Troides helena is common in woodlands at low to high elevations (Alt. 30 - 2000m). Both sexes visit flowers.

Males are frequently observed coming to the streams to suck water during the dry season in North Laos
The taxon is highly variable in both sexes.

Troides aeacus is common in woodlands at low to high elevations (Alt. 200 - 2200m) and is occasionally seen in urban areas. Both sexes visit flowers.

Both species are protected under the CITES Annex II, even if they are very common.

Both species can be observed easily from March through October.