{"id":6902,"date":"2009-04-14T10:58:56","date_gmt":"2009-04-14T15:58:56","guid":{"rendered":"https:\/\/uwm.edu\/field-station\/?p=6902"},"modified":"2017-06-19T19:52:21","modified_gmt":"2017-06-20T00:52:21","slug":"horsehair-worms","status":"publish","type":"post","link":"https:\/\/uwm.edu\/field-station\/bug-of-the-week\/horsehair-worms\/","title":{"rendered":"Horsehair Worms"},"content":{"rendered":"

Howdy, BugFans,<\/p>\n

Horsehair Worms<\/h3>\n

It\u2019s a good thing that the common usage of the term \u201cbug\u201d is so inexact, because once again we are stretching its boundaries to\/past the limits. Horsehair worms are in the phylum Nematomorpha. They\u2019re skinny and long; this individual was maybe five inches long, but some species attain one or two feet (well, they don\u2019t actually grow feet, but you know what the BugLady means). They have a hard chitinous covering which, says Ann Haven Morgan in her Field Book of Ponds and Streams<\/em>, stiffens them so that \u201cin their slow coiling and uncoiling they seem to be so much living wire.\u201d They come in opaque yellow to tan to brown to black colors. They\u2019re wiry and cylindrical, with little tapering at either end (unlike the nearby Nematodes).<\/p>\n

\"\"<\/a><\/p>\n

Adults live in damp-to-wet habitats from the tropics to the cold-temperate regions. Morgan goes on to say that they \u201clie like twisted roots or loose-coiled wire, on the bottom of brooks, springs, ponds, troughs, and rain-barrels.\u201d Horsehair worms tend to occur in clusters; Pennak, in Fresh-water Invertebrates of the United States<\/em>, describes them as \u201ca single writhing mass in the springtime.\u201d They look a bit like the snags the BugLady used to produce on her old casting reel.<\/p>\n

The adults do not eat. Pennak says that not only do they have a \u201cdegenerate and functionless\u201d digestive tract, they have \u201cno special circulatory, respiratory or excretory structures\u201d (and not much of a brain, either). Their muscle layer runs the long way, making them \u201cslowly undulating swimmers.\u201d But the simplicity of the adults is more than compensated for by their offspring.<\/p>\n

Mom lays more than a million (!!!) eggs in a gelatinous string, maybe 8\u201d long. The string breaks down into smaller pieces and disperses. When they hatch, the larvae soon attach to vegetation along the shoreline and form a protective cyst on the plant. They are inadvertently eaten (\u201cengulfed\u201d) by grazing grasshoppers, crickets and beetles (one source includes some mollusks and crustaceans all cold-blooded critters; these are not a public health issue). Once consumed, the cyst dissolves and Junior burrows into its host and begins dissolving and digesting the nearby tissue.<\/p>\n

When they mature, they need to exit their host\u2019s body, which doesn\u2019t sound like a benign process. It\u2019s best for Junior if the host is near water when this happens. One reputable source speculates that the maturation of Junior somehow causes the host to seek<\/em> water. Other references said that if the host is nowhere near water when Junior matures, \u201cc\u2019est la vie<\/em>\u201d—few hairworms that mature in the bodies of grasshoppers ever get back to water. If the host is near water when Junior is mature\/nearly mature, then Junior \u201cbreaks through\/burrows out of body wall and becomes free-living.\u201d Nature is careful of the species but careless of the individual. Nature has produced an exuberance of hairworms, and the system works often enough to keep the species going. An animal that produces that many eggs \u201cexpects\u201d a high mortality rate.<\/p>\n

A picture for your head: According to Morgan, a common species of hairworm reaches about a foot in length, and its larvae have been found in 2 species of cricket. If you\u2019re wondering how they do that, the BugLady is, too.<\/p>\n

These are also called \u201cGordian Worms,\u201d in honor of the Gordian Knot tied by King Gordius of Phrygia, a knot that only the future king of Asia would be able to untie (Alexander the Great \u201cthought outside the box\u201d and used his sword). The name \u201chorsehair worms\u201d is a nod to folk tales about horsehairs which say that \u201ca hair will turn to life if you leave it in water\/in the town watering trough overnight.\u201d (OK, the BugLady realizes that it\u2019s been a few years since there was a town watering trough.)<\/p>\n

 
\nThe BugLady<\/em><\/p>\n","protected":false},"excerpt":{"rendered":"

Horsehair Worms<\/strong> live in damp-to-wet habitats from the tropics to the cold-temperate regions. The adults do not eat. Mom lays more than a million (!!!) eggs in a gelatinous string, maybe 8\u201d long. The string breaks down into smaller pieces and disperses. When they hatch, the larvae soon attach to vegetation along the shoreline and form a protective cyst on the plant. Once consumed, the cyst dissolves and Junior burrows into its host and begins dissolving and digesting the nearby tissue.<\/p>\n","protected":false},"author":3993,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":"","uwm_wg_additional_authors":[]},"categories":[8],"tags":[],"class_list":["post-6902","post","type-post","status-publish","format-standard","hentry","category-bug-of-the-week"],"yoast_head":"\nField Station<\/title>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/uwm.edu\/field-station\/bug-of-the-week\/horsehair-worms\/\" \/>\n<meta property=\"og:locale\" content=\"en_US\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"Horsehair Worms\" \/>\n<meta property=\"og:description\" content=\"Horsehair Worms live in damp-to-wet habitats from the tropics to the cold-temperate regions. The adults do not eat. Mom lays more than a million (!!!) eggs in a gelatinous string, maybe 8\u201d long. The string breaks down into smaller pieces and disperses. When they hatch, the larvae soon attach to vegetation along the shoreline and form a protective cyst on the plant. Once consumed, the cyst dissolves and Junior burrows into its host and begins dissolving and digesting the nearby tissue.\" \/>\n<meta property=\"og:url\" content=\"https:\/\/uwm.edu\/field-station\/bug-of-the-week\/horsehair-worms\/\" \/>\n<meta property=\"og:site_name\" content=\"Field Station\" \/>\n<meta property=\"article:published_time\" content=\"2009-04-14T15:58:56+00:00\" \/>\n<meta property=\"article:modified_time\" content=\"2017-06-20T00:52:21+00:00\" \/>\n<meta property=\"og:image\" content=\"https:\/\/uwm.edu\/field-station\/wp-content\/uploads\/sites\/380\/2017\/02\/horsehairWorm.jpg\" \/>\n<meta name=\"twitter:card\" content=\"summary_large_image\" \/>\n<meta name=\"twitter:label1\" content=\"Written by\" \/>\n\t<meta name=\"twitter:data1\" content=\"\" \/>\n\t<meta name=\"twitter:label2\" content=\"Est. reading time\" \/>\n\t<meta name=\"twitter:data2\" content=\"3 minutes\" \/>\n<script type=\"application\/ld+json\" class=\"yoast-schema-graph\">{\"@context\":\"https:\\\/\\\/schema.org\",\"@graph\":[{\"@type\":\"Article\",\"@id\":\"https:\\\/\\\/uwm.edu\\\/field-station\\\/bug-of-the-week\\\/horsehair-worms\\\/#article\",\"isPartOf\":{\"@id\":\"https:\\\/\\\/uwm.edu\\\/field-station\\\/bug-of-the-week\\\/horsehair-worms\\\/\"},\"author\":{\"name\":\"\",\"@id\":\"\"},\"headline\":\"Horsehair Worms\",\"datePublished\":\"2009-04-14T15:58:56+00:00\",\"dateModified\":\"2017-06-20T00:52:21+00:00\",\"mainEntityOfPage\":{\"@id\":\"https:\\\/\\\/uwm.edu\\\/field-station\\\/bug-of-the-week\\\/horsehair-worms\\\/\"},\"wordCount\":652,\"image\":{\"@id\":\"https:\\\/\\\/uwm.edu\\\/field-station\\\/bug-of-the-week\\\/horsehair-worms\\\/#primaryimage\"},\"thumbnailUrl\":\"https:\\\/\\\/uwm.edu\\\/field-station\\\/wp-content\\\/uploads\\\/sites\\\/380\\\/2017\\\/02\\\/horsehairWorm.jpg\",\"articleSection\":[\"Bug of the Week\"],\"inLanguage\":\"en-US\"},{\"@type\":\"WebPage\",\"@id\":\"https:\\\/\\\/uwm.edu\\\/field-station\\\/bug-of-the-week\\\/horsehair-worms\\\/\",\"url\":\"https:\\\/\\\/uwm.edu\\\/field-station\\\/bug-of-the-week\\\/horsehair-worms\\\/\",\"name\":\"Horsehair Worms - Field Station\",\"isPartOf\":{\"@id\":\"https:\\\/\\\/uwm.edu\\\/field-station\\\/#website\"},\"primaryImageOfPage\":{\"@id\":\"https:\\\/\\\/uwm.edu\\\/field-station\\\/bug-of-the-week\\\/horsehair-worms\\\/#primaryimage\"},\"image\":{\"@id\":\"https:\\\/\\\/uwm.edu\\\/field-station\\\/bug-of-the-week\\\/horsehair-worms\\\/#primaryimage\"},\"thumbnailUrl\":\"https:\\\/\\\/uwm.edu\\\/field-station\\\/wp-content\\\/uploads\\\/sites\\\/380\\\/2017\\\/02\\\/horsehairWorm.jpg\",\"datePublished\":\"2009-04-14T15:58:56+00:00\",\"dateModified\":\"2017-06-20T00:52:21+00:00\",\"author\":{\"@id\":\"\"},\"breadcrumb\":{\"@id\":\"https:\\\/\\\/uwm.edu\\\/field-station\\\/bug-of-the-week\\\/horsehair-worms\\\/#breadcrumb\"},\"inLanguage\":\"en-US\",\"potentialAction\":[{\"@type\":\"ReadAction\",\"target\":[\"https:\\\/\\\/uwm.edu\\\/field-station\\\/bug-of-the-week\\\/horsehair-worms\\\/\"]}]},{\"@type\":\"ImageObject\",\"inLanguage\":\"en-US\",\"@id\":\"https:\\\/\\\/uwm.edu\\\/field-station\\\/bug-of-the-week\\\/horsehair-worms\\\/#primaryimage\",\"url\":\"https:\\\/\\\/uwm.edu\\\/field-station\\\/wp-content\\\/uploads\\\/sites\\\/380\\\/2017\\\/02\\\/horsehairWorm.jpg\",\"contentUrl\":\"https:\\\/\\\/uwm.edu\\\/field-station\\\/wp-content\\\/uploads\\\/sites\\\/380\\\/2017\\\/02\\\/horsehairWorm.jpg\"},{\"@type\":\"BreadcrumbList\",\"@id\":\"https:\\\/\\\/uwm.edu\\\/field-station\\\/bug-of-the-week\\\/horsehair-worms\\\/#breadcrumb\",\"itemListElement\":[{\"@type\":\"ListItem\",\"position\":1,\"name\":\"Home\",\"item\":\"https:\\\/\\\/uwm.edu\\\/field-station\\\/\"},{\"@type\":\"ListItem\",\"position\":2,\"name\":\"Bug of the Week\",\"item\":\"https:\\\/\\\/uwm.edu\\\/field-station\\\/category\\\/bug-of-the-week\\\/\"},{\"@type\":\"ListItem\",\"position\":3,\"name\":\"Horsehair Worms\"}]},{\"@type\":\"WebSite\",\"@id\":\"https:\\\/\\\/uwm.edu\\\/field-station\\\/#website\",\"url\":\"https:\\\/\\\/uwm.edu\\\/field-station\\\/\",\"name\":\"Field Station\",\"description\":\"UW-Milwaukee\",\"potentialAction\":[{\"@type\":\"SearchAction\",\"target\":{\"@type\":\"EntryPoint\",\"urlTemplate\":\"https:\\\/\\\/uwm.edu\\\/field-station\\\/?s={search_term_string}\"},\"query-input\":{\"@type\":\"PropertyValueSpecification\",\"valueRequired\":true,\"valueName\":\"search_term_string\"}}],\"inLanguage\":\"en-US\"},{\"@type\":\"Person\",\"@id\":\"\"}]}<\/script>\n<!-- \/ Yoast SEO Premium plugin. -->","yoast_head_json":{"title":"Field Station","robots":{"index":"index","follow":"follow","max-snippet":"max-snippet:-1","max-image-preview":"max-image-preview:large","max-video-preview":"max-video-preview:-1"},"canonical":"https:\/\/uwm.edu\/field-station\/bug-of-the-week\/horsehair-worms\/","og_locale":"en_US","og_type":"article","og_title":"Horsehair Worms","og_description":"Horsehair Worms live in damp-to-wet habitats from the tropics to the cold-temperate regions. The adults do not eat. Mom lays more than a million (!!!) eggs in a gelatinous string, maybe 8\u201d long. The string breaks down into smaller pieces and disperses. When they hatch, the larvae soon attach to vegetation along the shoreline and form a protective cyst on the plant. Once consumed, the cyst dissolves and Junior burrows into its host and begins dissolving and digesting the nearby tissue.","og_url":"https:\/\/uwm.edu\/field-station\/bug-of-the-week\/horsehair-worms\/","og_site_name":"Field Station","article_published_time":"2009-04-14T15:58:56+00:00","article_modified_time":"2017-06-20T00:52:21+00:00","og_image":[{"url":"https:\/\/uwm.edu\/field-station\/wp-content\/uploads\/sites\/380\/2017\/02\/horsehairWorm.jpg","type":"","width":"","height":""}],"twitter_card":"summary_large_image","twitter_misc":{"Written by":"","Est. reading time":"3 minutes"},"schema":{"@context":"https:\/\/schema.org","@graph":[{"@type":"Article","@id":"https:\/\/uwm.edu\/field-station\/bug-of-the-week\/horsehair-worms\/#article","isPartOf":{"@id":"https:\/\/uwm.edu\/field-station\/bug-of-the-week\/horsehair-worms\/"},"author":{"name":"","@id":""},"headline":"Horsehair Worms","datePublished":"2009-04-14T15:58:56+00:00","dateModified":"2017-06-20T00:52:21+00:00","mainEntityOfPage":{"@id":"https:\/\/uwm.edu\/field-station\/bug-of-the-week\/horsehair-worms\/"},"wordCount":652,"image":{"@id":"https:\/\/uwm.edu\/field-station\/bug-of-the-week\/horsehair-worms\/#primaryimage"},"thumbnailUrl":"https:\/\/uwm.edu\/field-station\/wp-content\/uploads\/sites\/380\/2017\/02\/horsehairWorm.jpg","articleSection":["Bug of the Week"],"inLanguage":"en-US"},{"@type":"WebPage","@id":"https:\/\/uwm.edu\/field-station\/bug-of-the-week\/horsehair-worms\/","url":"https:\/\/uwm.edu\/field-station\/bug-of-the-week\/horsehair-worms\/","name":"Horsehair Worms - Field Station","isPartOf":{"@id":"https:\/\/uwm.edu\/field-station\/#website"},"primaryImageOfPage":{"@id":"https:\/\/uwm.edu\/field-station\/bug-of-the-week\/horsehair-worms\/#primaryimage"},"image":{"@id":"https:\/\/uwm.edu\/field-station\/bug-of-the-week\/horsehair-worms\/#primaryimage"},"thumbnailUrl":"https:\/\/uwm.edu\/field-station\/wp-content\/uploads\/sites\/380\/2017\/02\/horsehairWorm.jpg","datePublished":"2009-04-14T15:58:56+00:00","dateModified":"2017-06-20T00:52:21+00:00","author":{"@id":""},"breadcrumb":{"@id":"https:\/\/uwm.edu\/field-station\/bug-of-the-week\/horsehair-worms\/#breadcrumb"},"inLanguage":"en-US","potentialAction":[{"@type":"ReadAction","target":["https:\/\/uwm.edu\/field-station\/bug-of-the-week\/horsehair-worms\/"]}]},{"@type":"ImageObject","inLanguage":"en-US","@id":"https:\/\/uwm.edu\/field-station\/bug-of-the-week\/horsehair-worms\/#primaryimage","url":"https:\/\/uwm.edu\/field-station\/wp-content\/uploads\/sites\/380\/2017\/02\/horsehairWorm.jpg","contentUrl":"https:\/\/uwm.edu\/field-station\/wp-content\/uploads\/sites\/380\/2017\/02\/horsehairWorm.jpg"},{"@type":"BreadcrumbList","@id":"https:\/\/uwm.edu\/field-station\/bug-of-the-week\/horsehair-worms\/#breadcrumb","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https:\/\/uwm.edu\/field-station\/"},{"@type":"ListItem","position":2,"name":"Bug of the Week","item":"https:\/\/uwm.edu\/field-station\/category\/bug-of-the-week\/"},{"@type":"ListItem","position":3,"name":"Horsehair Worms"}]},{"@type":"WebSite","@id":"https:\/\/uwm.edu\/field-station\/#website","url":"https:\/\/uwm.edu\/field-station\/","name":"Field Station","description":"UW-Milwaukee","potentialAction":[{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https:\/\/uwm.edu\/field-station\/?s={search_term_string}"},"query-input":{"@type":"PropertyValueSpecification","valueRequired":true,"valueName":"search_term_string"}}],"inLanguage":"en-US"},{"@type":"Person","@id":""}]}},"acf":[],"meta_fields":{"_edit_lock":["1497919813:28"],"_edit_last":["28"],"_yoast_wpseo_content_score":["30"],"_yoast_wpseo_primary_category":["8"],"_wp_old_slug":["horsehair-worms-phylum-nematomorpha"],"_uwm_wg_content_review_log":["a:1:{i:0;a:5:{s:11:\"reviewer_id\";i:0;s:6:\"status\";s:5:\"reset\";s:10:\"entry_date\";s:19:\"2026-03-01 02:10:52\";s:16:\"priority_content\";s:0:\"\";s:4:\"note\";s:43:\"Content review reset at start of new cycle.\";}}"]},"publishpress_future_action":{"enabled":false,"date":"2026-04-26 08:47:56","action":"change-status","newStatus":"draft","terms":[],"taxonomy":"category","extraData":[]},"publishpress_future_workflow_manual_trigger":{"enabledWorkflows":[]},"_links":{"self":[{"href":"https:\/\/uwm.edu\/field-station\/wp-json\/wp\/v2\/posts\/6902","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/uwm.edu\/field-station\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/uwm.edu\/field-station\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/uwm.edu\/field-station\/wp-json\/wp\/v2\/users\/3993"}],"replies":[{"embeddable":true,"href":"https:\/\/uwm.edu\/field-station\/wp-json\/wp\/v2\/comments?post=6902"}],"version-history":[{"count":4,"href":"https:\/\/uwm.edu\/field-station\/wp-json\/wp\/v2\/posts\/6902\/revisions"}],"predecessor-version":[{"id":8398,"href":"https:\/\/uwm.edu\/field-station\/wp-json\/wp\/v2\/posts\/6902\/revisions\/8398"}],"wp:attachment":[{"href":"https:\/\/uwm.edu\/field-station\/wp-json\/wp\/v2\/media?parent=6902"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/uwm.edu\/field-station\/wp-json\/wp\/v2\/categories?post=6902"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/uwm.edu\/field-station\/wp-json\/wp\/v2\/tags?post=6902"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}