{"id":30049,"date":"2024-10-12T09:30:31","date_gmt":"2024-10-12T13:30:31","guid":{"rendered":"https:\/\/www.purdue.edu\/fnr\/extension\/?p=30049"},"modified":"2025-02-13T15:42:09","modified_gmt":"2025-02-13T19:42:09","slug":"new-threat-to-north-american-elms-purdue-landscape-report","status":"publish","type":"post","link":"https:\/\/www.purdue.edu\/fnr\/extension\/new-threat-to-north-american-elms-purdue-landscape-report\/","title":{"rendered":"New Threat to North American Elms – Purdue Landscape Report"},"content":{"rendered":"

Purdue Landscape Report<\/a>: The elm zigzag sawfly (EZS),\u00a0Aproceros leucopoda<\/em>, is a non-native insect recently detected in several midwestern states. Originally from eastern Asia, this insect is rarely considered a problem in its native range, having several natural enemies and environmental factors able to keep it in check.<\/p>\n

\"zigzag<\/a>

Figure 1. Elm zigzag sawfly adult, Gyorgy Csoka, Hungary Forest Research Institute, Bugwood.org<\/p><\/div>\n

However, when in new landscapes, aspects of this insect\u2019s life cycle enhance its ability to spread across new habitats and do significant damage to its host plant, the elm tree. EZS was first detected outside of its native range in Europe in 2003. Then, in 2020, it was found in North America for the first time in Quebec. It has since been detected in several states in the US, spreading first through the Northeast before entering the Midwest. It has not yet been detected in Indiana, but has been in the surrounding area.<\/p>\n

Elm zigzag sawfly is a member of the insect order Hymenoptera, which includes bees, ants, and wasps. More specifically, sawflies belong to a suborder known as Symphyta, whose members are noted for a broad-waisted appearance and a saw-shaped ovipositor. Sawflies are a fairly common group of insects, though observers will often overlook them or confuse them for other insects. Adult EZS are generally small, darkly-colored insects that are easy to write off as \u2018just another black bug\u2019 you see around the garden or yard (Fig. 1).<\/p>\n

\"Zigzag<\/a>

Figure 2. Elm zigzag sawfly larva feeding, Gyorgy Csoka, Hungary Forest Research Institute, Bugwood.org<\/p><\/div>\n

They resemble wasps, but possess a broad waist with no narrowing of space between the thorax and abdomen, and they lack a stinger. EZS larvae closely resemble caterpillars in both form and feeding habits, with pale green coloration, a black stripe that runs down the length of the body, and dark T-shaped markings on the legs (Fig. 2). The larvae, like moth and butterfly caterpillars, will also possess six pairs of fleshy prolegs that are lost upon reaching maturity. While the larvae bear chewing mouthparts to consume the leaf material of many kinds of plants, the adults are nectar and pollen-feeding. It should be noted that EZS larvae chew zigzag patterns into elm leaves, thus the common name of the insect. Like bees and wasps, sawflies also possess wings, but are typically lazy fliers, choosing to fly only during warm, sunnier periods of the day.<\/p>\n

View the rest of the article here: A New Threat to Elms in North America<\/a><\/p>\n

Subscribe and receive the newsletter:\u00a0Purdue Landscape Report Newsletter<\/a>.<\/p>\n

Resources:
\n<\/strong>Intro to Trees of Indiana: American Elm<\/a>, Got Nature? Blog, Purdue Extension \u2013 FNR
\nIntro to Trees of Indiana: Slippery Elm<\/a>, Got Nature? Blog, Purdue Extension \u2013 FNR
\nID That Tree<\/a>, Playlist, Red Elm, Siberian Elm, Winged Elm, Purdue Extension \u2013 Forestry and Natural Resources (FNR) YouTube Channel
\n<\/strong>ID That Tree<\/a>, Playlist, Purdue Extension \u2013 FNR YouTube Channel
\nInvasive Species Playlist<\/a>, Playlist, Purdue Extension – FNR YouTube Channel
\nA Woodland Management Moment<\/a>, Playlist, Purdue Extension \u2013 FNR YouTube Channel
\nWoodland Stewardship for Landowners<\/a>, Playlist, Purdue Extension \u2013 FNR YouTube Channel
\nIndiana Department of Natural Resources: Invasive Species<\/a>
\nIndiana Invasive Species Council<\/a>
\nCooperative Invasive Species Management Area (CISMA)<\/a>
\nReport Invasive<\/a>, Purdue Extension
\nEpisode 11 \u2013 Exploring the challenges of Invasive Species<\/a>, Habitat University-Natural Resource University
\nWhat are invasive species and why should I care?<\/a>, Got Nature? Blog, Purdue Extension – FNR
\nNative Trees of the Midwest<\/a>, The Education Store, Purdue Extension’s resource center
\nInvesting in Indiana Woodlands<\/a>, The Education Store
\nForest Improvement Handbook<\/a>, The Education Store<\/p>\n

Bob Bruner<\/a>, Exotic Forest Pest Educator
\nPurdue Entomology<\/p>\n","protected":false},"excerpt":{"rendered":"

Purdue Landscape Report: The elm zigzag sawfly (EZS),\u00a0Aproceros leucopoda, is a non-native insect recently detected in several midwestern states. Originally from eastern Asia, this insect is rarely considered a problem in its native range, having several natural enemies and environmental factors able to keep it in check. However, when in new landscapes, aspects of this […]<\/p>\n","protected":false},"author":62,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[42,47,54,622],"tags":[1999,1158,60,65,367,895,408,495],"class_list":["post-30049","post","type-post","status-publish","format-standard","hentry","category-forestry","category-invasiveinsects","category-wildlife","category-woodlands","tag-elm","tag-exotic-insects","tag-forestry","tag-invasive-insects","tag-invasive-species","tag-purdue-landscape-report","tag-trees","tag-woodlands","audience-for-enthusiasts","audience-for-homeowners","audience-for-landowners","audience-for-professionals"],"acf":[],"aioseo_notices":[],"publishpress_future_action":{"enabled":false,"date":"2026-04-19 18:21:03","action":"change-status","newStatus":"draft","terms":[],"taxonomy":"category","extraData":[]},"publishpress_future_workflow_manual_trigger":{"enabledWorkflows":[]},"_links":{"self":[{"href":"https:\/\/www.purdue.edu\/fnr\/extension\/wp-json\/wp\/v2\/posts\/30049","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.purdue.edu\/fnr\/extension\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.purdue.edu\/fnr\/extension\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.purdue.edu\/fnr\/extension\/wp-json\/wp\/v2\/users\/62"}],"replies":[{"embeddable":true,"href":"https:\/\/www.purdue.edu\/fnr\/extension\/wp-json\/wp\/v2\/comments?post=30049"}],"version-history":[{"count":7,"href":"https:\/\/www.purdue.edu\/fnr\/extension\/wp-json\/wp\/v2\/posts\/30049\/revisions"}],"predecessor-version":[{"id":31875,"href":"https:\/\/www.purdue.edu\/fnr\/extension\/wp-json\/wp\/v2\/posts\/30049\/revisions\/31875"}],"wp:attachment":[{"href":"https:\/\/www.purdue.edu\/fnr\/extension\/wp-json\/wp\/v2\/media?parent=30049"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.purdue.edu\/fnr\/extension\/wp-json\/wp\/v2\/categories?post=30049"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.purdue.edu\/fnr\/extension\/wp-json\/wp\/v2\/tags?post=30049"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}