coniferous forests, but the beetles were sometimes found in coniferous plantations. Larva feeds on rotten wood, and the adults drink juice, which protrudes from the trunks of linden, elm and other trees. In captivity, one female could drink up to of sugar syrup at once. Adults are active during the day; in the night they fly to the light sources. During the day, females fly more than males and therefore are encountered more frequently. Larvae develop in such trees as Japanese elm, Manchurian Ash, Tilia amurensis and Populus maximowiczii; they rarely occupy Mongolian oak, sawtooth oak, Siberian elm, Japanese elm, Betula costata, Carpinus laxiflora and Manchurian maple. Entomopathogenic fungus of the form Metarhizium anisopliae (Clavicipitaceae family) is deadly for a variety of insects, including the adult Callipogon relictus. Reproduction Females reach a length of , and the males are long. Females emit a special secretion to attract a partner. Mating occurs on the tree which serves as a feeding ground for larvae, below the place where the female will lay eggs; copulation lasts up to an hour. After mating the male does not leave female. Instead, he places front legs on the elytra of the female and they together climb the tree up to where the female will lay eggs. Eggs are laid by one or in groups on the bark of trees with a trunk diameter of . Over a lifetime (adult beetles live up to a month), a female can produce up to 28 eggs. After the female has laid eggs, the couple crawls down tree and dies on the ground. Newborn larvae dig under the bark making corridors up to long and wide. They then delve into wood to a depth of creating a network of tunnels there. One tree is re-populated several times and therefore usually contains larvae of different ages; only completely dried out trees are suitable for larva development. If a dry tree branch breaks from the tree with the larvae inside, the larvae stays inside the branch, but produces smaller adults than usual. Larvae live through 4–6 winters. After the last overwintering, they make large cradles () oriented perpendicular to the trunk, separated from the tree surface by about . Then the larva turns in the cradle with its head toward the trunk surface and pupates. Pupation occurs in June–July during 20–35 days and the pupa growth up to long. Females exit cradles