Apetaenus watsoni Hardy, 1962: 965 [Macquarie Island. Hurd Point; HT ♂, ANIC].— Womersley, 1937: 75 [as Apetaenus litoralis Eaton, citation, Macquarie Island].— Watson, 1967: 28 –29 [ecology].— Harrison, 1976: 127 [citation, Macquarie Island].— Mathis and Sasakawa, 1989: 667 [Australasian/Oceanian catalog].— Mathis and Munari, 1996: 8 [World catalog].— Davies et al., 1997: 456 –457 [citation, Macquarie Island, Bishop Island].
Distribution. Australasian/Oceanian: hitherto only known from Bishop Island and Macquarie Islands.
Material examined. Eight paratypes (4 ɗɗ 4 ΨΨ from Macquarie Island: Hurd Point, Nuggets Point, North Head) of this subspecies were examined from the collections of BMNH and ANIC—six specimens from the latter collection are now in the author’s collection (MCNV). All these paratypes are in rather good condition.
Habitat and microhabitats. A thalassobiont species with a marked preference for microdetritivorous, polysaprophagous and possibly coprophagous diet. It seems to be strictly associated as a polysaprophagous insect to sea bird nests and penguin colonies. It was recorded in the literature from the following microhabitats: on Colobanthus muscoides cushions, algae on coastal rocks, under rookery stones and rocks (Hardy, 1962; Watson, 1967); coastal rocks of the upper Porphyra zone amongst red, brown and green algae, rotting kelp, closely associated with areas around rookeries where there is plenty of rotting organic matter (Watson, 1967); on Puccinellia macquariensis on rocks close to the sea (Watson, 1967; Harrison, 1976); under loose rocks or in rock crevices, bare soil, bird nests (Davies et al., 1997). Some interesting ecological observations made by Watson (1967) are as follows:”These brachypterous flies [indeed they are strictly micropterous flies] are quite abundant throughout the year. They can be seen walking slowly over the algae or bare rock in the upper Porphyra zone; pairs in copulation are commonly seen throughout the year. Less frequently, flies can be found walking over pebbles on the beach, and in clusters on pieces of kelp and under stones and driftwood. In penguin rookeries they mass together under stones in the well manured mixture of mud and feathers. Here the immature stages lie in the wet mud; on the coastal rocks they are found entangled in the fine, filamentous green alga (Rhizoclonium sp.), amongst the fronds of Porphyra umbilicalis and in crevices of the rock. The pupae attach themselves to the rock or alga by a secretion”.