Key to the species of Trachylestes

1. Pronotum with anterior and posterior lobes except posterior margin uniformly coloured black (Fig. 3) (antennal segment 1 and femora contrastingly banded piceous and pale yellow).................................................. T. turneri

- Pronotum with anterior and posterior lobes not uniformly black, coloured with variable shades of pale and dark (e.g., Fig. 1)..................................................................................................... 2

2. Broad and robust insects, body less than three times as long as its maximum width (Fig. 12)..... T. queenslandensis sp. nov.

- Narrow and slender insects, body more than 3.5 times as long as its maximum width (e.g., Fig. 5)...................... 3

3. Pronotum with anterior lobe uniformly yellowish, posterior lobe fuscous except broad median yellowish area; abdomen in side view with piceous patches on connexival segments 4–7 (Fig. 2)....................................... T. aspericollis

- Pronotum with anterior and posterior lobes with shades of dark and light patches (Fig. 5); abdomen in side view with two sets of piceous or black patches on segments 4–7, one on connexiva and another one submarginal (Fig. 5)...................................................................................................... T. barrowensis sp. nov.