Caenodelphax teapae (fowler) (hemiptera: delphacidae): A new natural vector of the mal de río cuarto virus (MRCV, fijivirus) in Argentina

Abstract

Mal de Río Cuarto virus (MRCV) is the causal agent of Mal de Río Cuarto, one of the major diseases of maize in Argentina. It is spread under natural conditions by Delphacodes kuscheli (Insecta: Hemiptera). The presence of other delphacids in areas affected by the disease suggests that they have a role in its epidemiology. In prospective surveys conducted between 2003 and 2006 in the provinces of Tucumán and Salta (northwestern Argentina), Caenodelphax teapae stood out as one of the most abundant species in wild vegetation. The MRCV was experimentally transmitted to wheat through naturally field-infected specimens from Tucumán. The reaction of the virus in serological tests on insects and infected plants as well as the observed symptoms, together with the presence of aggregates of viral particles in phloem cells, confirmed that C. teapae had the ability to transmit the MRCV to wheat from natural populations captured in the province of Tucumán. Evidence showed for the first time that natural populations of C. teapae carry the MRCV and act as vectors of the virus with important implications for the epidemiology of this disease.