Aphelenchoides ritzemabosi
Contents
Rev 10/16/2008
Aphelenchoides ritzemabosi |
Contents |
Rev 10/16/2008 |
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| Chrysanthemum Foliar Nematode |
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Classification |
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Hosts |
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Morphology and Anatomy |
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Life Cycle |
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Economic Importance |
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Damage |
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Distribution |
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Management |
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Feeding |
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References |
Tylenchida
Aphelenchina
Aphelenchoidea
Aphelenchoididae
Aphelenchoidinae
Aphelenchoides ritzemabosi (Schwartz, 1911) Steiner and Buhrer,
1932
Synonyms:
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Aphelenchoides ritzemabosi is 0.77-1.2mm long. Males are common.
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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 |
United States, Europe, Soviet Union, South Africa, New Zealand, and Australia.
Neotype locality is Redwood City, California; original type locality unknown.
C-rated pests in California.
Endoparasite in leaf mesophyll or ectoparasite on buds.
Nematode moves in moisture films and enters stomata.
Chrysanthemum, strawberry.
Similar to A. fragariae.
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.
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.
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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.
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.
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Hot-water Temperatures and Submersion Times for Foliar Nematode in Selected Plants
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a Submerge the pots and plants in the hot water and then into clean, cool water.Date 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.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.