Thanasimus Formicarius - Life Cycle

Life Cycle

The adults overwinter at the base of conifers, rarely of deciduous trees . They emerge in the spring and fly to lower parts of trees to hunt bark beetles. Their common prey are pine bark beetles Tomicus piniperda and T. minor, and the spruce bark beetle, Ips typographus. Often they are seen waiting their prey on the bark of fallen pine or spruce trees. Both ant beetles and bark beetles are attracted to monoterpenes from the damaged areas of the fallen trees. Stacked wood is especially attractive due to the monoterpene volatiles. The ant beetles are also attracted to specific pheromone components of bark beetles therefore they often fall into bark beetle pheromone traps. The larvae enter the scolytid galleries and feed on the immature stages of the bark beetles. The larvae, grows very slowly (spends two years in the larval stage), and pupate, in the fall. In niches in the outer bark. Adults of T. formicarius live 4 to 10 months.

Males and females mate repeatedly, with different many partners throughout the season. Mating is short, and the copulation precedes a chase and a firm grasp of the female with the male mandibles on her pronotum.

The females lay eggs from April to June. Usually they produce 20 to 30 eggs that they lay in bark crevices and in the vicinity of the bark of pine trees running tunel of the bark beetle. The pink-colored larvae hatch after about a week and live under the bark, where they are predators of bark beetle larvae, eggs and pupae, but also feed on other insects living under the bark. In pursuit of their prey, they are also very quick and very skilled at moving the bark beetle corridors, where they can run backwards.

Before pupation, the larvae form an oval chamber which they line with mucus under the bark. The following spring the beetles emerge.