Plant Protection and Quarantine Pest Alert November 2009

Potato Cyst

Features of the cyst . (Photo by Jonathan D. White female on the stolon of a potato. Eisenback, Virginia Polytechnic Institute and State University.) (Photo by Christopher Hogger, Swiss Federal Research Station for Agroecology and Agriculture.)

Background Description PCN spread primarily by the transport of cysts in soil. This Potato cyst nematodes (PCN), PCN are soil-borne organisms may occur with the movement of (pale cyst that do not infest potato tubers. soil on farming, construction, and nematode) and G. rostochiensis The pests infest feeder roots, other equipment; infested soil (golden nematode), have been where the females attach, adhering to seed potatoes and detected in the United States. feed, and become sedentary. other regulated crops; and any G. pallida was found in Idaho Nematodes reproduce sexually. other items or means of transport in 2006, and G. rostochiensis Males are attracted to females (i.e., water) deemed to present a was found in New York in 1941. by a pheromone (sex attractant) hazard for spreading PCN. Although these species are and may mate several times. related, they are very different Females form cysts containing Detection from a regulatory perspective. 200 to 600 eggs, which can stay dormant for up to 30 years while It is essential that public and Among the economically the eggs inside remain viable. private entities work together significant crops, PCN primarily to determine the extent of the affects plants within the potato Large numbers of the nematodes current infestation and prevent family, including potatoes, cause wilting, stunted growth, the further spread of PCN. The tomatoes, , and some poor root development, and early U.S. Department of Agriculture’s weeds. This microscopic worm plant death. If left uncontrolled, (USDA) and Plant Health is a quarantine pest and presents PCN can reduce yields up to 80 Inspection Service (APHIS) is a serious threat to domestic percent in potato fields. Even working cooperatively with the and international commerce in with only minor symptoms States to conduct a national potatoes and nursery stock. showing on the foliage, PCN can survey for PCN every year. significantly reduce tuber size. The purpose is to determine A healthy potato plant (left), compared to one infested with the Female nematodes on potato root. (Photo by Bonsak Hammeraas, potato cyst nematode. (Photo by Christopher Hogger.) Norwegian Institute for Agricultural and Environmental Research.) the distribution and extent of pest’s spread to uninfested USDA is an equal opportunity infestation of this pest in the fields. Each program defines provider and employer. United States. Since the initial separate restrictions for pale finds of pale cyst nematode cyst nematode (G. pallida) Photo credits: All four images in Idaho in 2006 and golden and golden nematode (G. were taken from nematode in New York in 1941, rostochiensis) regarding the www.forestryimages.org APHIS and State officials have movement of plants and soil, and are reproduced by examined hundreds of thousands required sanitation procedures permission. Individual of soil samples from surrounding for equipment, and crop rotation photographers are credited in the production fields, seed potato requirements. Commercial captions. fields, nursery stock, and storage potato, seed potato, and nursery United States and packaging facilities. To stock producers in Idaho and Department of Agriculture date, the nematodes have been New York’s regulated areas who Animal and Plant Health isolated to nine fields within a ship their products intrastate, Inspection Service 1-mile radius in southeastern interstate, or internationally APHIS 81–35–010 Idaho and to nine counties in are subject to these regulatory Revised November 2009 New York. All other soil samples restrictions. collected through the survey have been determined not to For more information contain either species of PCN. To learn more about PCN and Control Measures the regulatory programs currently USDA–APHIS has implemented in place, please visit the APHIS PCN regulatory programs in Web site at www.aphis.usda.gov/ both Idaho and New York that plant_health/plant_pest_info/ are designed to prevent the index.shtml.