Emerald Ash Borer in Southwest Missouri: Identifying Decline and When Removal Is Safe

First detected in Missouri in 2008 and now confirmed across all 114 Missouri counties—including Barton, Jasper, Vernon, Lawrence, and Greene counties—the invasive Emerald Ash Borer (Agrilus planipennis) kills 99% of untreated native ash trees (Green, White, Blue, and Pumpkin Ash) within two to four years of infestation. While adult metallic-green beetles cause only minor leaf-nibbling, their larvae tunnel beneath the bark in S-shaped serpentine galleries that sever the tree’s phloem and cambium.

As larval feeding density increases, the tree is completely girdled, cutting off water and carbohydrate transport between the root system and upper canopy.

Look for these verified field indicators on ash trees around Golden City, Carthage, Lamar, and Joplin: progressive upper-canopy thinning and dieback, distinct 1/8-inch D-shaped adult exit holes in the bark, and heavy woodpecker foraging that strips outer bark plates into bright, pale patches known as "blonding."

As the tree struggles to compensate for its severed vascular system, you will also frequently see clusters of vertical epicormic shoots (water sprouts) emerging along the lower trunk and root flare, alongside vertical bark splits exposing winding larval galleries underneath.

Arboricultural biomechanics research shows that unlike oaks or maples that retain structural wood strength for a period after dying, EAB-infested ash wood suffers rapid internal moisture loss and microscopic checking early in the decline process. Once canopy dieback exceeds 30% to 50%, ash branches and stems become extraordinarily brittle and prone to sudden, non-ductile shear failures near branch unions or at the base.

Because dead or late-stage EAB ash trees can shatter unpredictably under rigging loads or climbers’ weight, removing compromised ash trees across your Southwest Missouri property before they stand dead for a year or more is safer, more predictable, and significantly more cost-effective.