Family HETERODERIDAE

                                   Rev. 06/02/06

Classification:

      Tylenchida
       Tylenchina
        Tylenchoidea 
         Heteroderidae (Filip'ev & Schuurmans Stekhoven, 1941)
    Synonyms:
      Meloidogynidae (Skarbilovich, 1959)
      Meloidoderidae (Golden, 1971)
      Ataloderidae (Wouts, 1973)

Morphology and Anatomy:

Sedentary obligate parasites of roots, forming galls in some cases.
Marked sexual dimorphism, body vermiform and slender in second-stage juveniles, robust in males, and inflated in females. Labial region and cephalic framework well developed, especially in males and juveniles, secondarily reduced in females.
Stylet robust; cone half the length of total stylet.
Dorsal esophageal gland opening close to base of stylet.
Median esophageal bulb usually large, with strong valves.
Esophageal glands overlapping intestine ventrally and also laterally.

Female:

Sedentary in root tissues.
Globose (exception: Verutus with sausage-shaped females).
Vulva generally terminal or subterminal (exception: Verutus and Meloidodera where equatorial). Two genital branches, amphidelphic or prodelphic. Columned uterus with three rows of cells.
Eggs laid in a gelatinous matrix (exception: Verutus) or totally or partially retained within female body of which the cuticle may be transformed (cysts).

Male:

Vermiform. Metamorphosis within juvenile cuticle (exception: Verutus).
No caudal alae (exception: Bursadera).
Tail short or absent.

Second stage juveniles:

Tail conical, with long hyaline posterior part.
Phasmids anterior to half tail length.

Two sub-families:

Characteristic	Heteroderinae	Meloidogyninae
Feeding site	Multinucleate syncytium	Multinucleate giant cell
Host range	Narrow	Wide
Reproductive strategies	Sexual	Mainly parthenogenic
Eggs	Mainly retained in female body	Deposited in egg mass
Female body	Becomes hardened cyst	Does not form cyst
Hatching factors	From host root exudates	Favorable environmental conditions.
Root penetration	Inter- and intracellular migration directly across cortex to zone of cell differentiation.	Longitudinally, mainly intercellularly, toward root tip and then turning into zone of differentiating cells.

References:

Luc, Maggenti & Fortuner, Rev. Nematol. 11:159-176 (1988)

H. Ferris

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