Criconematidae Taylor, 1936
Macroposthoniidae (Skarbilovich, 1959)
Madinematidae (Khan, Chawla & Saha, 1975)
Criconematoidea (Siddiqi, 1980)
Caloosiidae (Siddiqi, 1980)
Hemicycliophoridae (Skarbilovich, 1959)
Per Geraert (2010) the family is separated into five subfamilies which inlcude about 18 genera and around 400 valid species.
|Subfamily Macroposthoniinae||Subfamily Discocriconemellinae|
|Subfamily Blandicephalanematinae||Subfamily Hemicriconemoidinae|
A very large number of species has been described within the family, many of nwhich may be invalid. Geraert (2010) has provided an extremely useful framework for the family, including the partitioning of genera into five subfamilies of genera with similar morphometric and morphological characteristics.
Biology and Ecology:
Nematode species in the Criconematidae feed ectoparasitically on plant roots, some at root tips, others in more mature regions of the root, including areas where the root surface is disrupted by lateral root emergence. Long stylets allow penetration and feeding from cells several layers deep at the root tip or in the root cortex.
Common plant hosts for criconematids are grasses and woody perennials. Population levels may be severely underestimated if extraction techniques are used that rely on nematode movement and activity. Density-flotation extraction techniques are more efficient in recovery of these nematodes (Ferris, et al., 2004; Olson et al., 2017)..
Some criconematids have rather thick bodies and are fairly inactive or move rather sluggishly, others are encumbered by a loose extra cuticle layer which impedes their movement. Their exposure on the root surface, and their relative immobility, must render them accessible to predaceous and parasitic organisms in the rhizosphere. That exposure, however, is offset by the protection provided by the thick cuticle in some genera or the extra cuticular sheath in others. Effects of predation are also offset by the partitioning of assimilated resources into production rather than movement. Some very rapid increases in abundance have been documented for Mesocriconema xenoplax in Prunus sp., for example (Ferris, et al., 2004).
Despite the morphologically-based protective mechanisms, some criconematids are quite susceptible to parasitism by predaceous fungi, for example, Hirsutella rhossiliensis, and to egg mortality through the activity of flourescent pseudomonads (Jaffee et al., 1989; Kleupfel et al., 2002).
Ferris, H., M.V. McKenry, B.A. Jaffee, C.E. Anderson, and A. Juurma. 2004. Population characteristics and dosage trajectory analysis for Mesocriconema xenoplax in California Prunus orchards. Journal of Nematology 36:505-516.
Geraert, E. 2010. The Criconematidae of the World. Identification of the family Criconematidae (Nematoda). Academia Press, 615p.
Jaffee, B. A., J. T. Gaspard and H. Ferris. 1989. Density-dependent parasitism of the soilborne nematode Criconemella xenoplax by the nematophagous fungus Hirsutella rhossiliensis. Microbial Ecology 17:193-200.
Kluepfel, D.A., A.P. Nyczepir, J.E. Lawrence, W. Wechter, and B. Leverentz. 2002. Biological Control of the Phytoparasitic Nematode Mesocriconema xenoplaxon Peach Trees. J. Nematology 34:120-123.
Raski, D.J. and Luc, M. 1987. A reappraisal of Tylenchina (Nemata) 10. The
superfamily Criconemaroidea Taylor, 1936. Rev. Nemarol. 10:409-444.