Paratylenchus hamatus

Taxonomy, Common Name, Disease

1. CLASS: SECERNENTEA
2. SUBCLASS: DIPLOGASTERIA
3. ORDER: TYLENCHIDA
4. SUBORDER: TYLENCHINA
5. SUPERFAMILY: CRICONEMATOIDEA
6. FAMILY: TYLENCHULIDAE
7. SUBFAMILY: PARATYLENCHINAE
   Scientific name - Paratylenchus hamatus
   Common name - pin nematode

   Hosts

   Wide host range. Celery, figs, grapes, and peaches in the San Joaquin Valley.

   Distribution

   Europe and North America. Common in native and cultivated soils.

   Life Cycle

   Migratory ectoparasite. Feeds on mature parts of root on epidermal and outer cortical cells. The fourth stage juvenile shows some resistance to unfavorable environmental conditions.

   Symptoms-Pathogenicity

   Frequently found in very large numbers on woody perennials without causing damage. Associated with crop decline in figs. Causes damage to celery in Northeastern U.S. and the Netherlands; can also deform carrots.

   Importance

   This nematode can occur in very high numbers without apparently causing damage. Don't confuse pin nematode with pinworm.

   Characteristics

   Females small, under 0.5 mm long, often C-shaped when killed by heat. Vulva prominent, posterior, V = 80-90, with single anterior gonad; tail short and conical. Head skeleton weak, stylet small to medium size, 12-40 um long, not flexible. Esophagus criconematid. Males more slender, esophagus degenerate and stylet reduced or absent; spicules narrow, ventrally curved, bursa absent. Juveniles similar to female but fourth stage may have a degenerate esophagus and no stylet.

   References

   1. Evans, K., D.L. Trudgill, and J.M. Webster. 1993. Chapter 1. Extraction, Identification and Control of Plant Parasitic Nematodes. in Plant Parasitic Nematodes in Temperate Agriculture. CAB International, UK. 648 pages.
   2. Jenkins, W.R. and D.P. Taylor. 1967. Chapter 14. Pin Nematodes: Paratylenchus and Sessile Nematodes: Cacopaurus. in Plant Nematology. Reinhold Publishing Corporation, New York. 270 pages. (page 149).