Tyloperla bimaculata, Li & Kong, 2020

Li, Weihai & Kong, Fanbin, 2020, A new species and new record of Tyloperla (Plecoptera: Perlidae) from China, Zootaxa 4728 (2), pp. 289-294 : 290

Tyloperla bimaculata sp. nov.

( Figs. 1–3 )

Male. Body length ca. 13.8 mm, forewing length ca. 17.2 mm, hindwing length ca. 15.0 mm. General color yellow brown. Triocellate, anterior ocellus smaller. Head slightly wider than pronotum, mostly pale, with a pair of small dark brown patches forward of posterior ocelli, the patch subequal to the size of one posterior ocellus; compound eyes dark; antennae brown. Pronotum mostly brown, anterior margin darker, with paired closely set longitudinal median strips and dense, distinct brown rugosities ( Fig. 1a ); wing membrane pale brown, veins brown; legs mostly yellowish brown, knees darker.

Terminalia . Posterior margin of tergum 7 with a small patch of sensilla basiconica. Tergum 8 with a large field of sparse sensilla basiconica, its posterior part sclerotized, with an upraised brown sclerite together with two triangular wings which generally seems like a butterfly, in lateral aspect this area appearing as a projecting cone. Membranous portion of tergum 9 anteriomedially with dense small sensilla on an elevated area better seen in lateral view. Hemitergal processes of tergum 10 grooved along inner surface, tip acute and slightly hooked in lateral view; basal callus rounded ( Figs. 1b & 1c ).

Aedeagus ( Figs. 1 d–1e, 2 & 3): Aedeagal tube with paired membranous, conical, dorsoapical lobes. Aedeagal sac trilobed: medial lobe abruptly curved medially, apical third offset by a shallow but distinct groove; basal band of spines and basal portion of apical spinous band interrupted into two patches ( Figs. 2b , 3b ), armature of apical third dark and stout; lateral lobes darkly pigmented, with densely clustered, stout spines ( Figs. 2a , 3a ).

Female. Unknown.

Type Material. Holotype: male, China: Guizhou, Suiyang County, Kuankuoshui National Nature Reserve , 300 m, 107°19.98 E, 28°24.03 N, 2010.VIII.13, Yan Li ( CAU).

Etymology. The specific epithet refers to the two stigmata of the head.

Distribution. China (Guizhou).

Remarks. The new species is closely related to T. illiesi originally described from Vietnam (also known from Yunnan Province of China as reported below) in the general characters of terminalia and aedeagus. However, the ocellar patch of T. illiesi is entire between posterior ocelli and much larger and extends to M-line, whereas the medially interrupted patch in the new species is much smaller and about as large as one posterior ocellus. Additionally, the spinous sclerite on tergum 8 in T. bimaculata sp. nov. is butterfly-like but that in T. illiesi is roughly rounded and tergum 7 in T. illiesi has no patch of sensilla basiconica as occurring in T. bimaculata . Finally, the basal band of spines and the basal portion of apical spinous band of the aedeagal sac in T. bimaculata sp. nov. are interrupted dorsally whereas those patches are entire in T. illiesi .

Figures

FIGURE 1. Tyloperla bimaculata sp. nov. (male). a. Head and pronotum, dorsal view. b. Terminalia, dorsal view. c. Terminalia, lateral view. d. Aedeagus, lateral view. e. Aedeagus, oblique lateral view.

FIGURE 2. Tyloperla bimaculata sp. nov. (details of male aedeagus). a. Aedeagal sac, lateral view. b. Aedeagal sac, dorsal view.

FIGURE 3. Tyloperla bimaculata sp. nov. (details of male aedeagus). a. Aedeagal sac, dorsolateral view. b. Dorsal curve of aedeagal sac, top view.