Hystricia abrupta

(Wiedemann, 1830)

Spiny-butt fly

Hystricia abrupta is a of bristle fly in the Tachinidae, commonly recognized by its spiny . This large tachinid fly is frequently found in western North America, where visit late summer and fall wildflowers for nectar. Like other tachinid flies, it is a , with larvae developing inside insects. It is often mistaken for similar large tachinids such as Adejeania vexatrix and Paradejeania rutilioides due to its robust, spiny appearance.

Hystricia abrupta by Mike Boone. Used under a CC BY-SA 2.5 license.Tachinid Fly. Adejeania sp.^ ( or Hystricia abrupta^ ) - Flickr - gailhampshire by gailhampshire from Cradley, Malvern, U.K. Used under a CC BY 2.0 license.Field book of insects (6244369942) by Lutz, Frank Eugene. Used under a Public domain license.

Pronunciation

How to pronounce Hystricia abrupta: //hɪˈstrɪʃiə əˈbrʌptə//

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Identification

Distinguished from Adejeania vexatrix by the absence of elongated, beak-like mouthpart palps; A. vexatrix is also slightly smaller, brighter in color, and shows a beak-like projection formed by elongated palps sheathing the mouthparts. Separated from Paradejeania rutilioides by being less robust and less spinier, with more subdued coloration; P. rutilioides is larger, more heavily spined, and tends toward more orange coloration. All three overlap in distribution and flower-visiting , requiring close examination of mouthparts and spine for reliable identification.

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Habitat

Forest and woodland in western North America. frequent flowering plants in late summer and fall.

Distribution

Western North America, ranging from British Columbia and Alberta south through California, Arizona, and New Mexico.

Seasonality

are active primarily in July and August; in more southerly portions of the range, activity may extend into September or October.

Host Associations

  • caterpillars - Larval development occurs inside caterpillar , though specific host have not been documented.

Behavior

are regular flower visitors, taking nectar from late summer and fall wildflowers. The exhibits declining abundance toward autumn in northern portions of its range.

Ecological Role

As a of caterpillars, contributes to natural of lepidopteran . flower-visiting may provide incidental pollination services.

Human Relevance

Beneficial insect through its role in controlling caterpillar . No known negative impacts on humans.

Similar Taxa

  • Adejeania vexatrixSimilar large size, spiny , and flower-visiting ; distinguished by A. vexatrix having elongated, beak-like palps, smaller size, brighter coloration, and declining autumn abundance.
  • Paradejeania rutilioidesSimilar robust, spiny appearance and shared ; distinguished by P. rutilioides being larger, more heavily spined, more orange in color, and active later in the season (August–October, with stragglers into November–December).
  • Macromya crocataStrongly resembles A. vexatrix and by extension H. abrupta; found in similar forested but lacks the beak-like palps of A. vexatrix.

More Details

Taxonomic notes

The Hystricia belongs to the tribe Polideini within the Tachininae. The was described by Wiedemann in 1830.

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Sources and further reading