1	Aedeagus: laterophyses reaching apices of conjoint dorsal plate of parameres	2
–	Aedeagus: laterophyses reduced, not reaching apices of conjoint dorsal plate of parameres	4
2	Antennae, mid and hind legs uniformly black; aedeagus (Wittmer 1997: fig. 104): laterophyses without processes on both sides	T. minor Wittmer, 1997
–	Antennae and legs mixed yellow and black; aedeagus: laterophyses with a narrow process each side	3
3	Aedeagus (Wittmer 1983b: fig. 2): conjoint dorsal plate of parameres triangularly emarginate in middle of apical edge in dorsal view; female abdominal sternite VIII (Wittmer 1983b: fig. 62) with lateral protuberances of posterior edge nearly as wide as distance between them	T. subcaeruleus (Pic, 1911)
–	Aedeagus (Wittmer 1983b: fig. 3a): conjoint dorsal plate of parameres rectangularly emarginate in middle of apical edge in dorsal view; female abdominal sternite VIII (Fig. 9D) with lateral protuberances of posterior edge about half as wide as distance between them	T. crassimargo Champion, 1926
4	Aedeagus: ventral process of each paramere hooked at apex in lateral view	5
–	Aedeagus: ventral process of each paramere not hooked at apex	9
5	Aedeagus: ventral process of each paramere expanded and obtusely hooked dorsally at apex (e.g. Fig. 5C)	6
–	Aedeagus: ventral process of each paramere narrowed and acutely hooked ventrally at apex	8
6	Elytra dark green or blue, strongly metallic	T. nepalensis (Hope, 1831)
–	Elytra purple-black, weakly metallic	7
7	Body longer than 16.0 mm; female internal genitalia (Fig. 6D) with diverticulum narrowed apically	T. crassipes Pic, 1929
–	Body 13.0–15.0 mm in length; female internal genitalia (Fig. 7C) with diverticulum expanded apically	T. masatakai Okushima, 2003
8	Aedeagus (Fig. 6B): ventral process of each paramere triangularly protuberant apicolaterally in dorsal view; female abdominal sternite VIII (Fig. 9B) with each protuberance narrower than the distance between it and apicolateral angle	T. cavipennis (Fairmaire, 1897)
–	Aedeagus (Wittmer 1983b: fig. 5): ventral process of each paramere normal, not protuberant in dorsal view; female abdominal sternite VIII (Fig. 9J) with each protuberance wider than the distance between it and apicolateral angle	T. uncinatus Wittmer, 1983
9	Elytra no more than 1.5 times as long as maximal width; aedeagus (Wittmer 1983b: fig. 4): ventral process of each paramere with apex slightly bent inwards in ventral view, nearly as long as conjoint dorsal plate in lateral view	T. laboissierei Pic, 1929
–	Elytra about twice as long as maximal width; aedeagus: ventral process of each paramere with apex unlike above, not bent inwards in ventral view, longer than conjoint dorsal plate in lateral view	10
10	Aedeagus (Wittmer 1983a: fig. 47): ventral process of each paramere abruptly narrowed at apex in ventral view; female abdominal sternite VIII (Fig. 9I) with acute apicolateral angles	T. sauteri (Pic, 1912)
–	Aedeagus (Fig. 6C): ventral process of each paramere expanded at apex in ventral view; female abdominal sternite VIII with rounded apicolateral angles	11
11	Tibiae mixed yellow and black; aedeagus (Wittmer 1983b: fig. 1): ventral process of each paramere narrowed apically in ventral view, conjoint dorsal plate widely emarginate medially at apical edge in dorsal view	T. coelestis (Gorham, 1889)
–	Tibiae uniformly black or yellow; aedeagus: ventral process of each paramere almost even in width in ventral view, conjoint dorsal plate narrowly emarginate medially at apical edge in dorsal view	12
12	Femora mixed yellow and black, tibiae black; female abdominal sternite VIII (Fig. 9F) with protuberances of posterior edge not reaching apices of apicolateral angles in ventral view	T. impressipennis (Fairmaire, 1886)
–	Femora and tibiae uniformly yellow; female abdominal sternite VIII (Fig. 9A) with protuberances of posterior edge exceeding apices of apicolateral angles in ventral view	T. bicoloricornis Wittmer, 1983