They are polyphagous in coniferous trees (mainly feeding on Pinus sylvestris, Pinus mugo and Pinus nigra, but also on Picea abies and Abies or Larix species).
Scots pine Pinus sylvestris and Larch Larix species (particularly plantations of L. decidua)
The larvae feed on a wide range of plants, including various broadleaved and coniferous trees and ferns, for instance Eucalyptus, Quercus, Acacia, Larix, Picea, Pinus and Pseudotsuga species.
Wild Agarikon is only found in old-growth forests, and grows on conifers, particularly Douglas-fir (Pseudotsuga) and larch (Larix).
The heavy forested mountains sustain many protected species of plants, such as yew (Taxus baccata), larch (Larix decidua), Swiss pine (Pinus cembra), edelweiss (Leontopodium alpinum); and animals, such as lynx (Lynx lynx), chamois (Rupicapra rupicapra), alpine marmot (Marmota marmota), golden eagle (Aquila chrysaetos), and capercaillie (Tetrao urogallus).
Caterpillars of Declana from New Zealand, also tentatively placed in the Nacophorini, have been found on Myrtaceae (eucalyptus, Kunzea and Leptospermum), Pinaceae – larches (Larix), pines (Pinus, notably Monterey Pine, P. radiata) and Coast Douglas-fir (Pseudotsuga menziesii) –, and southern beeches (Nothofagaceae).
The larvae feed on the leaves of various deciduous trees and shrubs, including Corylus, Fraxinus, Prunus, Quercus, Rubus, Swida sanguinea, Betula, Fagus, Larix, Pinus, Rhamnus frangula, Thelycrania sanguinea and Vaccinium.
The trees, however, he identified as more likely to represent larches (larices, singular larix), from which he derives the name Lariscolus ("young larch"), hence embodying the sisters of Phaëton transformed to larches.
The Scottish Crossbill breeds in the native Scots pine (Pinus sylvestris), Caledonian forests of the Scottish Highlands, but (perhaps surprisingly), often also in forestry plantations of exotic conifers, notably Larch (Larix decidua and L. kaempferi) and Lodgepole pine (Pinus contorta).