Peanut ring spot orthotospovirus

Peanut ring spot orthotospovirus (Orthotospovirus arachianuli) is a significant plant pathogen within the Orthotospovirus genus. This virus poses a serious threat to legume crops worldwide, causing systemic infections that can lead to substantial economic losses. Its high level of adaptability and ability to infect various host plants make it a primary concern for agricultural pathology and crop health monitoring programs.

The transmission of this virus is primarily biological, mediated by thrips species such as Thrips palmi. These vectors acquire the virus during their larval stage and retain the ability to transmit it throughout their adult life. The persistent nature of this relationship means that once a population of thrips is infected, they remain an effective source of viral spread until their death, facilitating quick epidemics across fields.

Symptoms of the disease are characterized by chlorotic ringspots, mosaic patterns, and necrotic lesions on the leaves and stems. As the infection progresses, affected plants exhibit stunted growth, leaf distortion, and significant reproductive impairment. Pod development is often restricted, resulting in malformed or discolored seeds that possess low nutritional and commercial value, ultimately impacting the overall yield quality.

Environmental factors, particularly warm and arid conditions, are critical to the development and propagation of this disease. These conditions favor the life cycle of the thrips vectors, increasing their population density and mobility. Furthermore, the presence of alternative weed hosts provides a continuous source of inoculum, allowing the virus to persist in the ecosystem long after the main crop has been harvested or plowed under.

Effective management requires an integrated pest management (IPM) strategy that combines several protective measures. These include:

• Rigorous monitoring of thrips populations using yellow sticky traps.
• Timely application of systemic and contact insecticides to reduce vector pressure.
• Sanitation protocols to eliminate weed hosts around cultivated areas.
• Use of virus-free, certified seeds and resistant crop cultivars where available.
• Strategic crop rotation to break the pest's reproductive cycle and virus transmission chain.