The emerald ash borer (Agrilus planipennis Fairmaire, 1888, Coleoptera: Buprestidae), abbreviated as EAB, originates from Northeast Asia, particularly the Far East where it infested Manchurian ash. At the end of the last century, EAB was detected almost simultaneously in North America and Russia. Within 20 years, the pest has spread to 37 U.S. states, 5 Canadian provinces, and 20 Russian regions.

In Ukraine, EAB was first detected in 2019 in Luhansk Oblast, but judging by the presence of exit holes, it had penetrated the region at least two years earlier. Currently, it hasn't been found anywhere else in Europe. However, given its rapid spread rate, scientists and practitioners are concerned about the fate of ash trees, which have already suffered from chalara necrosis for about 20 years.

Initially, EAB was included in the quarantine list of the European and Mediterranean Plant Protection Organization (EPPO), but after confirmation of its presence in Europe, particularly in Ukraine, it was moved to the A2 list as a species already present in the territory.

Despite EAB spreading across Ukraine for several years and being detected in Luhansk, Kharkiv, and Kyiv oblasts, it remains on the A1 list ("Quarantine organisms absent in Ukraine") of the State Service of Ukraine on Food Safety and Consumer Protection. Its presence even on the A2 list ("Quarantine organisms with limited distribution in Ukraine") is questionable, similar to the situation with the American white butterfly, which is now widespread in almost all regions of Ukraine.

Under these conditions, the only apparent solution is to cut down all ash trees bordering infested areas. This also prevents the identification of resistant specimens for subsequent propagation and use in restoring destroyed plantations, which exist in any population. This situation encourages ignoring the facts of EAB presence in certain plantations and administrative regions of the country.

Meanwhile, European scientists are concerned, and the Commission on Quarantine Forest Pests (EPPO) formed a network of experts in October 2022 for EAB surveillance, monitoring and control. Thanks to this network, which includes Ukrainian scientists, regular bulletins with new publications about EAB are issued, a webpage was created, and webinars are organized.

The latest webinar dedicated to EAB in the EPPO region and countries' preparedness for its further spread took place on December 5. EPPO intends to create a dynamic map of EAB distribution. Therefore, representatives from countries where EAB presence is already confirmed and neighboring countries were invited, including Estonia, Finland, Latvia, and Kazakhstan, which shares a border with Russian regions where EAB has already been recorded.

During the webinar, symptoms and signs of ash tree infestation by EAB were presented. Symptoms reflect tree reactions (thinning and dying crowns, water sprout formation), while signs characterize the pest (specific gallery shape, exit holes, adult leaf feeding). EAB can spread through active flight (up to 10 km), with plant material and harvested wood, or by "hitchhiking" on any vehicles.

Tree inspection remains the most common method for EAB detection. One symptom is feeding traces from birds, particularly woodpeckers, with bark pieces removed in winter being clearly visible on snow. However, birds cannot completely destroy a pest outbreak. Similarly, parasitoids only reproduce sufficiently in the 3rd-4th year of an outbreak's existence, and these entomophages may also consume insects of other species besides EAB.

Participants concluded that stopping EAB spread is impossible. Current research includes trunk insecticide injections, soil drenching with insecticides, and parasitoid releases, but all provided only short-term protection. It's crucial to preserve resistant ash specimens and, in cases of inevitable tree death, obtain wood that won't serve as a pest source. Despite over 20 years of EAB research in various regions, many questions remain unanswered.