Anguina agrostis

Anguina agrostis	Contents	Rev 09/27/2008
	Classification	Hosts
	Morphology and Anatomy	Life Cycle
Return to Anguina Menu	Economic Importance	Damage
	Distribution	Management
Return to Anguinidae Menu	Feeding	References
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Classification:

Tylenchida
       Tylenchina
        Tylenchoidea
         Anguinidae

Anguininae
Anguina agrostis

Synonyms:

Morphology and Anatomy:


A,C,D=female; B,E,F,G=male

Distribution:

Europe, Australia, Canada, U.S. (especially Pacific Northwest), New Zealand, and former Soviet Union.

37, 46, and 48% of orchard grass seed samples from the Willamette Valley of Oregon during 1996, 1997, and 2000, respectively, containing Anguina galls. The number of galls ranged from 1-24 per 25 g of grass seed (Alderman et al., 2003).

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Feeding:

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Hosts:

Annual and perennial rye grasses and bent grasses.

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Life Cycle:

Similar to A. tritici, except that second stage hatches from egg.

One generation produced per year. Seed gall ruptures when mucoprotein takes up water and expels nematodes. This corresponds to favorable conditions for germination of host seeds.

Nematodes can remain viable in dry, cigar-shaped galls for up to 10 years.

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Damage:

In Australia, a bacterium formerly considered to be Corynebacterium rathayi attaches to nematode cuticle and is carried into seed gall. Corynebacterium rathayi is now reclassified as Clavibacter rathayi and the ryegrass toxicity organism is considered closely related to but may be a new species of Clavibacter (Riley, 1987).

The bacterium outcompetes the nematode for resources in seed gall, increases, and coats surface which becomes sticky and yellow; produces a neurotoxin that causes convulsion and mortality in grazing animals, i.e., "Staggers." - term used for the effect on sheep[ in Australia. The toxin is produced late in season as the gall matures ( Bird and Stynes, 1977).

Livestock poisoning is occasionally reported in the U.S., otherwise, majority of the damage caused by the nematode results in reduction of seed yield.

The relationship between nematode and bacterium is similar to that between A. tritici and Clavibacter tritici that causes Tundu disease of wheat.

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Management:

Detection:

In grasses, seed galls are difficult to detect as they are covered by lemmas and paleas. A small scarifier can be used to remove lemmas and paleas without damage to seeds or galls. That allows visual identification of galls (Alderman et al., 2003).

Management:

One year rotation removes soil infestation of nematodes.
Mechanical seed cleaning removes most galls, but control is more effective when combined with hot water (52 C for 15 min.).

Ryegrass toxicity:

Use selective herbicide to kill ryegrass in pasture.
Burn field in fall to reduce inoculum in spring.
Check for galls and use herbicides to kill inflorescence.

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References:

Alderman SC, Bilsland DM, Griesbach JA, Milbrath GM, Schaad NW, Postnikova E. 2003. Use of a seed scarifier for detection and enumeration of galls of Anguina and Rathayibacter species in orchard grass seed. Plant Disease 87:320-323.

Bird, A.F., Stynes, B.A. 1977. The morphology of a Corynebacterium sp. parasitic on annual ryegrass Phytopathology 67:828-830.