Tree Pests

Tree Pests is a collaborative effort of several state and federal agencies to keep citizens informed of the latest invasive insect and disease threats to Missouri's trees. Whether it is a single tree in your yard or acres of woodlands on your property, this site is for you.

Do you know that humans are a primary way these invasive pests are spread? It's true! Whether through moving firewood or wood to make furniture and crafts, we enable these hitchhiking freeloaders to spread from infected areas to noninfected ones. The "Slow the spread" Web pages for each pest contain the latest tips on how you can help us in the fight against these invasive threats.

EAB update

Thirty states now have confirmed populations of the emerald ash borer, with Alabama and Oklahoma being the latest states added to the list. Here in Missouri, 33 counties and the City of St. Louis have confirmed reports of EAB.

With cumulative degree-days running ahead of both last year and the 30-year average, expect the annual emergence of adult beetles to be ahead of schedule. The degree-day emergence and peak activity map will be updated every Friday.

With the emergence of the adults and females laying eggs, larval development will follow in the coming weeks. As the larvae grow and develop, they will disrupt the tree’s ability to move water up from the roots to the leaves and nutrients from the leaves back down to the roots.

Keep in mind one of the telltale early symptoms indicating your tree might be EAB-infested will be woodpeckers pecking away layers of the outer bark in an effort to reach the larvae. This leads to what the experts refer to as ‘blonding’.

Go to the EAB signs and symptoms page for more information