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Banded Horntail (Urocerus gigas flavicornis)

Detailing the identifying qualities of the Banded Horntail, including physical features and territorial reach.

 Updated: 2/2/2018; Authored By Staff Writer; Content ¬©

  Banded Horntail  
Picture of Banded-Horntail
Picture of Banded-Horntail

A Banded Horntail seems like its a mean wasp with a long, nasty stinger, but its looks don't do its passive nature justice.

Though adults appear menacing to humans, Banded Horntails are not aggressive and do not sting nor bite. Long, tubular bodies have prominent yellow bands at the end of the abdomen. The alarm coloration is often the precursor to unnecessary panic thanks to the stiff 'horntail' at the tip of the abdomen. Females have what appear to be two 'stingers'. The longer, syringe-like one is actually an ovipositor. This strong organ is used to punch holes into hard tree trunks and then inject eggs into the wood. The hope is that burying the eggs deeper into wood will offer them more protection. The larvae of Banded Horntails have enemies. They are sought out and eaten by the growing larvae of other parasitic wasps that were laid on the same tree trunk. If the Horntail larvae survive the hunt, they will feed on the interior wood of the tree, tunneling through vascular tissue, and eventually emerge as adults.

Males have been seen clustering together at high ground while they wait for females to come and mate with them. This behavior is called "hilltopping". Once they have mated, adult females work tirelessly, boring as many holes and laying as many eggs as they can before dying. Adults only live for about 3 to 4 weeks. In that short life span, a female can lay over 300 eggs, each in their own hole. The whole life of a Banded Horntail, from larva to adult, can last 3 years.

Because this species prefers conifer trees like pine, it is not uncommon to see young adults indoors as they emerge from wood that was harvested years prior and used to build things (like furniture) while they were still developing larvae. The tunneling can impact the beauty of the wood, affecting its usability, so Horntails are generally considered a nuisance in the lumber industry.

Banded Horntail Information

Category: Bee, Ant, Wasp and Similar
Common Name: Banded Horntail
Scientific Name: Urocerus gigas flavicornis
Other Name(s): Greater Horntail

Taxonomy Hierarchy

 Arrow graphic Kingdom: Animalia
  Arrow graphic Phylum: Arthropoda
   Arrow graphic Class: Insecta
    Arrow graphic Order: Acari
     Arrow graphic Family: Siricidae
      Arrow graphic Genus: Urocerus
       Arrow graphic Species: gigas flavicornis

Size, Identifying Tags and Territorial Reach

Size (Adult, Length): Size (Adult, Length): 12 mm to 40 mm (0.468 inches to 1.56 inches)
Identifying Colors: black, yellow, brown
Additional Descriptors: stinger, band, stripe, tail, spine, flying, harmless, wasp, clusters, woodwasp

North American Territorial Reach (Though Not Limited To): Alaska; California; Colorado; Idaho; Montana; Nevada; New Mexico; North Dakota; Oklahoma; Oregon; South Dakota; Texas; Utah; Washington; Wyoming; Alberta; British Columbia; Manitoba; New Brunswick; Newfoundland and Labrador; Nova Scotia; Ontario; Prince Edward Island; Quebec; Saskatchewan

A Note About Territorial Reach: Keep in mind that an insect's reach is not limited by lines drawn on a map and therefore species may appear in areas, regions and/or states beyond those listed above. Insects are driven by environmental factors, food supplies and mating patterns and do not nescessarily work within hard-and-fast territorial lines like we humans do.

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