Steneotarsonemus spinki, the panicle rice mite,[1] spinki mite, or rice tarsonemid mite,[2] is a species of mite in the family Tarsonemidae, the white mites. It is a serious pest of rice in tropical Asia, Central America, and the Caribbean.


The panicle rice mite is not visible to the naked eye. A minimum 20× hand lens is required to observe it on the inside of the leaf sheath. The mites are clear to straw-colored and are approximately 250 µm in length. The male has elongated rear legs containing a pair of elongated spines. The legs are carried above the body. Males are highly active and can be seen moving on the surface of the leaf. Females are ovoid-shaped. Larval stages, as well as eggs are about half the size of adults.

Life historyEdit

Parnicle rice mites are parthenogenetic (virgin females can produce male offspring). The female will then mate with the male offspring and produce eggs. A mated female produces an average of 55 eggs in her lifetime. The lifecycle in the laboratory can vary from 3 days at 86 °F to 20 days at 68 °F. If held in the laboratory at 17.6 °F for 72 hours, all parnicle rice mites will die.

High temperatures and low rainfall are ideal for development of large populations of parnicle rice mites in the field. Continuous rice culture and the sharing of equipment between fields is also conducive to building damaging populations of the mites.