{"id":3871,"date":"2022-12-10T16:10:46","date_gmt":"2022-12-10T16:10:46","guid":{"rendered":"https:\/\/www.nivemnic.us\/?p=3871"},"modified":"2026-06-10T17:29:21","modified_gmt":"2026-06-10T21:29:21","slug":"eab-in-eastern-europe-worse-war","status":"publish","type":"post","link":"https:\/\/www.nivemnic.us\/?p=3871","title":{"rendered":"EAB in Eastern Europe – Worse (+ war!)"},"content":{"rendered":"
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A special issue of the journal Forests (Vol. 13 2022) seeks to improve understanding of the root causes of exacerbated threats from insect pests. The issue contains 15 papers; most focus on geographic areas other than North America. The journal is open access<\/strong>!<\/p>\n\n\n\n

Choi and Park (full citations below) link increased pest risk to climate change and increased international trade. They provide brief summaries of all 15 papers. My focus here is on two articles that provide updates on the status of the emerald ash borer (EAB <\/a>Agrilus planipennis<\/em>) in Russia and Ukraine. The article by Davydenko et al<\/em>. also examines interactions between EAB and the invasive pathogen Hymenoscyphus fraxineus<\/em>, which causes ash dieback disease<\/strong>. In other blogs I will look at insects linked to North America (both species from North America that threaten forests on other continents, and species in Russia that pose a threat to North America) and at the overall Russian experience.<\/p>\n\n\n\n

I blogged<\/a> about EAB invasion of Russia in April 2021 so this is an update.<\/p>\n\n\n\n

Musolin et al.<\/em> (2022) (full citations below) remind us that the EAB invasions of North America and Russia were detected almost simultaneously: in Michigan and Ontario in 2002 and in European Russia (Moscow) in 2003. They conclude that both invasions probably originated from a common source (most probably China). They date the introduction to the late 1980s or early 1990s; pathways might have been wooden crafts, wood packaging, or ash seedlings. Nate Siegert used dendrological studies to estimate a similar introduction date for the North American invasion.<\/p>\n\n\n\n

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European ash (Fraxinus excelsior<\/em>) specimen in Belgium; photo by Jean-Pol Granmont<\/figcaption><\/figure>\n\n\n\n

EAB has spread far in the intervening 30 + years. By early 2022, outbreaks were recorded in five Canadian provinces, 35 US states, 18 provinces and several cities in European Russia, and two provinces in Ukraine (Musolin et al. <\/em>2022) Davydenko et al<\/em>. report that EAB had also established in eastern Belarus, but provide no details.<\/p>\n\n\n\n

As demonstrated in the earlier blog and confirmed by Musolin et al. <\/em>(2022) and Davydenko et al<\/em>., the EAB has spread much faster to the southwest than directly West and to the Northwest. Davydenko et al.<\/em> attribute the slower spread in the St. Petersburg area to the colder and wetter climate of this region \u2013 which is ~1200 km north of Ukraine. While the EAB reproduces in two cohorts in Eastern Ukraine, to the north the beetle requires more than one year to complete its life cycle, at least two years in the St. Petersburg area. In 2021, Musolin et al<\/em>. 2021 speculated that pressure by the native parasitoid Spathius polonicus <\/em>Niezabitowski might also be slowing EAB\u2019s spread in the North. In 2022, Musolin does not address this possibility. (I note that APHIS has approved two Spathius<\/em> species as biocontrol agents in the U.S.).<\/p>\n\n\n\n

Musolin et al. <\/em>(2022) and Davydenko et al<\/em>. agree that the EAB poses real threat to ash in central and western Europe. In both the south (Davydenko et al<\/em>.) and in the northwestern area around St. Petersburg<\/a> ash grows in continuous stretches, linking Russia or Ukraine to Romania, Hungary, Slovakia, and Poland. These ash consist of both natural woodlands, and extensive plantings of both one of the European ash species, F. excelsior<\/em> and the highly-susceptible North America green ash (F. pennsyvanica<\/em>).  Furthermore, the EAB is an excellent hitchhiker on vehicles & railway cars. Davydenko et al<\/em>. also consider the beetle to be a strong flyer. Musolin et al.<\/em> (2022) cite a separate analysis in stating that EAB can probably invade most European countries. Only some regions of Norway, Sweden, Finland, Ireland, and Great Britain are probably protected by their low temperatures.<\/p>\n\n\n\n

Both articles were written too early to consider how the current war in the relevant area of Ukraine might affect spread of the EAB, although we know Ukrainians are cutting firewood. The war has certainly interrupted monitoring and other efforts.<\/p>\n\n\n\n

The sources agree on EAB\u2019s severe impacts. Musolin et al<\/em>. (2022) notes that the beetle has killed millions of trees in the forests and urban plantings in North America, European Russia, and Eastern Ukraine. Davydenko et al<\/em>. note that the Fraxinus<\/em> genus is one of the most widely distributed tree genera in North America. They then assert that the EAB could virtually eliminate it. I know that North American scientists agree that the beetle threatens many species in the genus; but do they agree that the genus would be \u201cvirtually eliminated\u201d?  Davydenko et al<\/em>. think the EAB could pose similar threat to Euro ash F. excelsior.<\/em><\/p>\n\n\n\n

Musolin et al<\/em>.  2022 estimate that potential economic losses in Europe could reach US$1.81 billion. By this indicator, the species ranks fourth among the most \u201ccostly\u201d invasive pests. Russia spent an estimated US$258.9 million between 2011 and 2016.<\/p>\n\n\n

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areas of Ukraine where studies conducted<\/figcaption><\/figure>\n<\/div>\n\n\n

Species\u2019 varying vulnerability<\/strong><\/p>\n\n\n\n

Musolin et al<\/em>. (2022) cite experience in the Moscow Botanical Garden as showing that only two Asian species — Chinese ash, F. chinensis<\/em>, and Manchurian ash, F. mandshurica — <\/em>are were resistant to the EAB. The beetle killed both North American ash (i.e., F. pennsylvanica <\/em>and F. americana<\/em>) and European ash (i.e., F. excelsior, F. angustifolia, <\/em>and F. ornus<\/em>).<\/p>\n\n\n\n

Experience in the field in Ukraine (Davydenko et al<\/em>.) suggests that F. excelsior <\/em>is less vulnerable to EAB than F. pennsyvanica.<\/em> The overwhelming majority of EAB infestations were found on the American species. Furthermore, although similar densities of EAB larvae were found in colonized branches of both species, the proportion of larvae that were viable was significantly higher on F. pennsyvnica <\/em>(91.4%) than on F. excelsior<\/em> (76.1%). However, the reverse was found in the Moscow and St. Petersburg regions. Davydenko et al<\/em>. don\u2019t address directly whether they think this discrepancy is attributable to climatic factors or to differences in vulnerability between trees growing in native forests vs.<\/em> human plantings. They did note that all observed cases of infestation of the native F. excelsior<\/em> in Ukraine occurred in artificial plantings rather than in natural woodlands.  <\/p>\n\n\n\n

Interactions with Ash Decline<\/strong><\/p>\n\n\n

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ash dieback disease – unfortunately pictured in the UK.
cc-by-sa\/2.0<\/a> – \u00a9 Adrian Diack<\/a> – geograph.org.uk\/p\/6497286<\/a><\/figcaption><\/figure>\n<\/div>\n\n\n

Davydenko et al. studied parts of Eastern Ukraine where EAB was entering areas already infected by the invasive ascomycete fungus Hymenoscyphus fraxineus<\/em> (cause of ash dieback, ADB). [Two of these regions — Luhansk and Kharkiv \u2013 have been the very center of the current war.] Other studies have shown that ~1 to 5% of F. excelsior <\/em>trees exhibit some resistance to ADB. These trees are thus a potential foundation for future propagation and restoration of ash in Europe \u2013 if<\/strong> enough of them survive attack by EAB.<\/p>\n\n\n\n

They found that F. excelsior <\/em>is more resistant to EAB than F. pennsylvanica<\/em>, but more susceptible to ADB.<\/p>\n\n\n\n

The Luhansk and Kharkiv regions have both EAB and ADB; the Sumy region has only the pathogen. EAB probably invaded the Luhansk region by 2016 (although it was detected only in 2019). The proportion of ash trees (both native and introduced species) infested rose from ~ 10\u201330% in 2019 to 60 – 90% by 2020\u20132021. The EAB arrived later in the Kharkiv region, to the Northwest, but the proportion of infested trees was similar by 2021. Combining the two regions, 75% of F. pennsylvanica <\/em>trees were EAB-infested, whereas only 31% of F. excelsior<\/em> trees were.<\/p>\n\n\n\n

Frequencies of infections by ADB were the reverse. Pooled data from all three study regions showed 21% of F. pennsylvanica<\/em> trees were infected vs.<\/em> 42% of F. excelsior<\/em>. In the plots invaded by both EAB and ADB (in Luhansk and Kherson regions), 4%of F. pennsylvanica <\/em>were affected by both invasive species vs.<\/em> 14% of F. excelsior<\/em> trees. Davydenko et al<\/em>. conclude that ADB facilitates EAB attack on F. excelsior<\/em> trees<\/p>\n\n\n\n

The impact of EAB is seen in the fact that overall mortality rates were higher in F. pennsylvanica<\/em> despite the fact that in the Sumy region mortality rates were higher in F. excelsior<\/em> because of the disease (EAB was absent from this region).  On the other hand, EAB infests and kills F. pennsylvanica<\/em> trees regardless of their prior health condition (i.e<\/em>., regardless of presence\/absence of ADB).<\/p>\n\n\n\n

Still, fewer than half the F. excelsior<\/em> trees in sites affected by both EAB & ADB (in Luhansk and Kherson regions) have died. Davydenko et al<\/em>. think the survivors constitute a source of material for eventual propagation. These trees need to be carefully mapped \u2013 a task certainly not facilitated by the war!<\/p>\n\n\n\n

Davydenko et al<\/em>. conclude that<\/p>\n\n\n\n

1. Invasion of EAB in Ukraine occurred 2\u20133 years before detection in 2019 [I think this is actually quite prompt for detection of EAB invasions]; the invasion is currently expanding both in terms of newly infested trees and invaded geographic area.<\/p>\n\n\n\n

2. Fraxinus excelsior<\/em> (at least when growing in the interior of forest stands) is more resistant to EAB than F. pennsylvanica<\/em> (when growing in field shelterbelts).<\/p>\n\n\n\n

3. Fraxinus excelsior <\/em>is more susceptible to ADB than F. pennsylvanica<\/em>.<\/p>\n\n\n\n

4. Infection by ADB is likely to predispose F. excelsior<\/em> to infestation by EAB.<\/p>\n\n\n\n

5. Ash trees infected by ADB are predisposed for the colonization by ash bark beetles Hylesinus<\/em> spp.  [I did not discuss these data.]<\/p>\n\n\n\n

6. Inventory and mapping of surviving F. excelsior<\/em>, affected by both ADB and EAB, is necessary to acquire genetic resources for the work on strategic, long-term restoration of devastated areas, thereby tackling a possible invasion of EAB to the EU.<\/p>\n\n\n\n

I was surprised that Musolin et al<\/em>. (2022) think EAB\u2019s host shift from local Asian ash species to introduced North America ash planted in the Russian Far East and China triggered EAB outbreaks in Eastern China that contributed to the beetle\u2019s introduction to North America and European Russia. American scientists apparently agree — Haack et al<\/em>. (2022) refer to both this episode and a similar to one posited for Asian longhorned beetle (Anoplophora glabripennis<\/a><\/em>) — that widespread planting of Populus<\/em> plantations led to rapid expansion of ALB in northern China, and the pest-weakened wood was then used in wood packaging. <\/p>\n\n\n\n

SOURCES<\/p>\n\n\n\n

Choi, W.I.; Park, Y.-S. Management of Forest Pests and Diseases. Forests 2022, 13, 1765. https:\/\/doi.org\/10.3390\/f13111765<\/a><\/p>\n\n\n\n

Davydenko, K.; Skrylnyk, Y.; Borysenko, O.; Menkis, A.; Vysotska, N.; Meshkova, V.; Olson, \u00c5.; Elfstrand, M.; Vasaitis, R. Invasion of emerald ash borer Agrilus planipennis and ash dieback pathogen Hymenoscyphus fraxineus in Ukraine-A concerted action. Forests 2022, 13, 789.<\/p>\n\n\n\n

Haack RA, Hardin JA, Caton BP and Petrice TR (2022) Wood borer detection rates on wood packaging materials entering the United States during different phases of ISPM#15 implementation and regulatory changes. Front. For. Glob. Change 5:1069117. doi: 10.3389\/ffgc.2022.1069117<\/p>\n\n\n\n

Musolin, D.L.; Selikhovkin, A.V.; Peregudova, E.Y.; Popovichev, B.G.; Mandelshtam, M.Y.; Baranchikov, Y.N.; Vasaitis, R. North-Westward Expansion of the Invasive Range of EAB, Agrilus planipennis Fairmaire (Coleoptera: Buprestidae) towards the EU: From Moscow to Saint Petersburg. Forests 2021, 12, 502. https:\/\/doi.org\/10.3390\/f12040502<\/p>\n\n\n\n

Musolin, D.L.; Kirichenko, N.I.; Karpun, N.N.; Aksenenko, E.V.; Golub, V.B.; Kerchev, I.A.; Mandelshtam, M.Y.; Vasaitis, R.; Volkovitsh, M.G.; Zhuravleva, E.N.; et al. Invasive insect pests of forests and urban trees in Russia: Origin, pathways, damage, and management. Forests 2022, 13, 521.<\/p>\n\n\n\n

Siegert, N.W.  2006.  17th USDA Interagency Research Forum on Gypsy Moth and Other Invasive Species. Annapolis, MD. January 10-13, 2006.<\/p>\n\n\n\n

<\/p>\n\n\n\n

Posted by Faith Campbell<\/p>\n\n\n\n

We welcome comments that supplement or correct factual information, suggest new approaches, or promote thoughtful consideration. We post comments that disagree with us — but not those we judge to be not civil or inflammatory.<\/p>\n\n\n\n

For a detailed discussion of the policies and practices that have allowed these pests to enter and spread \u2013 and that do not promote effective restoration strategies \u2013 review the Fading Forests report at http:\/\/treeimprovement.utk.edu\/FadingForests.htm<\/a><\/p>\n\n\n\n

or<\/p>\n\n\n\n

www.fadingforests.org<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"

A special issue of the journal Forests (Vol. 13 2022) seeks to improve understanding of the root causes of exacerbated threats from insect pests. The issue contains 15 papers; most focus on geographic areas other than North America. The journal is open access! Choi and Park (full citations below) link increased pest risk to climate … Continue reading EAB in Eastern Europe – Worse (+ war!)<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"_jetpack_feature_clip_id":0,"_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_publicize_message":"","jetpack_publicize_feature_enabled":true,"jetpack_social_post_already_shared":true,"jetpack_social_options":{"image_generator_settings":{"template":"highway","default_image_id":0,"font":"","enabled":false},"version":2},"jetpack_post_was_ever_published":false},"categories":[16,15,10,24,5,13,36],"tags":[],"class_list":["post-3871","post","type-post","status-publish","format-standard","hentry","category-conservation-priorities","category-drivers-of-extinction","category-forest-health-comblog","category-forest-pest-insects","category-forest-pests-comblog","category-invasive-species","category-other-realms"],"jetpack_publicize_connections":[],"jetpack_sharing_enabled":true,"jetpack_shortlink":"https:\/\/wp.me\/p65EGp-10r","jetpack_featured_media_url":"","_links":{"self":[{"href":"https:\/\/www.nivemnic.us\/index.php?rest_route=\/wp\/v2\/posts\/3871","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.nivemnic.us\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.nivemnic.us\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.nivemnic.us\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.nivemnic.us\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=3871"}],"version-history":[{"count":5,"href":"https:\/\/www.nivemnic.us\/index.php?rest_route=\/wp\/v2\/posts\/3871\/revisions"}],"predecessor-version":[{"id":3902,"href":"https:\/\/www.nivemnic.us\/index.php?rest_route=\/wp\/v2\/posts\/3871\/revisions\/3902"}],"wp:attachment":[{"href":"https:\/\/www.nivemnic.us\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=3871"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.nivemnic.us\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=3871"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.nivemnic.us\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=3871"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}