Parasitylenchus		Contents		Rev: 05/18/2024
		Classification		Biology and Ecology
		Morphology and Anatomy		Life Cycle
Return to Parasitylenchus Menu				Ecosystem Functions and Services
		Distribution		Management
Return to Allantonematidae Menu		Feeding		References
		Go to Nemaplex Main Menu		Go to Dictionary of Terminology

Classification:

Chromadorea

Chromadoria

Rhabditida

Tylenchina/Hexatylina

Sphaerularioidea

 Parasitylenchidae or Allantonematidae

       Parasitylenchus Micoletzky, 1922

Type species of Parasitylenchus was designated by Micoletzky: Parasitylenchus dispar (Fuchs, 1914) Micoletzky, 1922

    Synonyms:
     

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Morphology and Anatomy:

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Distribution:

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Feeding:

Many species are parasites of beetles, Coleoptera; others of flies.

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Biology and Ecology:

Nematodes of the genus Parasitylenchus have a direct life cycle; there is no intermediate host. They complete two obligate parasitic generations in their hosts. Inseminated "motherworms" (adult females)  infect fly larvae and then produce larval nematodes (F1), which then mate inside the same host. It is their larval offspring (F2) that are then passed to mushrooms beds or other organic sources for psrasitism of healthy flies.  In the case of P. neoarcticus,the female fly host is sterilized by the nematode dmage to the gonads.

• In Parasitylenchus diplogenus, nematode parasitism of the flies damages both genital and intestinal tracts. Female gonads of the flies are almost completely destroyed by the emergence of the nematodes through the genital system.
• Larval worms pierce the thin peritoneal sheath surrounding the ovary and in time destroy it so that the ovarioles hang loose from their pedicels. Nematodes move between these loose ovarioles, pierce the epithelial sheath of the pedicels, and enter the lateral and the common oviducts. They occasionally pierce developing follicles, but rarely the basal follicles.
• Both the oviduct and the uterus are often tightly packed with nematodes and, in a few hosts, larvae were seen in the ducts that lead to the spermathecae. (Welch, 1958)

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Life Cycle:

According to Welch (1958):

• Parasitylenchus diplogenus has a life cycle of two sexual cycles.
• Larval hosts are penetrated by an inseminated female through the cuticle and into the haemocoele.
• The nematode develops in the host and at host pupation has become a gravid female.
• This female produces eggs that lie loose in the body cavity of the host and soon hatch into active larvae.
• The gravid female becomes sac-like and has no recognizable structure at the emergence of the adult fly.
• The larvae develop quickly, reach maturity, and mate, and the females begin egg-laying in the host haemocoele.
• The larvae leave female hosts by descending the oviduct to the vulva.
• The nematodes exit near material in which Drosophila larvae occur.

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Ecosystem Functions and Services:

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Management:

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References:

Welch, H.E. 1958. Taxonomy, life cycle, developmentand habits of two new species of Parasitylenchidae (Nematoda) parasitic in drosphilid flies. Contribution No. 3755, Entomology Division, Science Service, Department of Agriculture, Ottawa, Canada;

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Copyright © 1999 by Howard Ferris.
Revised: May 18, 2024.