The larvae feed on "Picea glauca" and "Picea mariana". Red spruce ("Picea rubens") has arisen from an isolated population of black spruce ("Picea mariana"). Black spruce ("Picea mariana") is usually tamarack's main associate in mixed stands on all sites. Black spruce ("Picea mariana"), lodgepole pine and trembling aspen ("Populus tremuloides") are relatively minor associates. This is the westernmost location for the range of Black Spruce, "Picea mariana".