NOTES ON TAXONOMY AND BIOLOGY: This cyst forming nematode 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 large egg masses. Females rupture root cortex and protrude from root surface. At the end of the reproductive phase, females die and become rounded dark or black cysts. These cysts are ambifenestrate and are provided of a long vulval slit, small ovoid semifenestra, many bullae and a weak underbridge, which is missed in some specimens. Heterodera oryzycola is morphologically close to H.elachista, H. oryzae and H. sacchari. The separation of these species requires morphological and biochemical techniques (Luc, 1986; Nobbs, et al., 1986).
GEOGRAPHIC DISTRIBUTION: This cyst nematode has been reported only in India (CAB International, 2001).
HOSTS: Rice (Oryza sativa) is the primary host. Other hosts include; plantain (Musa paradisiaca.) and a few grasses including bermudagrass (Cynodon dactylon) and signal grass (Brachiaria decumbens).
CROP LOSSES: The damage induced by this nematode on upland rice ranges 17-42 % (Bridge et al., 1990; Kumari and Kuriyan, 1981). Damage has also been reported on bananas (Charles and Venkitesan, 1994).
MEANS OF MOVEMENT AND DISPERSAL: This cyst nematode is dispersed with soil debris and plant material contaminated by the cysts.
RATING: (L) The low rating is based on the limited host range of this nematode and the low chance of its introduction into the US.
Bridge, J., M. Luc, and R. A. Plowright. 1990. Nematode parasites of rice. Pp. 69-108. in M. Luc, R. A. Sikora, and J. Bridge eds. Plant parasitic nematodes in tropical and subtropical agriculture. Wallingford, UK: CAB International.
CAB International. 2001. Hetrodera oryzicolain Crop protection compendium, global module, 3rd edition. Wallingford, UK: CAB International.
Luc, M. 1986. Cyst nematodes in equatorial and hot tropical regions Pp.355-372. in F. Lamberti and C.E. Taylor eds. Cyst nematodes. New York: Plenum Press.
Charles, J. S. K., and T. S. Venkitesan. 1994. Control of cyst nematode, Heterodera oryzicola in banana cv. Nendran with nematicides. Annals of Plant Protection Science 2:49-51.
Kumari, U., and J. K. Kuriyan. 1981. Cyst nematode, Hetrodera oryzycola in Kerala. I. Estimation of loss in rice due to H. oryzicola infestation, in field conditions. Indian Journal of Nematology 11:106.
Nobbs, J. M., S. K. Ibrahim, and J. Rowe. 1992. A morphological and biochemical comparison of the four cyst nematodes species, Heterodera elachista, H. oryzicola, H. oryzae, and H. sacchari (Nematoda:Heteroderidae) known to attack rice. Fundamental and Applied Nematology 15:551-562.