Gracilacus hamicaudata

Gracilacus hamicaudata	Contents	Rev 02/13/2023
pin nematodes	Classification	Hosts
	Morphology and Anatomy	Life Cycle
Return to Gracilacus Menu	Economic Importance	Damage
	Distribution	Management
Return to Tylenchulidae Menu	Feeding	References
	Go to Nemaplex Main Menu	Go to Dictionary of Terminology

Classification:

Tylenchida
       Tylenchina
        Tyl;enchuloidea
         Tylenchulidae
          Paratylenchinae

Gracilacus hamicaudata Cid & Maggenti, 1988

Synonyms:
Paratylenchus hamicaudatus

Morphology and Anatomy:

Gracilacus hamicaudata: Female body
From Cid del Prado and Maggenti, 1988

Female: Mature females are obese at midbody but posteriorly the body is constricted and hook-shaped with a rounded tail terminus.
Striations of cuticle conspicuous only in anterior and posterior regions.
Cephalic region with four submedian lobes and a circular oral disc.
Vulval-lips protrude and the lateral field is marked with four lines.
Eggs are partially embedded in a gelatinous matrix.

Male: Unknown.

Juvenile: Stylet present, esophagus well developed.

Posterior end of female (SEM). Photograph: I. Cid del Prado

Reported median body size for this species (Length mm; width micrometers; weight micrograms) - Click:

Back to Top

Distribution:

Northern California

Back to Top

Economic Importance:

Back to Top

Feeding:

Feeds in colonies under the root cortex and apparently anchored to enlarged feeding site cells in the phloem parenchyma of secondary roots. The nematode bodies are not exposed to the root surface. Feeding induces cell wall thickening. Giant cell feeding sites are formed in the parenchyma tissue of the vascular cylinder associated with aggregations of nematodes.

At the feeding site, pericycle cells increase in number then collapse and die (Cid del Prado and Maggenti, 1988)

Back to Top

Hosts:

Type host: Redwood: Sequoia sempervirens

For an extensive host range list for this species, click

Back to Top

Life Cycle:

Ecophysiological Parameters:

For Ecophysiological Parameters for this species, click	If species level data are not available, click for genus level parameters

Female attaches to feeding sites in vascular parenchyma by the stylet. Female body swells as gonads mature. Eggs are deposited in a gelatinous matrix which surrounds the female, eggs and and newly hatched J2s under the root cortex (Cid del Prado and Maggenti, 1988).