Distribution Southeastern Brazil, Atlantic forests
Systematics Monotypic. Member of the tergal lobe clade (Grehan, 2010).
Biology Eggs are deposited by the female at rest (and probably during flight as in other Hepialidae). Larval development is two or three years. Larvae observed in Eucalpyptus plantations (Briquelot, 1956) were found to excavate tunnesl mostly between 30 cm to 3 m from the ground at a point where vines come into contact with the eucalyptus trunk. The tunnel entrance is covered by a web of silk and wood fragments. The tunnel penetrates the host at an incline of about 45º and then turns vertically down in the heartwood to a length of 20 to 40 cm. In one case a larva was observed to feed entirely on the attached vine without penetrating the eucalyptus. Prior to pupation the larvae constructs a cover over the entrance of the tunnel. The pupal state lasts about two months.
Trichophassus giganteus is a timber pest and in eucalytus plantations 90% of trees with vines were attacked. The occurance of several tunneles in young trees could lead to windthrow and the tunnels provide access for other insects (Briquelot, 1956).
The name 'tarantula moth' has been given in reference to the tarantula-like appearance of the head and legs (Ferrari & Ferrari, 2011).