{"id":4412,"date":"2011-01-27T10:01:06","date_gmt":"2011-01-27T15:01:06","guid":{"rendered":"http:\/\/extension.umaine.edu\/ipm\/"},"modified":"2023-02-02T17:36:26","modified_gmt":"2023-02-02T22:36:26","slug":"5031e","status":"publish","type":"page","link":"https:\/\/extension.umaine.edu\/ipm\/ipddl\/publications\/5031e\/","title":{"rendered":"Onion Maggot"},"content":{"rendered":"

\n \n \"Print\n <\/a>\n <\/div><\/h3>\n

Pest Management Fact Sheet #5031<\/h3>\n
\"Onion
Onion Maggot larva, pupa, and adult<\/em><\/figcaption><\/figure>\n

James F. Dill, Pest Management Specialist
\nClay A. Kirby, Insect Diagnostician<\/em><\/p>\n

For information about UMaine Extension programs and resources, visit extension.umaine.edu<\/a>.
\nFind more of our publications and books at extension.umaine.edu\/publications\/<\/a>.<\/strong>
\n<\/span><\/strong><\/p>\n

Description & Biology<\/h3>\n

The onion maggot (Delia antiqua<\/em>) is one of the most destructive insect pest of onions and related plants. Injured seedlings wilt and die. Larger bulbs may survive some injury, but are often poor keepers. Once onion maggots infest an area, they tend to be a problem every year. White onion varieties are more susceptible to attack than other varieties.<\/p>\n

Onion flies and maggots are very similar to the seedcorn maggot, Delia platura. <\/em>The grayish brown adult is less than a 1\/3″ and lacks the cabbage maggot\u2019s three dark thoracic stripes. These flies will generally stay hidden. When mature, the whitish maggots are about 1\/4″ long.<\/p>\n

The onion maggot overwinters in the pupal stage under debris in or near the soil surface. In about the third week of May, when onions are up or planted, the flies emerge to lay their eggs near the onion plants. In less than a week, the eggs hatch.<\/p>\n

The maggots feed for two to three weeks and then pupate. In about two weeks, the second-generation adults emerge from the pupal stage. Cool, wet weather favors development of three generations per year. A complete life cycle takes 45 to 65 days.<\/p>\n

Stunted or wilting onion plants are the first signs of onion maggot damage. At this time, you may find the maggots in putrid, decomposing onion plants. Light infestations may not kill onions, but may make them more susceptible to rots. Onions of all sizes may be attacked, especially in the fall, when cooler weather favors the maggot’s activity. Damaged onions are not marketable and will rot in storage causing other onions to rot.<\/p>\n

Management<\/h3>\n

The onion maggot has many natural enemies such as ground beetles, birds, parasitic wasps, nematodes and a fungus that is most effective in cool, wet weather. There seems to be no resistant varieties at this time except for a Japanese bunching onion that, at times, shows resistance or at least tolerance.<\/p>\n

Rotation as a method of maggot control is not practical for the home gardener, but controlling wild onions should help. Volunteer onions and chives may be a source of infestations. The onions should be removed and the wastes burned and not plowed into the soil. Highly organic soil may be more attractive to the flies. Barriers (such as floating row covers) may help protect onions from the adult fly.<\/p>\n

Controlling the spring infestation is most important because small or new plants are most easily damaged. Killing flies or maggots in the spring helps to lower their populations in the fall.<\/p>\n

\n

When Using Pesticides<\/strong><\/span><\/p>\n

ALWAYS FOLLOW LABEL DIRECTIONS!<\/strong><\/span><\/h3>\n

Pest Management Unit
\nCooperative Extension Diagnostic and Research Laboratory
\n17 Godfrey Drive, Orono, ME 04473
\n1.800.287.0279 (in Maine)<\/p>\n

\n

Information in this publication is provided purely for educational purposes. No responsibility is assumed for any problems associated with the use of products or services mentioned. No endorsement of products or companies is intended, nor is criticism of unnamed products or companies implied.<\/em><\/p>\n

\u00a9 2016, 2018, 2020 | Reviewed: 2023<\/p>\n

Call 800.287.0274 (in Maine), or 207.581.3188, for information on publications and program offerings from University of Maine Cooperative Extension, or visit extension.umaine.edu<\/a>.<\/strong><\/p>\n

In complying with the letter and spirit of applicable laws and pursuing its own goals of diversity, the University of Maine System does not discriminate on the grounds of race, color, religion, sex, sexual orientation, transgender status, gender, gender identity or expression, ethnicity, national origin, citizenship status, familial status, ancestry, age, disability physical or mental, genetic information, or veterans or military status in employment, education, and all other programs and activities. The University provides reasonable accommodations to qualified individuals with disabilities upon request. The following person has been designated to handle inquiries regarding non-discrimination policies: Director of Equal Opportunity, 101 Boudreau Hall, University of Maine, Orono, ME 04469-5754, 207.581.1226, TTY 711 (Maine Relay System).<\/em><\/p>\n","protected":false},"excerpt":{"rendered":"

Pest Management Fact Sheet #5031 James F. Dill, Pest Management Specialist Clay A. Kirby, Insect Diagnostician For information about UMaine Extension programs and resources, visit extension.umaine.edu. Find more of our publications and books at extension.umaine.edu\/publications\/. Description & Biology The onion maggot (Delia antiqua) is one of the most destructive insect pest of onions and related […]<\/p>\n","protected":false},"author":3,"featured_media":0,"parent":3249,"menu_order":41,"comment_status":"closed","ping_status":"closed","template":"","meta":{"_kad_blocks_custom_css":"","_kad_blocks_head_custom_js":"","_kad_blocks_body_custom_js":"","_kad_blocks_footer_custom_js":"","_monsterinsights_skip_tracking":false,"_monsterinsights_sitenote_active":false,"_monsterinsights_sitenote_note":"","_monsterinsights_sitenote_category":0,"footnotes":""},"class_list":["post-4412","page","type-page","status-publish","hentry"],"yoast_head":"\nOnion Maggot - Cooperative Extension: Insect Pests, Ticks and Plant Diseases - University of Maine Cooperative Extension<\/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:\/\/extension.umaine.edu\/ipm\/ipddl\/publications\/5031e\/\" \/>\n<meta property=\"og:locale\" content=\"en_US\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"Onion Maggot - Cooperative Extension: Insect Pests, Ticks and Plant Diseases - University of Maine Cooperative Extension\" \/>\n<meta property=\"og:description\" content=\"Pest Management Fact Sheet #5031 James F. Dill, Pest Management Specialist Clay A. Kirby, Insect Diagnostician For information about UMaine Extension programs and resources, visit extension.umaine.edu. Find more of our publications and books at extension.umaine.edu\/publications\/. Description & Biology The onion maggot (Delia antiqua) is one of the most destructive insect pest of onions and related […]\" \/>\n<meta property=\"og:url\" content=\"https:\/\/extension.umaine.edu\/ipm\/ipddl\/publications\/5031e\/\" \/>\n<meta property=\"og:site_name\" content=\"Cooperative Extension: Insect Pests, Ticks and Plant Diseases\" \/>\n<meta property=\"article:modified_time\" content=\"2023-02-02T22:36:26+00:00\" \/>\n<meta property=\"og:image\" content=\"https:\/\/extension.umaine.edu\/ipm\/wp-content\/uploads\/sites\/44\/2011\/01\/ONION.jpg\" \/>\n<meta name=\"twitter:card\" content=\"summary_large_image\" \/>\n<meta name=\"twitter:label1\" content=\"Est. reading time\" \/>\n\t<meta name=\"twitter:data1\" content=\"3 minutes\" \/>\n<script type=\"application\/ld+json\" class=\"yoast-schema-graph\">{\"@context\":\"https:\/\/schema.org\",\"@graph\":[{\"@type\":\"WebPage\",\"@id\":\"https:\/\/extension.umaine.edu\/ipm\/ipddl\/publications\/5031e\/\",\"url\":\"https:\/\/extension.umaine.edu\/ipm\/ipddl\/publications\/5031e\/\",\"name\":\"Onion Maggot - Cooperative Extension: Insect Pests, Ticks and Plant Diseases - University of Maine Cooperative Extension\",\"isPartOf\":{\"@id\":\"https:\/\/extension.umaine.edu\/ipm\/#website\"},\"primaryImageOfPage\":{\"@id\":\"https:\/\/extension.umaine.edu\/ipm\/ipddl\/publications\/5031e\/#primaryimage\"},\"image\":{\"@id\":\"https:\/\/extension.umaine.edu\/ipm\/ipddl\/publications\/5031e\/#primaryimage\"},\"thumbnailUrl\":\"https:\/\/extension.umaine.edu\/ipm\/wp-content\/uploads\/sites\/44\/2011\/01\/ONION.jpg\",\"datePublished\":\"2011-01-27T15:01:06+00:00\",\"dateModified\":\"2023-02-02T22:36:26+00:00\",\"breadcrumb\":{\"@id\":\"https:\/\/extension.umaine.edu\/ipm\/ipddl\/publications\/5031e\/#breadcrumb\"},\"inLanguage\":\"en-US\",\"potentialAction\":[{\"@type\":\"ReadAction\",\"target\":[\"https:\/\/extension.umaine.edu\/ipm\/ipddl\/publications\/5031e\/\"]}]},{\"@type\":\"ImageObject\",\"inLanguage\":\"en-US\",\"@id\":\"https:\/\/extension.umaine.edu\/ipm\/ipddl\/publications\/5031e\/#primaryimage\",\"url\":\"https:\/\/extension.umaine.edu\/ipm\/wp-content\/uploads\/sites\/44\/2011\/01\/ONION.jpg\",\"contentUrl\":\"https:\/\/extension.umaine.edu\/ipm\/wp-content\/uploads\/sites\/44\/2011\/01\/ONION.jpg\",\"width\":208,\"height\":135,\"caption\":\"Onion Maggot larva, pupa, and adult\"},{\"@type\":\"BreadcrumbList\",\"@id\":\"https:\/\/extension.umaine.edu\/ipm\/ipddl\/publications\/5031e\/#breadcrumb\",\"itemListElement\":[{\"@type\":\"ListItem\",\"position\":1,\"name\":\"Home\",\"item\":\"https:\/\/extension.umaine.edu\/ipm\/\"},{\"@type\":\"ListItem\",\"position\":2,\"name\":\"Insect and Plant Disease Diagnostic Labs\",\"item\":\"https:\/\/extension.umaine.edu\/ipm\/ipddl\/\"},{\"@type\":\"ListItem\",\"position\":3,\"name\":\"Insect, Tick, and Plant Disease Fact Sheet Publications\",\"item\":\"https:\/\/extension.umaine.edu\/ipm\/ipddl\/publications\/\"},{\"@type\":\"ListItem\",\"position\":4,\"name\":\"Onion Maggot\"}]},{\"@type\":\"WebSite\",\"@id\":\"https:\/\/extension.umaine.edu\/ipm\/#website\",\"url\":\"https:\/\/extension.umaine.edu\/ipm\/\",\"name\":\"Cooperative Extension: Insect Pests, Ticks and Plant Diseases\",\"description\":\"Information you can use. Research you can trust.\",\"potentialAction\":[{\"@type\":\"SearchAction\",\"target\":{\"@type\":\"EntryPoint\",\"urlTemplate\":\"https:\/\/extension.umaine.edu\/ipm\/?s={search_term_string}\"},\"query-input\":{\"@type\":\"PropertyValueSpecification\",\"valueRequired\":true,\"valueName\":\"search_term_string\"}}],\"inLanguage\":\"en-US\"}]}<\/script>\n<!-- \/ Yoast SEO plugin. -->","yoast_head_json":{"title":"Onion Maggot - Cooperative Extension: Insect Pests, Ticks and Plant Diseases - University of Maine Cooperative Extension","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:\/\/extension.umaine.edu\/ipm\/ipddl\/publications\/5031e\/","og_locale":"en_US","og_type":"article","og_title":"Onion Maggot - Cooperative Extension: Insect Pests, Ticks and Plant Diseases - University of Maine Cooperative Extension","og_description":"Pest Management Fact Sheet #5031 James F. Dill, Pest Management Specialist Clay A. Kirby, Insect Diagnostician For information about UMaine Extension programs and resources, visit extension.umaine.edu. Find more of our publications and books at extension.umaine.edu\/publications\/. Description & Biology The onion maggot (Delia antiqua) is one of the most destructive insect pest of onions and related […]","og_url":"https:\/\/extension.umaine.edu\/ipm\/ipddl\/publications\/5031e\/","og_site_name":"Cooperative Extension: Insect Pests, Ticks and Plant Diseases","article_modified_time":"2023-02-02T22:36:26+00:00","og_image":[{"url":"https:\/\/extension.umaine.edu\/ipm\/wp-content\/uploads\/sites\/44\/2011\/01\/ONION.jpg","type":"","width":"","height":""}],"twitter_card":"summary_large_image","twitter_misc":{"Est. reading time":"3 minutes"},"schema":{"@context":"https:\/\/schema.org","@graph":[{"@type":"WebPage","@id":"https:\/\/extension.umaine.edu\/ipm\/ipddl\/publications\/5031e\/","url":"https:\/\/extension.umaine.edu\/ipm\/ipddl\/publications\/5031e\/","name":"Onion Maggot - Cooperative Extension: Insect Pests, Ticks and Plant Diseases - University of Maine Cooperative Extension","isPartOf":{"@id":"https:\/\/extension.umaine.edu\/ipm\/#website"},"primaryImageOfPage":{"@id":"https:\/\/extension.umaine.edu\/ipm\/ipddl\/publications\/5031e\/#primaryimage"},"image":{"@id":"https:\/\/extension.umaine.edu\/ipm\/ipddl\/publications\/5031e\/#primaryimage"},"thumbnailUrl":"https:\/\/extension.umaine.edu\/ipm\/wp-content\/uploads\/sites\/44\/2011\/01\/ONION.jpg","datePublished":"2011-01-27T15:01:06+00:00","dateModified":"2023-02-02T22:36:26+00:00","breadcrumb":{"@id":"https:\/\/extension.umaine.edu\/ipm\/ipddl\/publications\/5031e\/#breadcrumb"},"inLanguage":"en-US","potentialAction":[{"@type":"ReadAction","target":["https:\/\/extension.umaine.edu\/ipm\/ipddl\/publications\/5031e\/"]}]},{"@type":"ImageObject","inLanguage":"en-US","@id":"https:\/\/extension.umaine.edu\/ipm\/ipddl\/publications\/5031e\/#primaryimage","url":"https:\/\/extension.umaine.edu\/ipm\/wp-content\/uploads\/sites\/44\/2011\/01\/ONION.jpg","contentUrl":"https:\/\/extension.umaine.edu\/ipm\/wp-content\/uploads\/sites\/44\/2011\/01\/ONION.jpg","width":208,"height":135,"caption":"Onion Maggot larva, pupa, and adult"},{"@type":"BreadcrumbList","@id":"https:\/\/extension.umaine.edu\/ipm\/ipddl\/publications\/5031e\/#breadcrumb","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https:\/\/extension.umaine.edu\/ipm\/"},{"@type":"ListItem","position":2,"name":"Insect and Plant Disease Diagnostic Labs","item":"https:\/\/extension.umaine.edu\/ipm\/ipddl\/"},{"@type":"ListItem","position":3,"name":"Insect, Tick, and Plant Disease Fact Sheet Publications","item":"https:\/\/extension.umaine.edu\/ipm\/ipddl\/publications\/"},{"@type":"ListItem","position":4,"name":"Onion Maggot"}]},{"@type":"WebSite","@id":"https:\/\/extension.umaine.edu\/ipm\/#website","url":"https:\/\/extension.umaine.edu\/ipm\/","name":"Cooperative Extension: Insect Pests, Ticks and Plant Diseases","description":"Information you can use. Research you can trust.","potentialAction":[{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https:\/\/extension.umaine.edu\/ipm\/?s={search_term_string}"},"query-input":{"@type":"PropertyValueSpecification","valueRequired":true,"valueName":"search_term_string"}}],"inLanguage":"en-US"}]}},"taxonomy_info":[],"featured_image_src_large":false,"author_info":{"display_name":"","author_link":"https:\/\/extension.umaine.edu\/ipm\/author\/"},"comment_info":0,"_links":{"self":[{"href":"https:\/\/extension.umaine.edu\/ipm\/wp-json\/wp\/v2\/pages\/4412","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/extension.umaine.edu\/ipm\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/extension.umaine.edu\/ipm\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/extension.umaine.edu\/ipm\/wp-json\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/extension.umaine.edu\/ipm\/wp-json\/wp\/v2\/comments?post=4412"}],"version-history":[{"count":13,"href":"https:\/\/extension.umaine.edu\/ipm\/wp-json\/wp\/v2\/pages\/4412\/revisions"}],"predecessor-version":[{"id":27328,"href":"https:\/\/extension.umaine.edu\/ipm\/wp-json\/wp\/v2\/pages\/4412\/revisions\/27328"}],"up":[{"embeddable":true,"href":"https:\/\/extension.umaine.edu\/ipm\/wp-json\/wp\/v2\/pages\/3249"}],"wp:attachment":[{"href":"https:\/\/extension.umaine.edu\/ipm\/wp-json\/wp\/v2\/media?parent=4412"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}