Red Bugs and Cedar Fences

Insect Identification

• Adult cedar bark beetles are shiny reddish brown insects. These pests usually measure 2 to 4 mm in length. Cedar bark beetle larvae are legless white grubs that have brown head capsules. These reddish colored bugs lay their eggs in cedar wood in galleries measuring 2 to 7 cm in length. Both the adult bark beetle and its larvae damage wood through feeding. Although cedar bark beetles typically attack live trees, fences and siding that have not been properly treated may be attacked also. These attacks usually begin where the wood makes contact with the soil.

Effects

• Cedar wood infested with cedar bark beetles may have damage on the inside of the wood from feeding larvae and adult beetles. Wood infested with these damaging pests often has a centipede pattern on the inside. Although cedar is considered resistant to heartwood decay, insect infestations can eventually damage the structure of a cedar fence.

Prevention

• Preventing insect infestations in your cedar fencing is best accomplished by applying wood preservatives. Cedar fences are also susceptible to damage from moisture and humidity, and wood preservatives can help prevent damage. Wood preservative treatments must be applied thoroughly, or the wood can split, providing insects with easy access to the wood.

Treatments

• Wood preservatives contain chemicals that make cedar and other wood toxic to insects and other wood-destroying organisms. According to the University of Kentucky, the wood preservatives most often used in wood for construction are creosote, water-borne preservatives and oil-borne preservatives. Wood is typically soaked in preservatives, or it can be applied with a brush. The level of effectiveness varies with the type of preservative used, the way it was applied and how much of the product penetrates the wood. Many homeowners think that purchasing pressure-treated wood protects their siding and fencing from damaging organisms and insects. However, even pressure-treated wood does not have adequate amounts of preservatives near the center of the wood to stave off bark beetles and other insects.