BugFinder Insects by State Spiders Butterflies & Moths Bees, Ants, & Wasps Beetles All Bugs Videos (YouTube)

Black Onion Fly (Tritoxa flexa)

Detailing the physical features, habits, territorial reach and other identifying qualities of the Black Onion Fly

Loading SVG image placeholder
Image Credit: Image copyright www.InsectIdentification.org; No Reproduction Permitted
Full-sized image of the Black-Onion-Fly Thumbnail image of the Black-Onion-Fly
Image Credit: Image copyright www.InsectIdentification.org; No Reproduction Permitted
Full-sized image #2 of the Black-Onion-Fly Thumbnail image #2 of the Black-Onion-Fly
Image Credit: Image copyright www.InsectIdentification.org; No Reproduction Permitted
Full-sized image #3 of the Black-Onion-Fly Thumbnail image #3 of the Black-Onion-Fly

Larvae of this fly breed and feed on onion bulbs underground, but generally not enough to decimate the harvest.

Updated: 02/10/2023; Authored By ; Content ©www.InsectIdentification.org
A kind of Picture-winged Fly, the Black Onion Fly has a distinctive pattern on its wings. Three white bands or stripes cross each black wing, which are actually transparent but appear white when the fly is standing on a light object. Two of the three stripes are prominent, but the third is closer to the body and may be more difficult to spot if the wings are closed. Its body is black and its eyes are dark.

The Black Onion Fly is small and often found in gardens, both vegetable and ornamental. The adult drinks flower nectar, but the larvae, or maggots, are plant eaters. Though not considered a serious pest, maggots feed on onion and garlic bulbs and use them as shelter during winter. Edible onions and ornamental onions are both susceptible. The damage to the harvest may be minimal, but rotating crops helps reduce the population in the following growing season.©InsectIdentification.org

Known Diet of the Black-Onion-Fly

onion; garlic
Note: The above text is EXCLUSIVE to the site www.InsectIdentification.org. It is the product of hours of research and work made possible with the help of contributors, educators, and topic specialists. If you happen upon this text anywhere else on the internet or in print, please let us know at InsectIdentification AT gmail DOT com so that we may take appropriate action against the offender / offending site and continue to protect this original work.

General Characteristics
Capability, Shape, Texture/Pattern, Benefits, Dangers
Flying insect icon
Garden pest insect icon
Pest insect icon
Striped or banded insect icon


Taxonomic Hierarchy
Species Breakdown
Kingdom: Animalia
  Phylum: Arthropoda
    Class: Insecta
      Order: Diptera
        Family: Ulidiidae
View More
          Genus: Tritoxa
View More
            Species: flexa
Identifying Information
Size, Colors, Features
Scientific Name: Tritoxa flexa
Category: Fly or Mosquito
Size (Adult; Length): 6mm to 12mm (0.23" to 0.47")
Colorwheel Graphic Colors: black; white
Descriptors: two white lines; all black; flying; garden pest; long nose; three white stripes

Relative Size Comparison
Typical Size Between 6mm (0.2in) and 12mm (0.5in)
Lo: 6mm
Md: 9mm
Hi: 12mm
Territorial Map*
U.S., Canada, and Mexico
State of Alabama graphic
State of Arizona graphic
State of Arkansas graphic
State of California graphic
State of Colorado graphic
State of Delware graphic
State of Florida graphic
State of Georgia graphic
State of Idaho graphic
State of Illinois graphic
State of Indiana graphic
State of Iowa graphic
State of Kansas graphic
State of Kentucky graphic
State of Louisiana graphic
State of Maine graphic
State of Maryland graphic
State of Michigan graphic
State of Minnesota graphic
State of Mississippi graphic
State of Missouri graphic
State of Montana graphic
State of Nebraska graphic
State of Nevada graphic
State of New England graphic
State of New Jersey graphic
State of New Mexico graphic
State of New York graphic
State of North Carolina graphic
State of North Dakota graphic
State of Ohio graphic
State of Oklahoma graphic
State of Oregon graphic
State of Pennsylvania graphic
State of South Carolina graphic
State of South Dakota graphic
State of Tennessee graphic
State of Texas graphic
State of Utah graphic
State of Virginia graphic
State of Washington graphic
State of West Virginia graphic
State of Wisconsin graphic
State of Wyoming graphic
Canadian territory of Alberta graphic
Canadian territory of British Columbia graphic
Canadian territory of Manitoba graphic
Canadian territory of New Brunswick graphic
Canadian territory of Newfoundland and Labrador graphic
Canadian territory of Ontario graphic
Canadian territory of Quebec graphic
Canadian territory of Saskatchewan graphic
Territory map graphic of the country of Mexico
Contiguous United States shape map layer graphic
Prince Edward Is.  
* MAP NOTES: The territorial heat map above showcases (in red) the states and territories of North America where the Black Onion Fly may be found (but is not limited to). This sort of data is useful when attempting to see concentrations of particular species across the continent as well as revealing possible migratory patterns over a species' given lifespan. Some insects are naturally confined by environment, weather, mating habits, food resources and the like while others see widespread expansion across most, or all, of North America. States/Territories shown above are a general indicator of areas inhabited by the Black Onion Fly. Insects generally go where they please, typically driven by diet, environmental changes, and / or mating habits.


Site Disclaimer  |  Privacy Policy  |  Cookies  |  Sitemap

Beetle Identification Butterfly Identification Caterpillar Identification Spider ID Fungal Infections on Insects Nursery Web Spider Official State Insects Termite Basics Insect Molting Process Bugs of Tennessee House Centipede.info

2023 www.InsectIdentification.org • Content ©2006-2023 InsectIdentification.org • All Rights Reserved. The InsectIdentification.org logo, its written content, and watermarked photographs/imagery are unique to this website (unless where indicated) and is protected by all applicable domestic and international intellectual property laws. Material presented throughout this website is for entertainment value and should not to be construed as usable for scientific research or medical advice (regarding bites, etc...).Please consult licensed, degreed professionals for such information. By submitting images to us (InsectIdentification.org) you acknowledge that you have read and understood our Site Disclaimer as it pertains to "User-Submitted Content". Images in JPG format are preferred with a minimum horizontal dimension of 1000px if possible. When emailing please include your location and the general estimated size of the specimen in question if possible. Please direct all inquiries and comments to insectidentification AT gmail.com.

©2023 www.InsectIdentification.org • All Rights Reserved • Content ©2006-2023 (17yrs)