Barley yellow dwarf (BYD) is a plant disease caused by the barley yellow dwarf virus (BYDV), and is the most widely distributed viral disease of cereals. It affects the economically important crop species barley, oats, wheat, maize, triticale and rice.
Leafhopper is the common name for any species from the family Cicadellidae. These minute insects, colloquially known as hoppers, are plant feeders that suck plant sap from grass, shrubs, or trees. Their hind legs are modified for jumping, and are covered with hairs that facilitate the spreading of a secretion over their bodies that acts as a water repellent and carrier of pheromones. They undergo a partial metamorphosis, and have various host associations, varying from very generalized to very specific. Some species have a cosmopolitan distribution, or occur throughout the temperate and tropical regions. Some are pests or vectors of plant viruses and phytoplasmas. The family is distributed all over the world, and constitutes the second-largest hemipteran family, with at least 20,000 described species.
The brown planthopper (BPH), Nilaparvata lugens (Stål) is a planthopper species that feeds on rice plants. These insects are among the most important pests of rice, which is the major staple crop for about half the world's population. They damage rice directly through feeding and also by transmitting two viruses, rice ragged stunt virus and rice grassy stunt virus. Up to 60% yield loss is common in susceptible rice cultivars attacked by the insect. The BPH is distributed throughout Australia, Bangladesh, Bhutan, Burma (Myanmar), Cambodia, China, Fiji, India, Indonesia, Japan, North and South Korea, Laos, Malaysia, India, Nepal, Pakistan, Papua New Guinea, Philippines, Sri Lanka, Taiwan, Thailand, and Vietnam. Their alternative host plant other than rice is Leersia hexandra.
Delphacidae is a family of planthoppers containing about 2000 species, distributed worldwide. Delphacids are separated from other "hoppers" by the prominent spur on the tibia of the hindleg.
Rice hoja blanca tenuivirus (RHBV), Spanish for "white leaf rice virus", is a plant virus in the family Phenuiviridae. RHBV causes Hoja blanca disease (HBD), which affects the leaves of the rice plant Oryza sativa, stunting the growth of the plant or killing it altogether. RHBV is carried by an insect vector, Tagosodes orizicolus, a type of planthopper. The virus is found in South America, Mexico, throughout Central America, the Caribbean region, and the southern United States. In South America, the disease is endemic to Colombia, Venezuela, Ecuador, Peru, Suriname, French Guiana and Guyana.
Fijivirus is a genus of double-stranded RNA viruses in the family Reoviridae and subfamily Spinareovirinae. Plants serve as natural hosts. Diseases associated with this genus include: galls (tumours) in infected plants and Fiji disease, with severe stunting, deformation and death. The group name derives from Fiji island the place where the first virus was isolated. There are nine species in this genus.
Maize dwarf mosaic virus (MDMV) is a pathogenic plant virus of the family Potyviridae. Depending on the corn plant’s growth stage, the virus can have severe implications to the corn plant’s development which can also result in economic consequences to the producer of the crop.
Sugarcane mosaic virus (SCMV) is a plant pathogenic virus of the family Potyviridae. The virus was first noticed in Puerto Rico in 1916 and spread rapidly throughout the southern United States in the early 1920s. SCMV is of great concern because of the high economic impact it has on sugarcane and maize.
Rice black-streaked dwarf virus (RBSDV) is a plant pathogenic virus of the family Reoviridae, causing diseases in rice and maize, causing significant crop losses in East Asian countries.
Rice grassy stunt virus (RGSV) is a plant pathogenic virus transmitted by the brown planthopper, Nilaparvata lugens, and two other Nilaparvata species, N. bakeri and N. muiri.
Rice stripe tenuivirus is an RNA plant pathogen of the genus Tenuivirus. It is prevalent in Japan, China, and Korea and can infect plants of the family Poaceae, which include wheat and corn. Damage from this disease causes major reductions in rice crop yield every year.
Peregrinus maidis, commonly known as the corn planthopper, is a species of insect in the order Hemiptera and the family Delphacidae. It is widespread throughout most tropical and subtropical regions on earth, including southern North America, South America, Africa, Australia, Southeast Asia and China. P. maidis are a commercially important pest of maize and its relatives. In addition to physical plant damage, P. maidis is the vector for several species-specific maize viruses, including maize stripe virus, maize mosaic virus and the non-pathogenic Peregrinus maidis reovirus.
Sedoreovirinae was a subfamily of the Reoviridae family of viruses. Viruses in this subfamily are distinguished by the absence of a turreted protein on the inner capsid to produce a smooth surface.
Maize lethal necrosis disease is a viral disease affecting maize (corn) predominantly in East Africa, Southeast Asia and South America, which was recognised in 2010. It is caused by simultaneous infection with two viruses, MCMoV and any of several Potyviridae.
Cytorhabdovirus is a genus of viruses in the family Rhabdoviridae, order Mononegavirales. Plants serve as natural hosts.
Mastrevirus is a genus of ssDNA viruses, in the family Geminiviridae. Mostly monocotyledonous plants serve as natural hosts. They are vectored by planthoppers. There are 45 species in this genus. Diseases associated with this genus include: maize streak virus: maize streak disease (MSD).
Sogatella is a genus of delphacid planthoppers in the family Delphacidae. There are more than 20 described species in Sogatella.
Pepper leaf curl virus(PepLCV) is a DNA virus from the genus Begomovirus and the family Geminiviridae. PepLCV causes severe disease especially in pepper (Capsicum spp.). It can be found in tropical and subtropical regions such as Thailand and India, but has also been detected in countries such as the United States and Nigeria. This virus is transmitted by an insect vector from the family Aleyrodidae and order Hemiptera, the whitefly Bemisia tabaci. The primary host for PepLCV are several Capsicum spp.. PepLCV has been responsible for several epidemics and causes severe economic losses. It is the focus of research trying to understand the genetic basis of resistance. Currently, a source of resistance to the virus has been identified in the Bhut Jolokia pepper.
Sogatella furcifera, also known as the "white-backed planthopper" (WBPH) is a species of planthopper in the family Delphacidae. It is a pest of rice and sorghum in Asia and the Middle East.
Rice polyculture is the cultivation of rice and another crop simultaneously on the same land. The practice exploits the mutual benefit between rice and organisms such as fish and ducks: the rice supports pests which serve as food for the fish and ducks, while the animals' excrement serves as fertilizer for the rice. The result is an additional crop, with reduced need for inputs of fertilizer and pesticides. In addition, the reduction of pests such as mosquito larvae and snails may reduce mosquito-borne diseases such as malaria and dengue fever, and snail-born parasites such as the trematodes which cause schistosomiasis. The reduction in chemical inputs may reduce environmental harms caused by their release into the environment. The increased biodiversity may reduce methane emissions from rice fields.
