{"id":33163,"date":"2025-05-23T08:34:57","date_gmt":"2025-05-23T12:34:57","guid":{"rendered":"https:\/\/www.purdue.edu\/fnr\/extension\/?p=33163"},"modified":"2025-08-06T09:05:44","modified_gmt":"2025-08-06T13:05:44","slug":"sawflies-caterpillar-pests-but-not-caterpillars-plr","status":"publish","type":"post","link":"https:\/\/www.purdue.edu\/fnr\/extension\/sawflies-caterpillar-pests-but-not-caterpillars-plr\/","title":{"rendered":"Sawflies: Caterpillar Pests but not Caterpillars &#8211; PLR"},"content":{"rendered":"<p><a href=\"https:\/\/purduelandscapereport.org\/article\/sawflies-the-caterpillar-pests-that-are-not-caterpillars\/\" target=\"_blank\" rel=\"noopener\"><em>Purdue Landscape Report<\/em><\/a>: Sawflies are frequent pests in the landscape that attack a wide variety of plants, from ornamental flowers to large trees. You might start to see them damaging plants around this time of year as the first generations hatch and begin to feed on foliage. They are often mistaken for caterpillars, which are the larval stages of butterflies and moths (Order Lepidoptera). However, sawflies are actually wasp-like insects (Order Hymenoptera).<\/p>\n<p>Let\u2019s review how to tell them apart. Products that are labeled for caterpillars do not always work on sawflies, so proper identification is important.<\/p>\n<ul>\n<li>The most reliable characteristic are the prolegs. Sawflies have 6+ pairs of prolegs, or false legs, while caterpillars have &lt; 6 pairs of prolegs. (Fig. 1)<\/li>\n<li>When disturbed, sawflies will lift their posterior into an \u201cS\u201d shape. Caterpillars don\u2019t display this behavior. (Fig. 2)<\/li>\n<\/ul>\n<div class=\"row\" style=\"align-items: center\">\n<div class=\"col-md-6\">\n<figure style=\"text-align: center\"><a href=\"https:\/\/www.purdue.edu\/fnr\/extension\/wp-content\/uploads\/2025\/05\/fig-1-sawfly-caterpillar-768x225-1.jpg\" data-rel=\"lightbox-image-0\" data-rl_title=\"\" data-rl_caption=\"\" title=\"\"><br \/>\n<img decoding=\"async\" class=\"img-fluid alignnone\" style=\"height: 126px;width: auto;object-fit: cover;margin: 0 auto\" src=\"https:\/\/www.purdue.edu\/fnr\/extension\/wp-content\/uploads\/2025\/05\/fig-1-sawfly-caterpillar-768x225-1.jpg\" \/> <\/a><figcaption>Figure 1. Left: Sawfly larvae. Image: John Obermeyer, Purdue University. Right: Tomato hornworm. <em>Image: Gerald Holmes, Strawberry Center, Cal Poly San Luis Obispo.<\/em><\/figcaption><\/figure>\n<\/div>\n<div class=\"col-md-6\" style=\"text-align: left\">\n<figure style=\"text-align: center\"><a href=\"https:\/\/www.purdue.edu\/fnr\/extension\/wp-content\/uploads\/2025\/05\/fig-2-sawfly-s-shape-679x450-1.jpg\" data-rel=\"lightbox-image-1\" data-rl_title=\"\" data-rl_caption=\"\" title=\"\"><br \/>\n<img decoding=\"async\" class=\"img-fluid alignnone\" style=\"height: 331px;width: auto;object-fit: cover;margin: 0 auto\" src=\"https:\/\/www.purdue.edu\/fnr\/extension\/wp-content\/uploads\/2025\/05\/fig-2-sawfly-s-shape-679x450-1.jpg\" alt=\"Figure 2. Sawflies displaying characteristic \u201cS\u201d shape. Image (PLR): Gyorgy Csoka, Hungary Forest Research Institute.\" \/><br \/>\n<\/a><figcaption>Figure 2. Sawflies displaying characteristic \u201cS\u201d shape. <em>Image: Gyorgy Csoka, Hungary Forest Research Institute<\/em>.<\/figcaption><\/figure>\n<\/div>\n<\/div>\n<p><em>Integrated management recommendations<\/em><\/p>\n<p>Early in the year, before hatching starts, look for sawfly oviposition on your plants. This will vary depending on the species of sawfly. For example, the European Pine sawfly eggs look like yellow-orange spots evenly spaced on the needles (Fig. 3). The Bristly Roseslug sawfly uses her ovipositor to cut a slit into the leaf petiole where she inserts eggs. The gooseberry sawfly lays eggs on a leaf vein (Fig. 4).<\/p>\n<div class=\"row\" style=\"align-items: center\">\n<div class=\"col-md-6\">\n<figure style=\"text-align: center\"><a href=\"https:\/\/www.purdue.edu\/fnr\/extension\/wp-content\/uploads\/2025\/05\/fig-3-european-pine-sawfly-eggs-675x450-1.jpg\" data-rel=\"lightbox-image-2\" data-rl_title=\"\" data-rl_caption=\"\" title=\"\"><br \/>\n<img decoding=\"async\" class=\"img-fluid alignnone\" style=\"height: 333px;width: auto;object-fit: cover;margin: 0 auto\" src=\"https:\/\/www.purdue.edu\/fnr\/extension\/wp-content\/uploads\/2025\/05\/fig-3-european-pine-sawfly-eggs-675x450-1.jpg\" \/> <\/a><figcaption>Figure 3. European pine sawfly eggs. <em>Image: A. Steven Munson, USDA Forest Service.<\/em><\/figcaption><\/figure>\n<\/div>\n<div class=\"col-md-6\" style=\"text-align: left\">\n<figure style=\"text-align: center\"><a href=\"https:\/\/www.purdue.edu\/fnr\/extension\/wp-content\/uploads\/2025\/05\/fig-4-gooseberry-sawfly-eggs-675x450-1.jpg\" data-rel=\"lightbox-image-3\" data-rl_title=\"\" data-rl_caption=\"\" title=\"\"><br \/>\n<img decoding=\"async\" class=\"img-fluid alignnone\" style=\"height: 333px;width: auto;object-fit: cover;margin: 0 auto\" src=\"https:\/\/www.purdue.edu\/fnr\/extension\/wp-content\/uploads\/2025\/05\/fig-4-gooseberry-sawfly-eggs-675x450-1.jpg\" alt=\"Figure 4. Gooseberry sawfly eggs. Image: Whitney Cranshaw, Colorado State University.\" \/><br \/>\n<\/a><figcaption>Figure 4. Gooseberry sawfly eggs. <em>Image: Whitney Cranshaw, Colorado State University.<\/em><\/figcaption><\/figure>\n<\/div>\n<\/div>\n<p>&nbsp;<\/p>\n<p>If the eggs are readily visible, manual removal will help reduce the populations. This is best accomplished in early spring before the eggs hatch. Use a tool to smash the eggs, or prune of the affected plant material.<\/p>\n<p>You may not notice any problem on the plant until you start to see holes appearing in the foliage. Monitor regularly in the spring for holes and \u201cwindow pane\u201d damage (Fig. 5). This is the time of year when sawflies are hatching, so don\u2019t wait any longer to check your plants. Sawfly management is best accomplished when the larvae are still small. Prune or shake off the larvae from the plant, or spray with a biorational material so as not to disturb natural enemies and cause a secondary pest outbreak later in the summer.<\/p>\n<figure style=\"text-align: center\"><a href=\"https:\/\/www.purdue.edu\/fnr\/extension\/wp-content\/uploads\/2025\/05\/fig-5-bristly-roseslug-damage-676x450-1.jpg\" data-rel=\"lightbox-image-4\" data-rl_title=\"\" data-rl_caption=\"\" title=\"\"><img decoding=\"async\" class=\"img-fluid aligncenter\" style=\"height: 333px;width: auto;object-fit: cover;margin: 0 auto\" src=\"https:\/\/www.purdue.edu\/fnr\/extension\/wp-content\/uploads\/2025\/05\/fig-5-bristly-roseslug-damage-676x450-1.jpg\" alt=\"Figure 5. Bristly roseslug feeding damage. Brian Kunkel, University of Delaware.\" \/><\/a><figcaption>Figure 5. Bristly roseslug feeding damage. <em>Image: Brian Kunkel, University of Delaware.<\/em><\/figcaption><\/figure>\n<p>&nbsp;<\/p>\n<p>For more information on sawfly biology, check out this five-minute video:\u00a0<a href=\"https:\/\/www.youtube.com\/watch?v=IWe4vyhGpuk&amp;list=PLgavttJPLt2QF5ZEUzGfA5hg2qSOdiT2c&amp;index=11\" target=\"_blank\" rel=\"noopener\">Slaying Sawflies with Purdue Plant Doctor<\/a>.<\/p>\n<p>Specific management recommendations can be found on the\u00a0<a href=\"https:\/\/www.purdueplantdoctor.com\/\" target=\"_blank\" rel=\"noopener\">Purdue Plant Doctor<\/a>\u00a0website. Type \u201csawfly\u201d into the search and click on the species you would like to read more about!<\/p>\n<p>Read the original article on <a href=\"https:\/\/purduelandscapereport.org\/article\/sawflies-the-caterpillar-pests-that-are-not-caterpillars\/\" target=\"_blank\" rel=\"noopener\">Purdue Landscape Report: Sawflies: the caterpillar pests that are not caterpillars<\/a>.<\/p>\n<div class=\"clearfix\"><strong>Resources:<br \/>\n<\/strong><a href=\"https:\/\/www.purdue.edu\/fnr\/extension\/facebook-live-ask-the-expert-pests-in-your-woods\/\" target=\"_blank\" rel=\"noopener\">Ask the Expert: Pests in Your Woods<\/a>, Purdue Extension \u2013 Forestry &amp; Natural Resources (FNR) YouTube Channel<br \/>\n<a href=\"https:\/\/www.purdue.edu\/fnr\/extension\/report-spotted-lanternfly-purdue-landscape-report\/\" target=\"_blank\" rel=\"noopener\">Report Spotted Lanternfly<\/a>, Purdue Landscape Report<br \/>\n<a href=\"https:\/\/www.youtube.com\/playlist?list=PLgoGnq-fak7VPjD7DpNPWCoNrhCdBFUIt\" target=\"_blank\" rel=\"noopener\">Invasive Species Playlist<\/a>, Purdue Extension &#8211; FNR YouTube Channel<br \/>\n<a href=\"https:\/\/www.in.gov\/dnr\/rules-and-regulations\/invasive-species\/\" target=\"_blank\" rel=\"noopener\">Indiana Department of Natural Resources: Invasive Species<\/a><br \/>\n<a href=\"https:\/\/www.entm.purdue.edu\/iisc\/\" target=\"_blank\" rel=\"noopener noreferrer\">Indiana Invasive Species Council<\/a><br \/>\n<a href=\"https:\/\/www.sicim.info\/cismas\" target=\"_blank\" rel=\"noopener\">Cooperative Invasive Species Management Area (CISMA)<\/a><br \/>\n<a href=\"https:\/\/ag.purdue.edu\/reportinvasive\/\" target=\"_blank\" rel=\"noopener\">Report Invasive<\/a>, Purdue Extension<br \/>\n<a href=\"https:\/\/www.purdue.edu\/fnr\/extension\/invasive-species\/\" target=\"_blank\" rel=\"noopener\">What are invasive species and why should I care?<\/a>, Got Nature? Blog, Purdue Extension &#8211; FNR<br \/>\n<a href=\"https:\/\/www.purdueplantdoctor.com\/\" target=\"_blank\" rel=\"noopener\">Purdue Plant Doctor<\/a>, Purdue Extension<br \/>\n<a href=\"https:\/\/edustore.purdue.edu\/4-h-15-80a.html\" target=\"_blank\" rel=\"noopener\">An Introduction to Trees of Indiana<\/a>, The Education Store, Purdue Extension&#8217;s resource center<br \/>\n<a href=\"https:\/\/ag.purdue.edu\/department\/fnr\/fifty-tree-library\/index.html\" target=\"_blank\" rel=\"noopener\">Fifty Common Trees of Indiana<\/a>, Forestry &amp; Natural Resources<strong><br \/>\n<\/strong><a title=\"ID That Tree Youtube Channel Playlist\" href=\"https:\/\/www.youtube.com\/playlist?list=PLgoGnq-fak7V9w3jf2Sj_6-pNaw4sX4Ga\" target=\"_blank\" rel=\"noopener noreferrer\">ID That Tree<\/a>, Playlist, Purdue Extension \u2013 FNR YouTube Channel<br \/>\n<a href=\"https:\/\/www.youtube.com\/watch?v=_yK8tstEacE&amp;list=PLgoGnq-fak7VTTnF4Bh9HvQnB_azYbAfY\" target=\"_blank\" rel=\"noopener noreferrer\">A Woodland Management Moment<\/a>, Playlist, Purdue Extension \u2013 FNR YouTube Channel<br \/>\n<a href=\"https:\/\/www.youtube.com\/playlist?list=PLgoGnq-fak7XgiEFkpuQNAFa0rM4elCis\" target=\"_blank\" rel=\"noopener\">Woodland Stewardship for Landowners<\/a>, Playlist, Purdue Extension \u2013 FNR YouTube Channel<br \/>\n<a href=\"https:\/\/www.press.purdue.edu\/9781557535726\/\">Native Trees of the Midwest<\/a>, Purdue University Press<\/div>\n<div><a href=\"https:\/\/edustore.purdue.edu\/fnr-idnr-414.html\" target=\"_blank\" rel=\"noopener noreferrer\">Forest Improvement Handbook<\/a>, The Education Store<\/div>\n<div class=\"clearfix\">\n<p><a href=\"https:\/\/extension.entm.purdue.edu\/staff.html\" target=\"_blank\" rel=\"noopener\">Alicia Kelley<\/a>, Cooperative Agricultural Pest Survey <a href=\"https:\/\/caps.ceris.purdue.edu\/\" target=\"_blank\" rel=\"noopener\">(CAPS)<\/a> Coordinator<br \/>\nPurdue Extension &#8211; Entomology<\/p>\n<\/div>\n","protected":false},"excerpt":{"rendered":"<p>Purdue Landscape Report: Sawflies are frequent pests in the landscape that attack a wide variety of plants, from ornamental flowers to large trees. You might start to see them damaging plants around this time of year as the first generations hatch and begin to feed on foliage. They are often mistaken for caterpillars, which are [&hellip;]<\/p>\n","protected":false},"author":62,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[47,54,622],"tags":[60,65,1157,895,2045,408,72,495],"class_list":["post-33163","post","type-post","status-publish","format-standard","hentry","category-invasiveinsects","category-wildlife","category-woodlands","tag-forestry","tag-invasive-insects","tag-invasive-pests","tag-purdue-landscape-report","tag-sawflies","tag-trees","tag-wildlife","tag-woodlands","audience-for-enthusiasts","audience-for-homeowners","audience-for-landowners","audience-for-professionals"],"acf":[],"aioseo_notices":[],"publishpress_future_action":{"enabled":false,"date":"2026-04-16 10:23:40","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\/33163","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=33163"}],"version-history":[{"count":19,"href":"https:\/\/www.purdue.edu\/fnr\/extension\/wp-json\/wp\/v2\/posts\/33163\/revisions"}],"predecessor-version":[{"id":34365,"href":"https:\/\/www.purdue.edu\/fnr\/extension\/wp-json\/wp\/v2\/posts\/33163\/revisions\/34365"}],"wp:attachment":[{"href":"https:\/\/www.purdue.edu\/fnr\/extension\/wp-json\/wp\/v2\/media?parent=33163"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.purdue.edu\/fnr\/extension\/wp-json\/wp\/v2\/categories?post=33163"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.purdue.edu\/fnr\/extension\/wp-json\/wp\/v2\/tags?post=33163"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}