Key to species of Trichoceridae known from Korea

1. Relatively small in size, wing 4–6 mm long, D-cell pentagonal, first tarsal segment very short, only about 1/10 of the second segment............................................ Subfamily Paracladurinae, Paracladura rasnitsyni Krzemińska

- Larger in size, wings mostly 7–9 mm long; D-cell more triangular, first tarsal segment long, up to twice as long as the second segment........................................................................ Subfamily Trichocerinae, 2

2. Wing patterned, dark areas over the base of vein Rs, cross-veins r-m, r-r, around D-cell, over the radial vein area and medial veins, at the end of A2 (Fig. 1–6)......................................... T. (S.) maculipennis punctipennis Brunetti

- Wing unpatterned (Fig. 7), or at most with a spot over cross-vein r-m ............................................ 3

3. Gonostylus with one or more conspicuous processes at mid-length.............................................. 4

- Gonostylus without processes at mid-length; at most with an inconspicuous basal tubercle........................... 6

4. Gonostylus with one triangular, acute process at mid-length; apex of gonostylus hooked (Fig. 20)..................................................................................................... T. (T.) sakaguchii Alexander

- Gonostylus with two or three processes....................................................................5

5. Gonostylus with one long, straight process at base and one smaller process closer to apex (Fig. 24)... T. (T.) sibirica Edwards

- Gonostylus with one long, slightly bent process at base and two processes at apex, forming a “V” shape (Fig. 25). Distal wing cells with macrotrichia............................................................ T. (T.) mirabilis Alexander

6. Pleuron with setae on both anepimeron and metepisternum (Fig. 23).................. T. (S.) sparsa Starý & Martinovský

- Pleuron bare or rarely with one or two setae either on anepimeron or metepisternum.................................7

7. Ventrobasal lobes of gonocoxites not fused, with a clear gap (i.e. gonocoxal bridge incomplete, Figs. 22, 23)............. 8

- Ventrobasal lobes of gonocoxites fused, forming a complete bridge (Figs. 17–21)...................................9

8. Ventrobasal lobes of gonocoxites rather narrow, forming a high arc (Fig. 22). Usually a clear spot is visible on r-m, tarsal claw only slightly shorter than the last tarsal segment...................................... T. (S.) regelationis (Linnaeus)

- Ventrobasal lobes wide, they form a rather low arc (Fig.26–27). Wings clear, tarsal claw equals half of the last tarsal segment (Fig. 29)........................................................................... T. (S.) latipons sp. nov.

9. Gonostylus longer than gonocoxite, slightly bent at mid-length, slightly sinuous, without basal tubercle (Fig. 19); one of the

largest species, wing length 8–9 mm ...................................................... T. (T.) major Edwards - Gonostylus approximately equal in length to gonocoxite, with tooth-like or smaller triangular tubercle at base.......... 10

10. Basal tubercle of gonostylus thin and acute, tooth-like (Fig. 18). Sternite IX with an outgrowth at median, directed toward the bridge (not clearly visible in all specimens)............................................. T. (T.) hiemalis (De Geer)

- Basal tubercle triangular and blunt (Fig. 17). Sternite IX lacking median outgrowth.................................................................... T. (T.) tuberculifera Alexander ( T. latilobata (Fig. 21) should key out here as well).