Texas Invasive Species InstituteGlobodera rostochiensis
Golden Nematode
Synonym: Heterodera rostochiensis
Class: Secernentea
Order: Tylenchida
Family: Heteroderidae
Photographer: Xiaohong Wang- USDA ARS Image Gallery
Source: http://commons.wikimedia.org/wiki/File:PotatoNematodeCysts.jpg
Description
Since the above ground damage is not visible during the early stages of infestation, the pest can remain undetected for years. The first sign of a golden nematode infestation is poor plant growth in one or more areas of a potato field; and eventually lead to the entire field displaying poor plant growth. Confirmation of the nematode occurs when the plants are uprooted and the parasite’s anatomy is analyzed. Females form the cysts and are very globular with a short neck. New cysts are glossy-brown and have a projecting neck. Females that are newly emerged from the root are yellowish (Figure 1) and distinguishes them from Globodera pallida (another threat to crops) where those females are pure white until they die. Like other nematodes the adults have a thick cuticle, but with a lace-like pattern.
Host Plant: Root crops in the family Solanaceae; primarily potatoes, eggplants and tomatoes
Ecological Threat: The golden nematode is considered to be potentially more dangerous than any other the insects or diseases affecting the potato industry. Since Globodera rostochiensis is able to infect tomatoes, potatoes, eggplants and other crops residing within the family Solanaceae; if this nematode were to expand into other states it would have a devastating impact on the livelihood of Solanaceae farmers and our economy.
Biology: The lifecycle of Globodera rostochiensis has three stages; egg, larva and adult. Altogether it can take 38-48 days to complete. Females break through the root surface (Figure 1), to get fertilized by male nematodes in the soil. The males die right after fertilization and females produce eggs inside and die to become cysts that can be deposited into the soil. The cysts contain about 500 eggs and hatching larvae that can then enter other roots. The eggs remain inactive in the soil until they are stimulated by a chemical released from the roots of the host plant. These nematode cysts can remain dormant for up to 30 years waiting for a host plant to attack. Once the cysts are recognized a host plant, the eggs hatch and the larvae migrate into the roots.
History: This nematode was first discovered in 1941, when it was found to be the cause for serious crop damage in a potato field on Long Island NY. It has spread to about 10 other counties in New York State alone but it has not spread to any other United State, thankfully.
U.S. Habitat: Anywhere that potatoes and tomatoes grow.
Distribution
Native Origin: Andes Mountains of South America
U.S. Present: NY
Management
Globodera rostochiensis is spread by the transport of cysts in soil; which may occur through the movement of soil on farming equipment, seed potatoes, nursery stock, flower bulbs, and potatoes. The main way to control the spread of Globodera rostochiensis is through the systematic planting of nematode resistant potato varieties in rotation with non-host crops. Since the discovery of golden nematode in the United States, more than 40 new nematode-resistant potato varieties have been developed. Nematicides, a chemical product used to control nematodes, may also be used in special situations, as a last resort.
APHIS and the New York State Department of Agriculture and Markets have come up with a few ways to help prevent the spread of the golden nematode:
- Do not use secondhand containers such as burlap bags, crates, and barrels when harvesting potatoes;
- Do not bring used machinery on a farm unless it has been steam-cleaned or fumigated;
- Do not spread soil and debris from potato-grading operations onto farm lands;
- Plant only non-host crops or nematode-resistant potato varieties in rotation with non-host crops on land where golden nematode is known or suspected to occur;
- Plant only certified seed; and
- Rotate crops on potato fields, but do not plant tomatoes or eggplants in the rotation.
Text References
Bélair, G., Simard, L., Laplante, G., & Turcotte, P. 2010. Management of the golden nematode Globodera rostochiensis in Canada. In Proceedings of the 3rd symposium on potato cyst nematodes, Harper Adams University College, UK, 14-15 September 2010. (No. 103, pp. 109-113). Association of Applied Biologists.
Spears, J. F. 1968. The golden nematode handbook. USDA Handbook, 353.
Internet Sources
http://www.aphis.usda.gov/plant_health/plant_pest_info/nematode/index.shtml
http://plpnemweb.ucdavis.edu/Nemaplex/Taxadata/G053s2.htm
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