Tylenchorhynchus annulatus is widely associated in tropical and subtropical regions with rice, sugarcane and grasses. M. M. Joshi & J. P. Hollis have noted that swarming populations in greenhouse pots can cause significant reduction in root and shoot length and weight of rice. However, Hollis & S. Keoboonrueng have reported that extremely high rice yields have also been obtained in the presence of high population of T. annulatus in Lousiana and Texas. Hoplolaimus indicus is a widely distributed species in India. H. oryzae is widely distributed and considered a key pest of rice in far East and tropical countries. On rice, it is usually sympatric with one or more species of Hirshmanniella. The non-host crops namely, blackgram, oats, wheat and greengram may be grown in rotation with rice to bring down the populations of Pratylenchus spp.