Learn How Verbenone Works

beetle kill in Rocky Mountain National Park

Verbenone repels Mountain Pine Beetles.
Without a host tree in which to lay eggs, they die without reproducing and end their life cycle.



Large areas of beetle kill in Rocky Mountain National Park

Mountain Pine Beetle

Verbenone Pine Beetle Repellent helps protect your high-value pine trees.

The Pine Beetle is the most destructive forest pest in North America. The Canadian Forest Service describes the current pine beetle epidemic as the largest insect infestation in North American history. It has been going on for over 20 years.

Mountain Pine Beetles have a one year life cycle in most of the Rocky Mountains. In late summer (usually July-Aug in Rocky Mountain States and BC) the newly hatched adults leave the tree of their metamorphosis, seeking out larger trees (usually over 13" diameter if possible) in the surrounding area. (In areas with heavy infestation, beetle hatchlings may take even smaller trees as pressure to get ANY tree increases). When the adults arrive, they begin tunnelling under the bark, lay eggs, which turn to larvae and live through the winter to produce more egg-laying adults in the late Spring or Summer.

It is estimated that one infested tree will will hatch swarms that kill at least two more trees and possibly more.

While Bark Beetles have been around for millennia, and while they have been known to cycle through the forest periodically, there are factors at play that have not previously been so prevalent. Because forest temperatures are warming, the beetles are not being frozen out during the coldest part of the winter. Warming temperatures also bring draught. Draught is weakening trees, which then become more susceptible to beetle-born disease. For these reasons, there seems no end in sight until the trees are gone unless we protect the forests.

Verbenone and how it works.

It is not the actual Pine Beetle that kills your tree. The Beetle vectors several pathogenic fungi which facilitate successful colonization and tree mortality. There are no survivors from a successful attack. When a beetle-attacked tree is cut down, you can usually see the blue stain fungus that has colonized the tree (introduced by the beetle). It is the fungus that kills the tree. As there is no cure for the fungi, we must deter the beetles.

Beetles and other insects communicate using pheromones. Verbenone (whether pouch or paste) is a synthetic pheromone that replicates the beetle pheromone, sending a message to arriving swarms that the tree is full and that the food supply is insufficient for additional beetles. Arriving beetles receive the "message" that they should look elsewhere for a suitable host.

Easy-to-use controlled-release dispensers or paste are applied on individual trees or placed in a grid pattern when wanting to protect acreage. Prevailing breezes carry the "plume" of pheromone in the direction of the trees being protected.

Because beetles are not strong flyers, their next tree host must be within a short distance. If that home is "full", they must continue travelling until they reach a good tree. By forcing them to fly further and further, they succumb to exhaustion or simply can't find a suitable host and land in an inhospitable place where they die.

The tree below has been successfully attacked by beetles. The white pitch wads are the tree's way of trying to trap and kill the beetles. If the tree is full of water (not draught-weakened), it is sometimes successful. However, a tree so heavily attacked is a potential mother-load of beetles that will hatch and spread the contagion next year. It must be cut and burned.

Tree with pitch

Verbenone helps control:

  • Mountain Pine Beetle (Dendractonus ponderosae)
  • Pine Engraver - Ips pini (only partially successful)
  • Northern Spruce Engraver - Ips perturbatus (only partially successful)
  • California Five-spined Ips - Ips paraconfusus (only partially successful)
  • Southern Pine Beetle (Dendroctonus frontalis)
  • Western Pine Beetle (Dendroctonus brevicomus)

And can be used on:

  • Lodgepole Pine
  • Ponderosa Pine
  • Whitebark Pine
  • Western White Pine
  • Southwestern White Pine
  • Pinyon Pine
  • Sugar Pine
  • Limber Pine
  • Loblolly Pine and other susceptible pine species.

Does Verbenone really work?

Verbenone has been used as part of integrated pest management programs (IPM) for more than a decade. Many studies show that areas treated with Verbenone, as part of an IPM program, fare significantly better than those that are not. Commercially used by Forest Service, State Agencies, Recreation Areas, Home Owner's Associations in high value recreational or private land holdings.

How safe is Verbenone?

Verbenone Pouch is considered a "soft" pest control product and can be used in environmentally sensitive habitats. It is environmentally safe and non-toxic to humans, pets, birds, and even the beetles themselves. Registered by EPA and most Rocky Mountain States. All pheromones in controlled release dispensers are approved organic by USDA/NOP. It is user and Eco-Friendly. Unlike the insecticides approved for Mt. Pine Beetle control,Verbenone does not kill bees, beneficial insects, aquatic organisms. The EPA classifies it as CAUTION, which is indicative of needing the lowest level of concern in regards to insecticides. Not restricted use. (Always follow label instructions.)

General Use of Verbenone:

Easy-to-use controlled-release dispensers or paste are applied on individual trees or placed in a grid pattern when wanting to protect acreage. Placed approx 6-7' high on the north face of the tree (where there is more shade) or downwind of prevailing breezes so that the "plume" of pheromone will waft in the direction of the trees being protected.