NOTES ON TAXONOMY AND BIOLOGY: Like other cyst forming nematodes, it has sedentary endoparasitic habits. Cysts are persistent tanned sacs derived by the female body and contain the eggs. Cysts persist in soil for many years. Second-stage juveniles (J2) emerge from the cysts, penetrate host roots and establish a specialized feeding site (syncytium) in the stele. They develop into swollen females, which retain the eggs and produce egg masses. Females rupture root cortex and protrude from root surface. At the end of the reproductive phase females die and become small lemon shaped brown cysts. These cysts are ambifenestrate, lack bullae and are provided by a weak underbridge.
GEOGRAPHIC DISTRIBUTION: Reported from Cyprus, Germany, France, Hungary, India, Ireland, Italy, Poland, Portugal, Russia, Sweden, former Czechoslovakia, The Netherlands, UK In the USA., the nematode is reporteded in eight counties of the state of Michigan (Berney and Bird, 1992).
HOSTS: This nematode has a very narrow host range that includes carrot (Daucus carota and D. pulcherrima). Infection of olive trees by this nematode has been reported, but not confirmed.
CROP LOSSES: Under poor nematode management and in sandy soils, crop losses induced by H. carotae range 20-80% (Greco, 1987).
MEANS OF MOVEMENT AND DISPERSAL: This cyst nematode is dispersed with soil debris, plant material and machinery contaminated by the cysts.
RATING: (M) Taking into consideration the damage caused by this nematode in Europe and the establishment of this pest in Michigan, we urge regulatory agencies in commercial carrot producing states to adopt adequate measures in order to prevent the spread of this pest from infested counties in Michigan to other carrot growing areas in the US. Appropriate actions should be evaluated by APHIS in order to minimize the risks of introduction of this nematodes from other countries.
Berney, M. F., and G. W. Bird. 1992. Distribution of Heterodera carotae and Meloidogyne hapla in Michigan carrot production. Journal of Nematology 24 (4S):776-778.
CAB International. 2001. Heterodera carotae. in Crop protection compendium, global module, 3rd editon. Wallingford, UK: CAB International.
Greco, N. 1986. The carrot cyst nematode. Pp.333-346 in F. Lamberti and C.E. Taylor eds. Cyst nematodes. New York: Plenum Press.
Greco, N.1987. Heterodera carotae: Destructive nematode of carrot. Nematology Circular No. 140, Florida Department of Agriculture and Consumer Services, Division of Plant Industry, Gainesville, FL, USA.
Mathews, H. J. P. 1975. Heterodera carotae. CIH descriptions of plant parasitic nematodes set 5, No. 61. St. Albans, UK: Commonwealth Institute of Helminthology.