Behavioral differences in host- finding among two maize disease vectors: Dalbulus maidis (Cicadellidae) and Peregrinus maidis (Delphacidae)

VIRLA EG; COLL MV; JACOBI VG; ZAVALA JA; FERNANDEZ PC

Congreso; 15th International Auchenorrhyncha Congress and 10th International Workshop on Leafhoppers and Planthoppers of Economic Importance; 2017

Among the main maize diseases in Argentina there are those that are caused by maize-stunting pathogens transmitted in a persistent propagative way by the leafhopper Dalbulus maidis and the planthoppers Delphacodes kuscheli and Peregrinus maidis. Dalbulus maidis (DeLong) is considered a serious maize pest throughout most of Latin America, primarily by serving as a vector of Corn Stunt Spiroplasma (CSS), Maize Rayado Fino Virus (MRFV) and Maize Bushy Stunt Micoplasm (MBSM). It is a specialist herbivore feeding only on plants of the genus Zea, maize (Zea mays L.) and its wild relatives, the teosintes (Zea spp.). In Argentina it is present in the NW and NE (Carloni et al. 2013). Although Delphacodes kuscheli is the main vector of Mal de Rio Cuarto Virus (MRCV), the most prejudicial stunting pathogen in Argentina, it has been demonstrated experimentally that Peregrinus maidis (Ashmead), a planthopper present in the center, NE and NW of Argentina, could also transmit MRCV (Virla et al. 2004), besides being a known vector of several other diseases. P. maidis is a more polyphagous insect, although most frequently associated with maize, it has been found on Sorghum spp., Panicum spp., other grasses, and even Citrus (Tesón & Remes Lenicov, 1989).Behavioural differences in host-finding among different maize germplasms have not been studied, and may contribute to the pest status of stunting pathogens vectors. In this study, we compared the preferences of a specialist leafhopper D. maidis (Hemiptera: Cicadellidae) and a more generalist planthopper, P. maidis (Delphacidae) on a suite of three maize cultivars, a temperate and a tropical germoplasm and a landrace. Moreover, we analysed the volatile organic compounds (VOCs) emitted constitutively by the maize plants that could act as non-contact cues determining host-finding.