{"id":232,"date":"2018-06-18T17:36:59","date_gmt":"2018-06-19T00:36:59","guid":{"rendered":"http:\/\/blogs.oregonstate.edu\/cutworm\/?p=232"},"modified":"2018-06-18T17:37:57","modified_gmt":"2018-06-19T00:37:57","slug":"striking-out","status":"publish","type":"post","link":"https:\/\/blogs.oregonstate.edu\/cutworm\/2018\/06\/18\/striking-out\/","title":{"rendered":"Striking out"},"content":{"rendered":"<p>As we endure the College World Series rain delay, let&#8217;s take time to learn about a different type of strike. (A segue stretch, I know)&#8230;<\/p>\n<p><em>Mamestra configurata<\/em> Walker, <strong>bertha armyworm<\/strong>, is native to North America and is a major pest of canola, so most published literature reports on damage and economic thresholds in <em>Brassica rapa<\/em> and <em>B. napus<\/em>, and some suggest that populations (in Canada) have gotten worse with the increasing acreage of rapeseed<sup>1<\/sup>.<\/p>\n<p>This species has been monitored for 20+ years via the <a href=\"http:\/\/agsci-labs.oregonstate.edu\/vegnet\/\">VegNet program<\/a>, and outbreaks in vegetable crops have been few and far between. However, as with any armyworm, <strong>scouting is KEY<\/strong> because when damage does occur, it happens quickly and usually on a large scale.<\/p>\n<p>Larvae feed above-ground, on foliage and fruit of hosts from over 40 different families. Some of the documented hosts include:<\/p>\n<ul>\n<li>Flax<\/li>\n<li>Alfalfa<\/li>\n<li>Fruit trees<\/li>\n<li>Sugarbeets<\/li>\n<li>Hops<\/li>\n<li>Mint<\/li>\n<li>Potatoes<\/li>\n<li>Weeds: especially lambsquarters, Canada thistle, and sow-thistle<\/li>\n<\/ul>\n<p>After group feeding on foliage as &#8216;baby&#8217; caterpillars, mid-stage larvae spin silk threads that help disperse them on the wind, a few meters within a field, and voracious feeding begins.<\/p>\n<p><strong>SCOUTING<\/strong>\u00a0for bertha armyworm involves <u>leaf pulling and visual scans<\/u>. As a scout crosses a field pulling and examining leaves, they should stop every ten leaves and scan for a plant or a small grouping of plants with a lot of holes in the leaves, then walk to that location and try to find larvae. <del><\/del><\/p>\n<p>These patchy, hard-to-find areas of damage are called <strong>armyworm \u201cstrikes\u201d<\/strong> [there it is].<\/p>\n<figure id=\"attachment_235\" class=\"wp-caption thumbnail aligncenter\" style=\"width: 205px;\">\n    <img data-recalc-dims=\"1\" loading=\"lazy\" decoding=\"async\" class=\"wp-image-235\" src=\"https:\/\/i0.wp.com\/blogs.oregonstate.edu\/cutworm\/files\/2018\/06\/BAW_wm.jpg?resize=205%2C172\" alt=\"\" width=\"205\" height=\"172\" srcset=\"https:\/\/i0.wp.com\/osu-wams-blogs-uploads.s3.amazonaws.com\/blogs.dir\/2721\/files\/2018\/06\/BAW_wm.jpg?w=589&amp;ssl=1 589w, https:\/\/i0.wp.com\/osu-wams-blogs-uploads.s3.amazonaws.com\/blogs.dir\/2721\/files\/2018\/06\/BAW_wm.jpg?resize=300%2C252&amp;ssl=1 300w\" sizes=\"auto, (max-width: 205px) 100vw, 205px\" \/>\n    <figcaption class=\"wp-caption-text\">Pheromone traps are used to monitor activity of adult bertha armyworm moths. The moths occur at low densities, but any detection of them in a trap is cause for prompt and careful field scouting.<\/figcaption>\n    <\/figure>\n<p>&nbsp;<\/p>\n<p><strong>MANAGEMENT<\/strong><br \/>\nNatural enemies (predators, parasitoids, viruses) probably exert heavy levels of control on bertha armyworm, otherwise we would see more frequent outbreaks.<\/p>\n<p>1. Dosdall, L.M. and B.J. Ulmer. 2004. Feeding, development, and oviposition of bertha armyworm on different host plant species. Environ. Ent. 33(3): p. 756-764.<\/p>\n<div>2. Lamb, R. J., W. J. Turnock, and H. N. Hayhoe. 1985. <span style=\"color: #000000\">Winter survival and outbreaks of bertha armyworm, <em>Mamestra configurata<\/em> on canola. Can.Entomol. 117: 727-736.<\/span><\/div>\n","protected":false},"excerpt":{"rendered":"<p>As we endure the College World Series rain delay, let&#8217;s take time to learn about a different type of strike. (A segue stretch, I know)&#8230; Mamestra configurata Walker, bertha armyworm, is native to North America and is a major pest of canola, so most published literature reports on damage and economic thresholds in Brassica rapa&hellip; <a href=\"https:\/\/blogs.oregonstate.edu\/cutworm\/2018\/06\/18\/striking-out\/\">Continue reading <span class=\"meta-nav\">&rarr;<\/span><\/a><\/p>\n","protected":false},"author":8003,"featured_media":0,"comment_status":"open","ping_status":"open","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_memberships_contains_paid_content":false,"footnotes":"","jetpack_publicize_message":"","jetpack_publicize_feature_enabled":true,"jetpack_social_post_already_shared":false,"jetpack_social_options":{"image_generator_settings":{"template":"highway","default_image_id":0,"font":"","enabled":false},"version":2},"jetpack_post_was_ever_published":false},"categories":[1],"tags":[1288041],"class_list":["post-232","post","type-post","status-publish","format-standard","hentry","category-uncategorized","tag-hostplants"],"jetpack_publicize_connections":[],"jetpack_featured_media_url":"","jetpack_sharing_enabled":true,"jetpack_shortlink":"https:\/\/wp.me\/paiW4b-3K","_links":{"self":[{"href":"https:\/\/blogs.oregonstate.edu\/cutworm\/wp-json\/wp\/v2\/posts\/232","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/blogs.oregonstate.edu\/cutworm\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/blogs.oregonstate.edu\/cutworm\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/blogs.oregonstate.edu\/cutworm\/wp-json\/wp\/v2\/users\/8003"}],"replies":[{"embeddable":true,"href":"https:\/\/blogs.oregonstate.edu\/cutworm\/wp-json\/wp\/v2\/comments?post=232"}],"version-history":[{"count":6,"href":"https:\/\/blogs.oregonstate.edu\/cutworm\/wp-json\/wp\/v2\/posts\/232\/revisions"}],"predecessor-version":[{"id":239,"href":"https:\/\/blogs.oregonstate.edu\/cutworm\/wp-json\/wp\/v2\/posts\/232\/revisions\/239"}],"wp:attachment":[{"href":"https:\/\/blogs.oregonstate.edu\/cutworm\/wp-json\/wp\/v2\/media?parent=232"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/blogs.oregonstate.edu\/cutworm\/wp-json\/wp\/v2\/categories?post=232"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/blogs.oregonstate.edu\/cutworm\/wp-json\/wp\/v2\/tags?post=232"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}