Tyloperla illiesi, sp. n. (Figs. 7-10)

Material. Holotype ♂ and 8 ♂ paratypes from Vietnam, Lao Cai, Sapa, large waterfall on road from Sapa to Lai Chau, 8 May 1995, D. Currie, B. Hubley, J. Swann, ROM 956022 (Holotype ROM, paratypes ROM, IEBR, BPS).

Adult habitus. Triocellate. Head with dark brown ocellar patch expanded around front of ocelli and inner margins of callosities and extending to M-line (Fig. 7); lappets brown, occiput dusky brown. Pronotum brown with extensive matrix of rugosities. Wings pale brown, veins brown. Femora with narrow brown apical band; tibiae yellow brown but slightly darker at knee and at apex.

Male. Forewing length 16-17 mm. Hair brushes on abdominal sterna 5-7 and on thoracic mesosternum. Abdominal tergum 7 with a small patch of sensilla basiconica. Tergum 8 with a small rounded and raised lobe covered with sensilla basiconica. Membranous field of tergum 9 with a mesal patch of sensilla basiconica set on a low mound (Fig. 8). Hemitergal processes acute, rather wide at base and curved outward at tip; basal cushion about a third as long as inner length of process; process in lateral aspect hooked slightly downward at tip (Fig. 9). Aedeagal sac trilobed; mesal lobe long, sharply curved and armed from bases of lateral lobes with small triangular spines; apical third of mesal lobe offset by an indistinct groove; lateral lobes small and covered almost entirely with spines (Fig. 10). Tube with a pair of small dorsoapical lobes.

Female. Unknown.

Larva. Unknown.

Diagnosis. This species is closely related to T. schmidi Stark & Sivec from Assam, but differs in the shape of the hemitergal processes (Stark & Sivec 1991). In that species the processes are less acute apically and not as wide at the base. In addition, the aedeagal sac armature is partitioned into two patches in T. schmidi and that species lacks a subapical groove on the aedeagal sac.

Etymology. We are pleased to propose this species in honor of the late Professor Joachim Illies in the initial volume of Illiesia.