Transmission of Mal de Río Cuarto virus by first and third-instar nymphs of Delphacodes kuscheli

The ability of first and third-instar Delphacodes kuscheli Fennah (Hemiptera: Delphacidae) nymphs to acquire and transmit Mal de Río Cuarto virus (MRCV), under controlled conditions, was investigated. First and third-instar nymphs were allowed acquisition feeding separately on infected wheat plants for 48 hours. The insects were then placed in groups of three for serial transmissions to healthy wheat plants, using inoculation periods of 24 hours. Both instars of D. kuscheli were demonstrated to acquire and subsequently transmit the virus. Nevertheless, transmission trials showed highest transmission efficiency and shortest latent period when MRCV was acquired by first-instar nymphs.Se comparó la capacidad de ninfas de primer y tercer estadío de Delphacodes kuscheli Fennah (Hemiptera: Delphacidae) para adquirir y posteriormente transmitir el Mal de Río Cuarto virus (MRCV), bajo condiciones controladas. Ninfas I y III avirulíferas se alimentaron separadamente de plantas de trigo infectadas durante 48 horas, para luego ser colocadas en subgrupos de tres individuos sobre plantas de trigo sanas. Se realizaron transmisiones seriales utilizando períodos de inoculación de 24 horas. Ambos estadiíos lograron adquirir y transmitir el MRCV, pero se evidenció una mayor cantidad de subgrupos infectivos cuando la adquisición se efectuó como ninfas I, así como una disminución significativa en la duración del período de latencia del virus respecto de los insectos que adquirieron el MRCV durante el tercer estadio ninfalThe ability of first and third-instar Delphacodes kuscheli Fennah (Hemiptera: Delphacidae) nymphsto acquire and transmit Mal de Río Cuarto virus (MRCV), under controlled conditions, was investigated. Firstand third-instar nymphs were allowed acquisition feeding separately on infected wheat plants for 48 hours. Theinsects were then placed in groups of three for serial transmissions to healthy wheat plants, using inoculationperiods of 24 hours. Both instars of D. kuscheli were demonstrated to acquire and subsequently transmit thevirus. Nevertheless, transmission trials showed highest transmission efficiency and shortest latent period whenMRCV was acquired by first-instar nymphs