Family APHELENCHOIDIDAE

Revised 09/20/23

Classification:

      Chromadorea
     Chromadoria
       Rhabditida
        Tylenchina
         Aphelenchoidea

Aphelenchoididae (Skarbilovich, 1947) Paramonov, 1953

The family Aphelenchoididae includes nematodes with extreley divese feeding habits, including fungal feeders, obligate and facultative plant parasites, predators of nematodes and microinvertebrates, and internal and external insect parasites (Hunt, 1993, 2008; Kanzaki & Giblin-Davis, 2012; Kanzaki, 2014). Many of the taxa have phorewtic relationships with arthropods which facilitates their movenet to new feeding sites.

The family is taxonomically divided into eight subfamilies:

Acugutturinae Hunt, 1980,
Anomyctinae Goodey, 1960,
Aphelenchoidinae Skarbilovich, 1947,
Ektaphelenchinae Paramonov, 1964,
Entaphelenchinae Nickle, 1970,
Parasitaphelenchinae Rï¿½hm, 1956,
Seinurinae Husain & Khan, 1967,
Tylaphelenchinae Kanzaki, Li, Lan & Giblin-Davis, 2014.

Additionally, the family is phylogenetically divided into five clusters:

Clade 1, the basal clade (= Tylaphelenchinae) consists of soil and dead wood-associated fungal feeders,
Clade 2 (= Aphelenchoidinae) is clearly divided into two subclades (2a and 2b) and consists of soil and dead wood-associated fungal feeders and obligate and facultative plant parasites,
Clade 3 (= Acugutturinae, Anomyctinae, Ektaphelenchinae, Entaphelenchinae and Seinurinae) consists of predators, insect and nematode parasites and some fungal feeders,
Clade 4 (= Parasitaphelenchinae) is mostly associated with dead wood, its members feeding on fungi, although a few species parasitise plants and insects. (Kanzaki and Hamaguchi, 2020).

Morphology and Anatomy:

Stylet with knobs ranging from absent, to slightly thickened, to well-developed.
Esophagus with large metacorpus (median bulb), esophageal glands overlapping, usually not enclosed in a bulb.
Spicules characteristically rosethorn-shaped.
Gubernaculum-like structures present or absent.
Males with caudal papillae.
Caudal alae absent or short, terminal.
Phytophagous, mycophagous, predaceous; soil or marine inhabiting, also insect associates.
Often, but not exclusively, associated with ferns, gymnosperms, and monocotyledons. Consequently, Maggenti suggested that the Aphelenchina are an earlier evolutionary group than the Tylenchina.
Type Genus: Aphelenchoides Fischer, 1894.

Ref: Nickle, 1970

Go To Dictionary of Terminology

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

A taxonomic note:

In species descriptions of plant and soil nematodes, it is usual to designate a female nematode as the holotype for the species; Males, if present, are included in the descriptions as paratypes and (quite rarely) one of those may be designated an allotype.

In insect associated nematodes of the Aphelenchoididae and Diplogastridae it has become standard to designate a male as the holotype and list the morphometric charaxcteristics of males before those of females. The reason for using male holotypes is that females of these groups are typically not topologically very informative at the species level. Actually, given the number of cryptic species that are being revealed by use of molecular markers and mating studies, the anatomicakl and morphometric characteristics of males may not be very useful in species designations either (Robin Giblin-Davis, pers. com. November 2018).

Trade dissemination of insect-associated and other nematodes:

Several nematode species, primarily in the Aphelenchoididae and Diplogastridae, have been described from specimens recovered from "packaging wood" at ports of entry into various countries (e.g. Gu et al., 2006; Gu et al. 2013a,b., Wang et al., 2013).

In the United States, All wood packaging material ï¿½ pallets, spools, crates, etc., - coming into the country must pass through USDA APHISï¿½ Border Inspection and Control. Origin countries must comply with specific requirements that include inspection and certification for freedom from pests and organisms in packaging material. All wooden packing material must meet IPPC standards for pest cleanliness. This means that the wood must be heat-treated, fumigated with methyl bromide, and stamped with the IPPC symbol (stamp) ï¿½ with information on the origin, facility where it was processed, and the type of treatment administered. At the port of entry, the receiver is required to declare the shipment and its related documents. If the shipment is not "stamped", it may be sent back to the country of origin.

Inspection of all packing units is not possible and notrequired; Border Control prioritizes shipments containing fleshy botanicals. All fleshy botanicals are considered high risk and are inspected. Any wood units or containers of host materials for fruit flies, or with frass, lesion activity, splitting wood, replacement wood, bark (wooden shipments are to be free of bark). are inspected If organisms are found then they are sent to USDA laboratories for identification (John Chitambar, pers. com., November, 2018)..

References:

Gu, J., Braasch, H., Burgermeister, W., Zhang, J, 2006. Records of Bursaphelenchus spp. intercepted in imported packaging wood at Ningbo, China. Forest Pathology 36:323-333.,

Gu, J., Wang, J., Chen, X., Wang, X. 2013a. Description of Ektaphelenchus ibericussp.n. (Nematoda: Ektaphelenchinae) found in packaging wood from Spain. Nematology 15:871-878.

Gu, J. Wang, J., Chen, X. 2013b. Description of Ektaphelenchus taiwanensis sp.n. (Nematoda: Ektaphelenchinae) found in packaging wood fromTaiwan. Nematology 15:329-338.

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. 2014. Ektaphelenchoides spondylis is a predatory nematode. Nematology 16, 245-247. DOI: 10.1163/ 15685411-00002782

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.

Kanzaki, N., Hamaguchi, K. 2020. Lenisaphelenchus ulomae n. gen., n. sp. (Rhabditida: Aphelenchoididae) isolated from the body cavity of Uloma marseuli Nakane (Coleoptera: Tenebrionidae) from Japan. Nematology 22:961-974

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

Wang, P., Gu, J., Wang, J., Li, H. 2013. Description of Aphelenchoides xui sp.n. (Nematoda: Aphelenchoididae) in packaging wood from South Africa. Nematology 15:279-289.

Return to Aphelenchoididae Menu

Want more information about nematodes? Go to Nemaplex Main Menu.