Aphelenchoides ritzemabosi

Aphelenchoides ritzemabosi	Contents	Rev 11/19/2019
Chrysanthemum Foliar Nematode	Classification	Hosts
	Morphology and Anatomy	Life Cycle
Return to Aphelenchoides Menu	Economic Importance	Damage
	Distribution	Management
Return to Aphelenchoididae Menu	Feeding	References
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Classification:

       Tylenchida
       Aphelenchina
         Aphelenchoidea
          Aphelenchoididae
           Aphelenchoidinae
Aphelenchoides ritzemabosi (Schwartz, 1911) Steiner and Buhrer, 1932

Synonyms:

Aphelenchus ritzemabosi Schwartz, 1911
Pathoaphelenchus ritzemabosi (Schwartz, 1911), Steiner, 1932
Aphelenchoides (Chitinoaphelenchus) ritzemabosi (Schwartz, 1911) Fuchs, 1937
Pseudaphelenchoides ritzemabosi (Schwartz, 1911) Drozdovski, 1967
Tylenchus ribes Taylor, 1917
Aphelenchus ribes (Taylor, 1917) Goodey, 1932
Aphelenchoides ribes (Taylor, 1917) Goodey, 1933
Aphelenchus phyllophagus Stewart, 1921

Morphology and Anatomy:

Aphelenchoides ritzemabosi is 0.77-1.2mm long.

Males are common.

Esophageal glands in a long lobe which overlaps the intestine on the dorsal side.
DEGO in large metacorpus.

C,E=female tail with mucro; D,I=male tail with mucro; G,I=male spicules; H=lateral field

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

Distribution:

United States, Europe, Soviet Union, South Africa, New Zealand, and Australia.

Neotype locality is Redwood City, California; original type locality unknown.

Economic Importance:

C-rated pest in California Nematode Pest Rating System.

Feeding:

Endoparasite in leaf mesophyll or ectoparasite on buds.

Nematode moves in moisture films and enters stomata.

Hosts:

Chrysanthemum, strawberry and many others. The following are listed in various literature sources:

Achillea filipendulina Lam.	Fern Leaf Yarrow	Cirsium arvense Scop.	Canada Thistle	Penstemon gentianoides
Aconitum napellus L.	Helmet Flower	Clematis alpina Mill.	Virgin's Bower	Penstemon hirsutus
Adenostyles alpina		Clematis tangutica Korsh.	Virgin's Bower	Penstemon laevigatus
Aegopodium podagraria L.	Goutweed	Clematis vitalba L.	Virgin's Bower	Peperomia caperata	Radiator Plant
Ageratum houstonianum Mill.	Ageratum	Cochlearia officinalis L.	Scurvy Grass	Peperomia glabella	Radiator Plant
Ageratum mexicanum Sims.	Floss Flower	Colchicum sp. L.		Peperomia griseoargentea	Radiator Plant
Allium sativum L.	Garlic	Coleus sp. Lour.	Flame Nettle	Peperomia sp. Ruiz. & Oav.	Radiator Plant
Althyrium sp.		Coleus X hybridus Voss.	Coleus	Peperomia sp. Ruiz. & Oav.	Radiator Plant
Anacyclus pyrethrum		Convolvulus sp. L.	Bindweed	Phaseolus vulgaris L.	Bean
Anemone coronaria L.	Poppy Anemone	Cyclamen persicum Mill.	Florist's Cyclamen	Phlox amoena
Anemone sp. L.	Windflower	Dahlia pinnata Cav.	Dahlia	Phlox douglasii Rose Queen
Anemone sylvestris L.	Windflower	Dahlia sp.		Phlox douglasii May Snow
Anthemis sp. L.	Dog Fennel	Delphinium sp. L.	Larkspur	Phlox douglasii Lilac and Queen
Anthemis tinctoria L.	Golden Marquerite	Diervilla sp. Adans.	Bush-Honeysuckle	Phlox douglasii Boothman's
Anthriscus sylvestris Hoffm.		Doronicum columnae Ten.	Leopard's Bane	Phlox drummondii Hook.	Drummond Phlox
Antirrhinum majus L.	Common Snapdragon	Doronicum cordatum Schultz-Bip.	Leopard's Bane	Phlox paniculata
Apium graveolens Pers. dulce	Celery	Doronicum cordatum ? Schultz-Bip.	Leopard's Bane	Phlox subulata L. Sampson	Ground Pink Phlox
Aquilegia longissima A. Gray	Columbine	Doronicum orientale Hoffm.	Leopard's Bane	Phlox subulata L. Sensation	Ground Pink Phlox
Arabis aubrietioides Boiss.	Rock Cress	Doronicum sp. L.	Leopard's Bane	Phlox subulata L. Lilacina	Ground Pink Phlox
Asplenium nidus L.	Bird's Nest Fern	Doronicum sp. L.	Leopard's Bane	Phlox subulata L. G.F. Wilson	Ground Pink Phlox
Aster alpinus L. altaicus	Michaelmas Daisy	Echinacea purpurea Moench	Purple Cone Flower	Phlox subulata L. Fairy	Ground Pink Phlox
Aster caucasicus Willd.	Michaelmas Daisy	Elsholtzia ciliata Hyl.		Phlox subulata L. Betty	Ground Pink Phlox
Aster dumosus L.	Michaelmas Daisy	Epilobium montanum L.	Fireweed	Phlox subulata L. Atropurpurea	Ground Pink Phlox
Aster novi-belgii L.	Michaelmas Daisy	Epipremnum aureum Bunt.	Pothos	Phlox subulata L. Temiscaming	Ground Pink Phlox
Aster sp. Michaelmas Daisy	Aster	Eremurus stenophyllus O. Fedtsch. bungei		Pilea depressa Blume.
Aster sp. Garnet White	Aster	Erigeron glabellus Nutt.	Fleabane	Plantago major L.	Common Plantain
Aster tradescantii L.	Michaelmas Daisy	Erigeron uniflorus L.		Poa annua L.	Annual Blue Grass
Begonia sp.	Begonia	Erigeron villarsii Bell		Podophyllum peltatum L.	Mayapple
Bellis perennis L.	English Daisy	Forsythia suspensa Vahl	Golden-Bells	Polypodiaceae sp.	Polypody Family
Bellis sp. L.	Daisy	Fragaria chiloensis Duchesne	Strawberry	Prenanthes alba
Blechnum orientale L.		Fragaria chiloensis Duchesne	Strawberry	Primula wanda	Primrose
Brunnera macrophylla I. M. Johnst.	Siberian Bugloss	Fragaria sp. L.	Strawberry	Primula X polyantha Hort.	Polyanthus
Buddleia davidii Franch.	Butterfly Bush	Fragaria vesca L.	Strawberry	Prunus cerasus L.	Sour Cherry
Buddleia davidii Franch.	Butterfly Bush	Fragaria X ananassa	Strawberry	Ranunculus acris L.	Tall Buttercup
Buddleia globosa Hope.	Butterfly Bush	Gaillardia X grandiflora Hort. Wirral Flame	Blanket Flower	Ranunculus auricomus
Bunias orientalis L.	Turkish Rocket	Galium aparine L.		Ranunculus repens
Calceolaria sp. L.	Slipperwort	Goniolimon speciosum Boiss.	Statice Speciosa	Ribes nigrum L.	Black Currant
Calendula officinalis L.	Pot Marigold	Helenium autumnale L.	Sneezeweed	Ribes sanguineum
Callistephus chinensis Nees.	China Aster	Helenium sp. L.	Sneezeweed	Ribes sp. L.	Currant
Callistephus sp. Cass.		Helianthus annuus L.	Sunflower	Ribes uva-crispa	English Gooseberry
Campanula rapunculoides L.	Rover Bellflower	Helianthus decapetalus L.	Thin Leaf Sunflower	Ribes uva-crispa	English Gooseberry
Campanula sp. L.	Bellflower	Helianthus tuberosus L.	Jerusalem artichoke	Rubus idaeus L.	Garden Raspberry
Capsella bursa-pastoris Medic.	Shepherd's Purse	Heliopsis helianthoides Sweet. scabra	Oxeye	Rudbeckia fulgida Perdue speciosa
Centaurea jacea L.	Brown Knapweed	Hepatica americana/nobilis Ker-Gawl./Gars.	Liverleaf	Rudbeckia laciniata L.
Centaurea montana L.	Mountain Bluet	Heuchera sanguinea Engelm	Coralbells	Rudbeckia nitida
Cerastium vulgatum	Mouseear Chickweed	Heuchera sp. L.	Alumroot	Rudbeckia sp. L.	Coneflower
Chamaemelum nobile All.	Chamomile	Impatiens balfourii Hook. f.		Rumex sp. L.	Dock
Chelidonium majus L.	Celandine	Incarvillea delavayi		Saintpaulia ionantha Wendl.	African-Violet
Chenopodium album L.	Lamb's-Quarters	Incarvillea sp.		Saintpaulia sp. H. Wendl.	African Violet
Chrysanthemum balsamita L.	Costmary	Iris sp. L.	Flag	Salix reticulata
Chrysanthemum cinerariifolium Vis.	Pyrethrum	Isatis tinctoria L.		Salvia farinacea
Chrysanthemum coccineum Willd.	Pyrethrum	Knautia arvensis T. Coult.	Blue Buttons	Salvia officinalis L.	Sage
Chrysanthemum indicum L.		Lactuca sativa L.	Lettuce	Salvia pratensis L. Alba	Meadow Clary
Chrysanthemum koreanum Hort.		Lamium album L.	Dead Nettle	Salvia X sylvestris
Chrysanthemum leucanthemum L.	Marguerite	Lamium purpureum	Red Dead-nettle	Sambucus racemosa
Chrysanthemum maximum Ramond.	Max Daisy	Lavandula angustifolia Jord. ex Billot angustifolia	English Lavender	Saxifraga stolonifera Meerb.	Strawberryn Geranium
Chrysanthemum parthenium Bernh.	Feverfew	Lilium henryi Bak.		Scabiosa caucasica Clive Greaves
Chrysanthemum sp. L. Bill Speat	Chrysanthemum	Lilium pumilum Delile	Coral Lily	Scabiosa columbaria
Chrysanthemum sp. L. Pride	Chrysanthemum	Lilium regale E. H. Wils.	Regal Lily	Scabiosa lucida Vill.	Pincushion Flower
Chrysanthemum sp. L. Pennine Snow	Chrysanthemum	Lilium sp. L.	Lily	Sedum maximum
Chrysanthemum sp. L. New Princess	Chrysanthemum	Limonium latifolium O. Kuntze	Sea Lavender	Senecio cruentus
Chrysanthemum sp. L. Lucerne	Chrysanthemum	Limonium vulgare Mill.		Senecio sp.	Cineraria
Chrysanthemum sp. L. Greenwich	Chrysanthemum	Liriope sp.	Lily Turf	Senecio vulgaris	Groundsel
Chrysanthemum sp. L. Evelyn Bush	Chrysanthemum	Lupinus luteus L.	Yellow Lupine	Silene schafta
Chrysanthemum sp. L. Evelyn Bush	Chrysanthemum	Lupinus sp. L.	Lupine	Sinningia sp.
Chrysanthemum sp. L. Covent Garden	Chrysanthemum	Medicago sativa L. Falcon	Alfalfa	Sinningia speciosa Benth. & Hook.	Gloxinia
Chrysanthemum sp. L. Bill Speat	Chrysanthemum	Medicago sativa L. Lahontan	Alfalfa	Solanum lycopersicum L.	Tomato
Chrysanthemum sp. L. Orange Beauty	Chrysanthemum	Medicago sativa L. Ranger	Alfalfa	Solanum nigrum L.	Morelle
Chrysanthemum sp. L. Amy Shoesmith	Chrysanthemum	Medicago sativa L.	Alfalfa	Solidago rupestris
Chrysanthemum sp. L. Orange Peach Blossom	Chrysanthemum	Medicago sativa L. Caliverde 65	Alfalfa	Sonchus arvensis
Chrysanthemum sp. L. Delightful	Chrysanthemum	Medicago sativa L. Cougar	Alfalfa	Sonchus oleraceus L.	Annual Sowthistle
Chrysanthemum sp. L. Orange Peach Blossom	Chrysanthemum	Medicago sativa L. FSRC	Alfalfa	Spilanthes acmella
Chrysanthemum sp. L. Delightful	Chrysanthemum	Medicago sativa L. Moapa 69	Alfalfa	Stachys sylvatica
Chrysanthemum sp. L. Orange Peach Blossom	Chrysanthemum	Medicago sativa L. Vernema	Alfalfa	Stellaria media Cyr.	Chickweed
Chrysanthemum sp. L. Amy Shoesmith	Chrysanthemum	Medicago sativa L. W2S2	Alfalfa	Taraxacum officinale Weber	Dandelion
Chrysanthemum sp. L. Bill Walters	Chrysanthemum	Medicago sativa L.	Alfalfa	Trifolium pratense L.	Red Clover
Chrysanthemum sp. L. Pennine Snow	Chrysanthemum	Mentha X piperita		Urtica dioica L.	Stinging Nettle
Chrysanthemum sp. L. Bill Walters	Chrysanthemum	Mimulus guttatus		Urtica urens	Nettle
Chrysanthemum sp. L.	Chrysanthemum	Mimulus sp. L.	Monkery Flower	Valeriana montana L.	Valerian
Chrysanthemum sp. L.	Chrysanthemum	Morina longifolia Wall.	Whorl-Flower	Verbena rigida K. Spreng	Vervain
Chrysanthemum sp. L.	Chrysanthemum	Nicotiana alata Link & Otto.	Jasmine Tobacco	Veronica agrestis
Chrysanthemum sp. L.	Chrysanthemum	Nicotiana rustica L.	Wild Tobacco	Veronica grandis
Chrysanthemum sp. L.	Chrysanthemum	Nicotiana tabacum L.	Tobacco	Veronica incana
Chrysanthemum sp. L. Pennine Snow	Chrysanthemum	Ocimum sp.		Veronica sp. L.	Speedwell
Chrysanthemum sp. L. Bill Walters	Chrysanthemum	Paeonia sp. L.	Peony	Veronica spicata L.	Speedwell
Chrysanthemum sp. L. Lilac Nymph	Chrysanthemum	Papaver orientale L.	Oriental Poppy	Zinnia elegans Jacq.	Zinnia
Chrysanthemum sp. L. Lilac Nymph	Chrysanthemum	Papaver sp.		Zinnia haageana	Zinnia
Chrysanthemum X morifolium Ramat.	Florist's Mum	Parthenocissus quinquefolia Planch.	Virginia Creeper
Chrysanthemum zawadskii Herbich latilobum	Chrysanthemum	Penstemon barbatus Nutt.	Beard Tongue

For an extensive host range list for this species, click

Males required. After copulation, sperm are stored in the post-uterine sac an move forward into the anterior gonad for fertilization of eggs. One mating provides sufficient sperm to fertilize eggs produced over a period of 6 months (CIH, 1974).

Overwinters in dormant buds and plant material.

Cryptobiotic in dry tissues; viable after 3 years.

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Damage:

Can be a major pest of chrysanthemum. The nematode causes blotches and lesions from endoparasitic feeding in leaves; the lesions are limited by leaf veins resulting in an angular appearance.

Leaf browning is due to oxidation and polymerization of leaf phenols.

Also incites cauliflower disease of strawberry which is an interaction with Rodococcus fascians (formerly Corynebacterium fascians). Cauliflower disease is abnormal and excessive production of axillary buds.

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Management:

1. Roguing and Destruction

Remove and burn infected plants and plant debris.

Fumigate soil or steam in affected areas.

Heat (dry or steam) tools, potting soil and containers at 85C for 30 min.

2. Isolation

Separate suspect from healthy plants until they are confirmed to be noninfected. Remove any tissue suspected of being infected.

3. Propagating Material.

Carefully select nematode-free plants or plant parts for propagation.

Hot water dips are effective for infested propagating stock. Careful temperature control is necessary to kill the nematodes without injuring the plants.

Aphelenchoides ritzemabosi - Chrysanthemum foliar nematode

Hot-water Temperatures and Submersion Times for Foliar Nematode for Selected Plants


Plant	Type/Part	Temp C	Time
African violet	Small potted plants	46.0a	15 min
Anthurium	Bare-root seedlings	46.6	12 min
Begonias	Small potted plants	47.0a	3 min
Chrysanthemum	Dormant stock plants (stools)	46.0	5-15 min
Chrysanthemum	Dormant stock plants (stools)	43.0	20-30 min
Ferns	Small potted plants	43.0a	10-15 min
Lilies	Bulbs	36.0	6 hrs
Lilies	Bulbs	44.0	1 hr
Phlox	Dormant stock plants (stools)	44.0	1 hr
Strawberry	Dormant runner plants	47.0	15 min
Tree peony	Dormant roots	47.0	40 min
Violet	Dormant plants	43.0	30 min

aSubmerge the pots and plants in the hot water and then into clean, cool water.

Data from Edwards, 2000.

4. Avoid Conducive Conditions

Excessive humidity, water on stems and leaves, and contact between plants allow spraad of the nematode among plants. Foliage should only be wet for short intervals. A dry surface mulch on the potting medium or a ring of petroleum jelly around the base of stems will reduce migration of nematodes up plant stems.

5. Alternate Hosts

Maintain outdoor and greenhouse plantings free of weeds. They are potential hosts of foliar nematodes.

6. Fallow

Aphelenchoides ritzemabosi does not survive well in the absence of host plants. Populations may be undetectable after several months in plant-free soil.

7. Host-plant Resistance

Chrysanthemum cultivars 'Amy Shoesmith', 'Delightful', 'Orange Beauty', and 'Orange Peach Blossom' are relatively resistant, but not immune, to A. ritzemabosi. Nematodes invade and feed, but females produce few eggs and resulting juveniles usually fail to mature.

For plants reported to have some level of resistance to this species, click

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References:

CIH Descriptions of Plant-parasitic Nematodes, Set 3, No. 32 (1974)

Edwards, D.I. 2000. Foliar Nematode disease of ornamentals. Univ. Illinois Urbana-Champaign. RPD 1102.

Goodey, J. B., M. T. Franklin, and D. J. Hooper. 1965. T. Goodey's: The Nematode Parasites of Plants Catalogued Under Their Hosts. Commonwealth Agricultural Bureaux, Farnham Royal, Bucks, England. Third Edition

Gray, F. A., J. L. Williams, G. D. Griffin, and T. E. Wilson. 1994. Distribution in the western United States on alfalfa and cultivar reaction to mixed populations of Ditylenchus dipsaci and

Hesling, J. J. and H. R. Wallace. 1960. Susceptibility of varieties of Chrysanthemum to infestation by Aphelenchoides ritzemabosi (Schwartz). Nematologica 5:297-302.

Hesling, J. J., and H. R. Wallace. 1961. Observations on the susceptibility of chrysanthemum varieties infested at two different times with chrysanthemum eelworm, Aphelenchoides

Siddiqui, I. A., S. A. Sher and A. M. French. 1973. Distribution of Plant Parasitic Nematodes in California. State of California Department of Food and Agriculture, Division of Plant Industry. 324p.

Unpublished records of nematodes identified in the quarantine and nursery cerification programs of the Nematology Laboratory, California Department of Food and Agriculture.

Wallace, H. R. 1961. Browning of Chrysanthemum leaves infested with Aphelenchoides ritzemabosi. Nematologica 6:7-16.

Wallace, H. R. 1961. The nature of resistance in Chrysanthemum varieties to Aphelenchoides ritzemabosi. Nematologica 6:49-58.