Ruehmaphelenchus

Ruehmaphelenchus	Contents	Rev 09/20/2023
	Classification	Hosts
	Morphology and Anatomy	Life Cycle
Return to Ruehmaphelenchus Menu	Economic Importance	Damage
	Distribution	Management
Return to Aphelenchoididae Menu	Feeding	References
Go to Nemaplex Main Menu		Go To Dictionary of Terminology

Classification:

       Tylenchida
       Aphelenchina
         Aphelenchoidea
          Aphelenchoididae
           Ektaphelenchinae

Ruehmaphelenchus (Ruehm, 1955), J.B. Goodey, 1963

Type species, Ruehmaphelenchus martinii (Ruehm, 1955) Goodey, 1963

Due to the similarities between Ruehmaphelenchus and Bursaphelenchus, several authors have suggested that Ruehmaphelenchus is a junior synonym ) or a derived clade of Bursaphelenchus. As of 2023, the phylogenetic position of Ruehmaphelenchus in relation to Bursaphelenchus remains unresolved (Gu et al., 2022a; Kanzaki et al., 2013; Kanzaki et al., 2015).

Ruehmaphelenchus was placed in the subfamily Aphelenchoidinae Skarbilovich, 1947 of the family Aphelenchoididae by Hunt, 2008). However, since it has morphological similarities with Parasitaphelenchus Fuchs, 1929 and Bursaphelenchus Fuchs, 1937) it was transferred to Parasitaphelenchinae by Kanzaki & Giblin-Davis (2012).

The genus is differentiated fromParasitaphelenchus6 by its separate, as opposed to fused, spicules and males with a conical tail without a bursal flap (versus males in Parasitaphelenchus and Bursaphelenchus with a bursal flap) (Goodey, 1963; Hunt, 1993; Hunt, 2008; Gu et al., 2022 a,b).

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Morphology and Anatomy:

Body long, slender.
Lip region high, rounded, offset.
Stylet with small basal knobs.

Female:

Monodelphic, prodelphic, long postuterine sac.
Vulval lips protruding.
Female tail short, dome-shaped, with terminal spike.

Male:

Spicules paired, not fused, each with triangular ventral flange.
Male tail with fine terminal spike and 3 pairs of caudal papillae.
Caudal alae and gubernaculum absent.

Ref: Nickle, 1970.

Body size range for the species of this genus in the database - Click:

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Distribution:

Members of the genus Ruehmaphelenchus are primarily insect associates of ambrosia beetles (Scolytinae), especially with Xyleborini and Platypodinae; they are often reported from under the bark of trees. (Kanzaki et al., 2015; Gu et al., 2022b).

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Economic Importance:

The pine wood nematode Bursaphelenchus xylophilus is a serious pest of pines and causes damage in Asia and Europe (Futai, 2013). In China, international shipment of logs and packaging wood materials is considered one of the most important pathways for nematode distribution worldwide, and quarantine inspection is one of the most important measures to stop the spread of pestsInspection of logs and wood packing materials at ports of entry frequently intercepts nematodes of the Aphelenchoididae, including Bursapehelenchus, Ruehmaphelenchus and Parasitaphelenchs. (Gu et al., 2022a,b)

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Feeding:

Probably fungal-feeding. Ruehmaphelenchus hunti, reported from a diseased bulb of Lilium tigrinum intercepted
by Plant Quarantine Inspector N. R. Hunt in a shipment from Japan (Nickle, 1970). Various species have been isolated from dead logs (e.g. Gu et al., 2022).

Of species tested, R. fujianus was successfully cultured on the fungus Botrytis cinerea (Kanzaki, 2021)

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Hosts:

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Life Cycle:

Ecophysiological Parameters:

	Click for genus level parameters

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Damage:

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Management:

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References:

Futai, K. 2013. Pine wood nematode, Bursaphelenchus xylophilus. Annual Review of Phytopathology 51:61-83. DOI: 10. 1146/annurev-phyto-081211-172910

Gu, J., Fang, Y., Ma, X., Lu, X., Chen, X. 2022a. Description of Ruehmaphelenchus taedae n. sp. (Nematoda: Aphelenchoididae) found in Loblolly pine logs from the USA. Nematology 24:149-158.

Gu, J., Fang, Y., Ma, X. 2022b. Description of Ruehmaphelenchus americanum n. sp. (Nematoda: Aphelenchoididae) found in Loblolly pine from the USA. Nematology 24: 777-790.

Hunt, D.J. 1993.. Aphelenchida, Longidoridae and Trichodoridae: their systematics and bionomics. Wallingford, UK, CABI Publishing.

Hunt, D.J. 2008. A checklist of the Aphelenchoidea (Nematoda: Tylenchina). Journal of Nematode Morphology and Systematics 10(2007), 99-135.

Kanzaki, N. 2021. Description of Ruehmaphelenchus fujiensis n. sp. (Tylenchomorpha: Aphelenchoididae) isolated from dead wood of Quercus crispula from Yamanashi, Japan. Nematology 23:725-74.

Kanzaki, N., Giblin-Davis, R.M., Gonzalez, R., Duncan, R. & Carrillo, D. 2015. Description of Ruehmaphelenchus juliae n. sp. (Tylenchina: Aphelenchoididae) isolated from an ambrosia beetle, Xylosandrus crassiusculus (Motschulsky), from South Florida. Nematology 17, 639-653. DOI: 10.1163/ 15685411-00002896

Kanzaki, N., Masuya, H., Taki, H., Okabe, K. & Chen, C.Y. 2013. Description of Ruehmaphelenchus formosanus n. sp. (Tylenchina: Aphelenchoididae) isolated from Euwallacea fornicates from Taiwan. Nematology 15, 895-906. DOI: 10. 1163/15685411-00002728

Kanzaki, N. & Giblin-Davis, R.M. 2012. Aphelenchoidea. In: Manzanilla-Lï¿½pez, R.H. & Marbï¿½n-Mendoza, N. (Eds). Practical plant nematology. Jalisco, Mexico, Colegio de Postgraduados and Mundi-Prensa, Biblioteca Bï¿½sica de Agricultura, pp. 161-208.

Nickle, W.R. 1970. A Taxonomic Review of the Genera of the Aphelenchoidea (Fuchs, 1937) Thorne, 1949 (Nematoda: Tylenchida) . J. Nematology 2:375-392.

Ruehm, W. 1955. Uber einige an holzbrï¿½tende Ipiden gebundene Nematodenarten. Zoologischer Anzeiger 155, 70-83.