Insects are a natural and integral component of forests. Though many insects play fundamental roles in helping forest ecosystems function, other insects cause significant damage to trees and threaten our woodlands.
In Kansas alone, an estimated 15,000-20,000 insect species exist. While highly variable in size, behavior, and ecological role, a small number pose serious and significant threats to the health and sustainability of our Kansas forests.
First detected in the United States in 2002, the emerald ash borer (EAB) is a small but destructive invasive insect that feeds on andultimately kills ash trees. Since its arrival, EAB has spread to at least 37 states, including Kansas, where it was first confirmed in 2012. This is significant and concerning news for Kansas, which is home to an estimated 65 million ash trees – approximately 93% of which are found on privately-owned forest land. Today, EAB continues to expand into new areas of our state, placing rural, urban, and riparian forests at risk.
Since its initial discovery in Michigan and Ontario (2002), Emerald Ash Borer (Agrilus planipennis Fairmaire) has expanded its range further into Canada and from the mid-west to the eastern part of the United States. It has been detected in at least 24 states, including Kansas in 2012. Wyandotte (2012), Johnson (2013), Leavenworth (2014), Douglas (2015), Jefferson (2015), Atchison (2016), Doniphan (2017), Shawnee (2017), Miami (2019), Jackson (2019), Brown (2022), Osage (2022), Franklin (2023), Lyon (2024), Nemaha (2024), Linn (2025), Pottawatomie (2025), and Bourbon (2025) are the Kansas counties where EAB has been found.
If you live in a county where EAB has already been detected and you have questions about removing or protecting your ash trees, please contact a certified arborist for assistance.
Our forests continue to face the ongoing risk of new harmful insect infestations. Among the most concerning current threats are the Asian longhorned beetle, spotted lanternfly, walnut twig beetle, and spongy moth. Each of these insects has the potential to weaken the vitality of our woodlands and cause significant ecological and economic harm.
Not all insects found in trees and forests are considered serious threats; however, many can cause damage ranging from minor aesthetic issues to chronic injury that reduces tree vigor and increases susceptibility to other stressors.
The Kansas Forest Service forest health program provides statewide assistance to rural landowners and communities on forest and shade tree pests and diseases or invasive species that target wooded areas. For individual sick tree questions, please reach out to your local K-State Extension Office.
