxiang, Lin, Xiaodan & Li, Jiahui, 2025, Three new species of inflativena group of Allohelea Kieffer (Diptera: Ceratopogonidae) from Hainan Island, Zootaxa 5647 (6), pp. 558-570 : 560-563

Allohelea hamata Li &Wu , sp. nov.

Figs 1 (A–B), 2(A–B), 3, 4

Diagnosis. This species can be distinguished from all other species in the inflativena group by the following characters: wing with 3 anterior dark spots; hind femur dark brown with narrow subapical pale band; males with each paramere bifurcate with straight laterally-directed projections distally; females with functional spermathecae unequal in size.

Description. Female. ( Fig. 1A ) Habitus 1.81–1.95 (1.88, n=6) mm in length, body dark brown. Head brown, P/H 0.51–0.56 (0.53, n=4). Eyes contiguous, bare. Antenna brown with scape and pedicel dark brown, flagellum length 0.63–0.69 (0.66, n=5) mm, flagellomeres 9–13 significantly prolonged, AR 1.11–1.16 (1.14, n=5). Three bristles present on the inner side of antennal sclerite. Palpus light brown with the 5 th segment slightly darker; the 3 rd segment 40–48 (44, n=4) μm long, PR 2.27–2.14 (2.11, n=4), with a round sensory pit on the proximal half. Mandible with 9–11 teeth. Thorax dark brown, except for scutellum lighter laterally. Scutellum with 4 large bristles along the posterior margin. Wings ( Fig. 2A ) with 3 anterior dark spots and posterior irregular spots, a bluish brown spot present at apex of vein M 1, a light bluish brown foggy spot cover at vein A subapically, blisterlike swelling near base of vein M light brown; macrotrichia sparse, present along costal vein. Wing length 1.07–1.09 (1.08, n=4) mm, width 0.41–0.43 (0.42, n=4) mm, CR 0.80–0.82 (0.81, n=4). Halter pale. Legs ( Fig. 3D–F ) with coxae dark brown; fore- and midtrochanters brown, hind trochanter dark brown; fore- and midlegs with femora and tibiae largely brown except for darker apices of femora and pale knees; hind femur and hind tibia dark brown except for subapical pale band on femur, knee dark; all tarsi yellowish white. Hind tibia strongly thickened, the thickest point about 3 times as broad as the thickest point of midtibia. Tarsal spines: foretarsomere Ⅰ with 1 basal, 1 apical, II 1 apical, III 1 apical, IV 0 apical; midtarsomere Ⅰ with 10–12 spines, II 2 apical, III 2 apical, IV 0 apical; hind tarsomere ( Fig. 3B ) Ⅰ with 1 basal tiny, 1 apical spine; II 1 apical, III 1 apical, IV 0 apical spines, 2 ventral bristles. Hind tibial comb with 8 spines. TR 1 1.93–2.24 (2.08, n=4), TR 2 2.48–2.70 (2.60, n=4), TR 3 1.97–2.01 (1.99, n=4). Fore- and midclaws divided, equal sized, with small inner tooth and outer tooth, hind claws single, long, with a stout basal tooth. Abdomen ( Fig. 3A ) brown. Posterior margin of sternite 8 shallowly concave. Two functional spermathecae unequal in size, slightly longer than wide, with short neck, measuring 102–115 (109, n=4) μm by 73–88 (81, n=4) μm and 81–87 (84, n=4) μm by 67–72 (70, n=4) μm; small vestigial spermatheca present.

Male ( Fig. 1B ). Habitus 1.72–2.06 (1.89, n=2) mm in length. Generally similar to female, differs as follows: antenna flagellomeres 1–10 lighter colored than females, with yellowish-brown plumose hairs near the base; flagellomeres 11–13 obviously prolonged. Wing ( Fig. 2B ) length 0.99–1.04 (1.01, n=2) mm, width 0.32–0.34 (0.33, n=2) mm, CR 0.73–0.77 (0.75, n=2); three anterior dark spots similar but distal two much smaller than in females. Foretarsomere Ⅰ without or just with single spine at middle; hind tarsomere ( Fig. 3C ) II with 2 apical, III 0 apical spines, IV without ventral bristles. Genitalia as in Fig. 4A . Sternite 9 ( Fig. 4B ) wide at base, tapering towards posterior margin. Tergite 9 broad at base, tapering posteriorly, posterior margin truncate medially, with two well-developed apicolateral projections emerging from deep submedial concavities. Gonocoxite slightly thickened at base. Gonostylus is almost straight, about 0.8 times as long as gonocoxite, apex blunt. Aedeagus ( Fig. 4C ) broad at base, tapering, bifurcate distally with pointed apices, with one lateral projection on each outer margin. Parameres ( Fig. 4D ) connected at base, separating about 1/3 from base, basal arms short, each apex bent laterally at nearly 90°.

Type materials. Holotype male. CHINA • Hainan Island: Changjiang County, Qicha town , Bawangling National Nature Reserve : a Jungle next to water pipeline, alt. 506 m, 19°5.03'N, 109°7.02'E, 21.Ⅴ.2021, Xiaoxiang Wu leg., by light trap, cer1148-2.

Paratypes (3 males, 6 females). CHINA • Hainan Island : 2 females, 3 males, with same data as the holotype, cer1148, cer1148-1, cer1146, cer1148-3, cer1148-4 ; 1 female, Qiongzhong County, Limushan National Forest Park, 1.37 km northwest of Xue’ershanfang hotel, alt. 685 m, 19°10.03'N, 109°43.08'E, 20.XI.2020, Xiaoxiang Wu, Bin Deng & Zehua He leg., by light trap, cer1113 ; 3 females, Changjiang County, Bawangling National Nature Reserve, Badao board, alt. 533.7 m, 19°5.03'N, 109°7.02'E, 30. VI. 2024, Jiawen Lou, Zixuan Yang & Shiya Zheng leg., by light trap, cer2800-3, cer2800-1, cer2800-2 .

Etymology. The name hamata refers to the hook shaped lateral projections of the parameres.

Remarks. This new species closely resembles A. annulata Yu & Yan , and A. forceps Li & Wu , sp. nov. in colorations of wings and legs. The male of A. hamata can be distinguished from the latter two species by its bifurcate aedeagus with one lateral projection on each outer margin and parameres with apices nearly bent laterally at nearly 90°, whereas aedeagus of A. annulata is not separated apically and with no laterally projection, and apices of parameres of A. forceps strongly curved. For females, A. hamata can be distinguished from A. forceps by its unequal and subrounded spermathecae not swollen near neck, and differ from A. annulata by its strongly thickened hind tibiae.

All specimens of A. hamata were collected from the rainforest of Hainan Island at altitudes of 506–685 m.

Figures

FIGURE 1. Habitus of the three new species A, B Allohelea hamata Li & Wu, sp. nov. C, D Allohelea forceps Li & Wu, sp. nov. E, F Allohelea lurida Li & Wu, sp. nov. (A, C, E for female; B, D, F for male).

FIGURE 2. Wings of the three new species A, B Allohelea hamata Li & Wu, sp. nov. C, D Allohelea forceps Li & Wu, sp. nov. E, F Allohelea lurida Li & Wu, sp. nov. (A, C, E for female; B, D, F for male).

FIGURE 3. Allohelea hamata Li & Wu, sp. nov. A Spermathecae B, C Hind tarsi D Foreleg E Midleg F Hind leg (A, B, D–F for female; C for male).

FIGURE 4. Allohelea hamata Li & Wu, sp. nov. A male genitalia, ventral view B male genitalia with parameres and aedeagus removed, ventral view C aedeagus, ventral view D parameres, ventral view.