Draschia megastoma		Contents		Rev 10/28/2025
Equine Stomach Worm		Classification		Hosts
		Morphology and Anatomy		Life Cycle
Return to Draschia Menu		Economic Importance		Damage
		Distribution		Management
Return to Habronematidae Menu		Feeding		References
		Go to Nemaplex HomePage		Go to Dictionary of Terminology

Classification:

Chromadorea

  Chromadoria

   Rhabditida

Spirurina

              Habronematoidea

               Habronematidae

           Draschia megastoma (Rudolphi, 1819) Chitweood & Wehr, 1934

Type species of the genus

Synonyms:

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Morphology and Anatomy:

• Head with a funnel-shaped buccal cavity and separated from the rest of the body by a constriction.

Females:

•  Length 10-13 mm
• Tail conical.280 um long
• Eggs very long , 330-350 x 8 um.

Males:

• Length 7-10 mm.
• Spicules unequal length (left cylindrical\ , 460 um long; right flat, grooved, 280 um long)

Ref: Marchiondo and Cruthers, 2020

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Distribution:

Worldwide

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Feeding:

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Biology and Ecology:

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Life Cycle:

Life cycle involves an intermediate host.

•  L1 is ingested from fecal material by fly larvae (Musca and Pseudopyrellia species) and develop to L2 in the Malpighian tubule causing large nodules.
• The L2 break out of the nodules and develop to the infective L3 that migrate to the fly’s labium.
• The L3 are passed out and deposited around the mouth, lips, and nose of the horse; they are swallowed, and develop in the stomach.
• Eggs and L1 are deposited in feces.
• The prepatent period of D. megastoma is about 2 months (Marchiondo and Cruthers, 2020)

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Ecosystem Functions and Services:

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Management:

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References:

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Copyright 1999 by Howard Ferris.
Revised: October 28, 2025.