Bark beetles go through four stages of life: egg, larvae, pupae, and adult, with the time to develop often relying on the species as well as the current temperature.

Bark beetles also have small appendages, with antennae that can be folded into the body and large mandibles to aid in the excavation of woody tissue.

In defense, healthier trees may produce sap, resin or latex, which often contains a number of insecticidal and fungicidal compounds that can kill, injure, or immobilize attacking insects.

Chemical compounds can also be induced by tree species that bind with amino acids in the gut of bark beetles, reducing their ability to process woody materials.

[3] When in large quantities, the sheer number of beetles can overwhelm the tree's defenses with resulting impacts on the lumber industry, water quality, fish and wildlife, and property values.

[13] The braconid wasp Spathius canadensis is known to parasitize the native elm bark beetle Hylurgopinus rufipes.

Ambrosia beetles carry the fungal spores in either their gut or special structures, called mycangia, and infect the trees as they attack them.

[16] These chemicals interact with pine trees[17] as the bark beetle's host, based on the behavioral, physiological, and biochemical effects of monoterpenes.

[17] Monoterpenes are a chemical fragrance that plays a significant role in tree-insect interactions, specifically within pine trees.

Massive outbreaks of mountain pine beetles in western North America after about 2005 have killed millions of acres of forest from New Mexico to British Columbia.

[21] Like many other insects, Scolytinae emit pheromones to attract conspecifics, which are thus drawn to trees already colonized by bark beetles.

[23] Increases in international trade, as well as the use of wood containers for storage, has aided numerous species of bark beetle in spreading across the world.

As a third the result of global warming, the breeding season of the bark beetle is extended, meaning that number of generations per year will increase.