The general life cycle of clerids has been known to last anywhere from 35 days to more than 3 years, and is strongly dependent on the life cycle of their prey.
While the life cycle can vary in length between genus and species, temperature is also a major determinant in the length of time spent in each stage of development.
The warmer the temperature is, the quicker the lifecycle, and the cooler the temperature is the slower the lifecycle.
If temperatures dip below a threshold temperature for an extended period of time clerids and most other insects will have growth and developmental progress arrested.
Like all beetles, Cleridae follow a holometabolous life cycle: the egg hatches into a larva, which grows and feeds, changing its skin to form a pupa, and the pupa shedding its skin to emerge as an adult.
The larvae of the majority of the known species of Cleridae feed upon the eggs and young of wood-boring beetles, while the adults feed on the adult bark beetles.

Copulation takes place while the female feeds, because females need a large amount of food for egg development.
The female lays her eggs 36–72 hours after copulation.
The eggs are laid in between pieces of bark on wood-borer-infested trees or under stones in the soil.
She may lay 28–42 eggs at a time.
For the longer lifespaned species such as Thanasimus this occurs in late summer or early fall to give the larvae enough time for proper growth before having to overwinter.

When larvae hatch from their eggs, they are either red or yellow.
Their bodies have a slender and flat appearance with short legs due to their minimal movement.
The larvae are covered in hair and have two horn-type projections on the dorsal area of the last body segment.
Immediately after birth, they start searching for food close to where they hatched.
They feed on wood-borer insects on trees, or feed on their species' substrate or prey of choice.
Feeding is the main purpose of the larval stage to prepare for pupation.
Once their larval stage is complete the tree dwelling species make their way to the bottom of the tree to pupate.
The pupal stage can last from 6 weeks to one year depending on the need to overwinter, and how short the overall lifecycle is for a particular species.
A majority of clerid species pupate in earthen cells which are made from soil and certain enzymes secreted from their mouths.
The rest remain in pupal cells.
Adult beetles emerge from pupation and spend a variable time of their life maturing, and eventually oviposit.
Sexually mature adults or imagos of Thanasiumus overwinter inside the wood-borer-infested trees and oviposit during the spring.
The general life cycle of clerids has been known to last anywhere from 35 days to more than 3 years, and is strongly dependent on the life cycle of their prey. While the life cycle can vary in length between genus and species, temperature is also a major determinant in the length of time spent in each stage of development. The warmer the temperature is, the quicker the lifecycle, and the cooler the temperature is the slower the lifecycle. If temperatures dip below a threshold temperature for an extended period of time clerids and most other insects will have growth and developmental progress arrested. Like all beetles, Cleridae follow a holometabolous life cycle: the egg hatches into a larva, which grows and feeds, changing its skin to form a pupa, and the pupa shedding its skin to emerge as an adult. The larvae of the majority of the known species of Cleridae feed upon the eggs and young of wood-boring beetles, while the adults feed on the adult bark beetles.
Copulation takes place while the female feeds, because females need a large amount of food for egg development. The female lays her eggs 36–72 hours after copulation. The eggs are laid in between pieces of bark on wood-borer-infested trees or under stones in the soil. She may lay 28–42 eggs at a time. For the longer lifespaned species such as Thanasimus this occurs in late summer or early fall to give the larvae enough time for proper growth before having to overwinter.
When larvae hatch from their eggs, they are either red or yellow. Their bodies have a slender and flat appearance with short legs due to their minimal movement. The larvae are covered in hair and have two horn-type projections on the dorsal area of the last body segment. Immediately after birth, they start searching for food close to where they hatched. They feed on wood-borer insects on trees, or feed on their species' substrate or prey of choice. Feeding is the main purpose of the larval stage to prepare for pupation. Once their larval stage is complete the tree dwelling species make their way to the bottom of the tree to pupate. The pupal stage can last from 6 weeks to one year depending on the need to overwinter, and how short the overall lifecycle is for a particular species. A majority of clerid species pupate in earthen cells which are made from soil and certain enzymes secreted from their mouths. The rest remain in pupal cells. Adult beetles emerge from pupation and spend a variable time of their life maturing, and eventually oviposit. Sexually mature adults or imagos of Thanasiumus overwinter inside the wood-borer-infested trees and oviposit during the spring.
Cleridae