Aphelenchoides fragariae

Taxonomy, Common Name, Disease

Hosts

Wide host range. Over 250 hosts in 47 families, including fern, lily, begonia, African violet, strawberry, and many aquatic plants.

Distribution

Temperate and tropical regions.

Life Cycle

Migratory endoparasite in leaves, but also feeds ectoparasitically on leaf and flower buds in strawberry, for example. Nematode enters leaves through stomata or directly. Sexually reproducing; males required. Life cycle completed in 10-13 days; female produces about 30 eggs. Does best in moist, cool situations.

Symptoms-Pathogenicity

Nematode feeding causes blotches and necrotic lesions between veins on leaves which start as water-soaked spots and then turn brown. In strawberries, nematode causes malformed leaves with crinkled edges.

Management

Roguing plants with symptoms. Hot water treatments. Foliar or soil treatments with systemic chemicals.

Characteristics

Aphelenchoides - Females elongate, slender, usually under 1 mm long; lip region flattened to rounded, slightly offset from body. Head skeleton weak, stylet usually less than 20 um long with only small basal thickenings or knobs. Esophagus with well developed median bulb almost filling body width; esophageal glands in a long lobe overlapping intestine dorsolaterally. Vulva posterior (V = 65-75%) with single anterior gonad and usually a post-vulval sac. Tail conical, often about three to five times the anal body width, sometimes ending in minute terminal spike(s). Male esophageal region similar to female; tail end with paired rose-thorn shaped spicules, no gubernaculum or bursa but with three pairs of subventral papillae. When killed by heat the male tail curls ventrally into a 'walking stick' shape.

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. Siddiqi, M.R. 1975. Aphelenchoides fragariae. C.I.H. Descriptions of Plant-parasitic Nematodes. Set 5, No. 74. Commonwealth Institute of Parasitology. C.A.B. International. 4 pages.
  3. Jenkins, W.R. and D.P. Taylor. 1967. Chapter 16. Foliar or Leaf Nematodes: Aphelenchoides and the Coconut Nematode: Rhadinaphelenchus. in Plant Nematology. Reinhold Publishing Corporation, New York. 270 pages. (page 165).
  4. McKenry, M.V. and P.A. Roberts. 1985. Phytonematology Study Guide. University of California Division of Agriculture and Natural Resources Publication 4045. 56 pages. (page 7).
  5. Agrios, G.N. 1969. Plant Pathology. Academic Press, New York. 629 pages. (page 544).