The Australian species of the genus Trigonopterus Fauvel are revised. Eight previously recognized species are redescribed and 24 additional new species are described: T. allaetus Riedel, sp. n., T. athertonensis Riedel, sp. n., T. australinasutus Riedel, sp. n., T. australis Riedel, sp. n., T. bisignatus Riedel, sp. n., T. bisinuatus Riedel, sp. n., T. boolbunensis Riedel, sp. n., T. cooktownensis Riedel, sp. n., T. daintreensis Riedel, sp. n., T. deplanatus Riedel, sp. n., T. finniganensis Riedel, sp. n., T. fraterculus Riedel, sp. n., T. garradungensis Riedel, sp. n., T. hasenpuschi Riedel, sp. n., T. hartleyensis Riedel, sp. n., T. kurandensis Riedel, sp. n., T. lewisensis Riedel, sp. n., T. montanus Riedel, sp. n., T. monteithi Riedel, sp. n., T. mossmanensis Riedel, sp. n., T. oberprieleri Riedel, sp. n., T. robertsi Riedel, sp. n., T. terraereginae Riedel, sp. n., T. yorkensis Riedel, sp. n.. All new species are authored by the taxonomist-in-charge, Alexander Riedel. Lectotypes are designated for the following names: Idotasia aequalis Pascoe, I. albidosparsa Lea, I. evanida Pascoe, I. laeta Lea, I. rostralis Lea, I. sculptirostris Lea, I. squamosa Lea. A new combination of the name Idotasia striatipennis Lea is proposed: Trigonopterus striatipennis (Lea), comb. n.. A key to the species is provided. Australian Trigonopterus occur in coastal Queensland, narrowly crossing into New South Wales. The southern parts of the range are inhabited by species found on foliage. A rich fauna of 19 edaphic species inhabiting the leaf litter of tropical forests is reported for the first time from the Australian Wet Tropics.
