Deladenus		Contents		Rev: 02/23/2024
		Classification		Biology and Ecology
		Morphology and Anatomy		Life Cycle
Return to Deladenus Menu				Ecosystem Functions and Services
		Distribution		Management
Return to Neotylenchidae Menu		Feeding		References
		Go to Nemaplex Main Menu		Go to Dictionary of Terminology

Classification:

Chromadorea

  Chromadoria

   Tylenchida
       Tylenchina
        Neotylenchidae

          Deladenus Thorne, 1941

Type species of the genus; Deladenus durus (Cobb, 1922) Thorne, 1941

Synonym

Dotylaphus Andrassy, 1958

Back to Top

Morphology and Anatomy:

• Lip region lw
• Stylet small
• Esophageal-intestinal junction immediately behind the nerve ring
• Median esophageal chamber sometimes present.
• Secretory-excretrory at of slightly behind level of nerve ring
• Long overlap of dorsal esophageal gland over intestine.
• Females without a post-uterine sac.
• Mle with a bursa.
• Two biological forms have been observed in this genus and are considered to constitute a two-part life cycle:
  • a free-living form (mycetophagous stage) observed in all species of the genus
  • an insect-parasitic form (infective stage). The mycetophagous stage has been observed in all the members of the genus.
• Some species are assumed to be non-dimorphic and probably mycetophagus
• The position of the excretory pore relative to the hemizonid is considered an indicator of the life strategies. Excretory poreanterior to the hemizonid in dimorphic species, posetrior to the hemizonid in non-dimorphic species.

Ref: Jalainasab, et al., 2020

Back to Top

Distribution:

Often associated with bark of dead trees.

Back to Top

Feeding:

 Wood (1973) observed Deladenus durus feeding and reproducing on fungi in culture.

Parasites of insects

Some species are considered to have alternative life cycles, one as insect parasitic nematodes and another thought to feed on fungi, algae, or root hairs of higher plants. Examples: Fergusobia, Deladenus (Siddiqi, 2000; Yeates et al., 1993).

Deladenus nitobei is an internal parasite of a wood wasp, Sirex nitobei.. Parasitized wasps are collected as they emerge from dead logs. The parasitism results in a reduction in body size of females (Kanzaki et al., 2018).

Back to Top

Biology and Ecology:

Back to Top

Life Cycle:

Back to Top

Ecosystem Functions and Services:

Back to Top

Management:

Back to Top

References:

Bedding, R. A. and Akhurst, R. J. 1978. Geographical distribution and host preferences of Deladenus species (Nematoda: Neotylenchidae) parasitic in siricid woodwasps and associated hymenopterous parasitoids. Nematologica 24:286-94.

Chitambar, J. J. 1991. On the genus Deladenus Thorne, 1941 (Nemata: Allantonematidae). Review of the mycetophagous stage. Revue de Nematologie 14:427-444

Fenili, R.; Mendes, C. J.; Miquelluti, D. J.; Mariano-da-Silva, S.; Xavier, Y.; Ribas, H. S.; Furlan, G.. 2000. Deladenus siricidicola, Bedding (Neotylenchidae) parasitism evaluation in adult Sirex noctilio, Fabricius, 1793 (Hymenoptera: Siricidae). Revista Brasileira de Biologia  61: 683-687.

Jalainasab, P., Esmaelli, M., Ye, W., Heydari, R. 2020. Description of Deladenus gilanica n. sp. (Hexatylina: Neotylenchidae) isolated from wood of black pine in Northern Iran. J. Nematology 52: | DOI: 10.21307/jofnem-2020-065

Kanzaki, N., S.E. Tanaka, M. Ito, K. Tanaka, B. Slippers and M. Tabata. 2018. Some additional bionomic characters of Deladenus nitobei. Nematology 20:597-599.

Siddiqi, M. R. 2000. Tylenchida: Parasites of plants and insects, 2nd ed. Wallingford: CABI Publishing.

Wood, F.H. 1973. Nematode feeding relationships: Feeding relationships of soil-dwelling nematodes. Soil Riol. Biochem. 5: 593-601.

Yeates, G.W., T. Bongers, R.G.M. de Goede, D.W.Freckman and S.S. Georgieva. 1993. Feeding habits in soil nematode families - an outline for ecologists. Journal of Nematology 25:315-331.

Back to Top

Copyright © 1999 by Howard Ferris.
Revised: February 23, 2024.