Metastrongylus apri

Metastrongylus apri	Contents	Rev 10/25/2025
Swine Lungworm	Classification	Biology and Ecology
	Morphology and Anatomy	Life Cycle
Return to Metastrongylus Menu		Ecosystem Functions and Services
	Distribution	Management
Return to Metastrongylidae Menu	Feeding	References
	Go to Nemaplex Main Menu	Go to Dictionary of Terminology

Metastrongylus apri (Gemlin, 1790) Railliet & Henry, 1907

Type species of the genus

    Synonyms

Metastrongylus elongatus

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Morphology and Anatomy:

Slender and white in colo
Six small lips or papillae surrounding the oral aperture



Males: 11-26 mm long x 120-255 um wide Spicules filiform 3.9-5.55.5 mm long and ending in a hook No gubernaculum. Well-developed genital cone.	Female: 28-60 mm long, 450 um wide. Vulva posterior, about 130 um from the tail; there is a prevulvar swelling with the vulva at the posterior end. Eggs with a rough, corrugated surface measuring 45-57 x 31-38 um containing L1 larvae when laid Ref: Marchiondo, 2020
Reported median body size for this species (Length mm; width micrometers; weight micrograms) - Click:

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Distribution:

Worldwide distribution, a lungworm infecting domestic pigs, wild boars, and peccary.

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Feeding:

A lungworm infecting domestic pigs, wild boars, and peccary. Occur in the small bronchi and bronchioles, particularly in the posterior lobes of the lung.

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Biology and Ecology:

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Life Cycle:

Swine as definitive hosts, earthworms (annelids)as intermediate hosts.

Eggs tolerant of cold temperatures; can survive in soil for over 1 year
Under optimal conditions, L1 hatch almost immediately from the egg and are ingested by the earthworm intermediate
Development to the L3 in the earthworm at temperatures between 22 and 26 C requires 10-30 days; the ensheathed L3 can survve up to 7 years.
Pigs ingest the earthworm with the L3 being released during digestion. L3 penetrate the wall of the intestine, pass to the mesenteric lymph nodes, and molt to the L4 which reach the lungs.
In the lungs, L4 molt to the adult stage.
Prepatent period in the definitive host is about4 weeks. (Marchiondo, 2020)