TRANSMISSION EFFICIENCY OF 3 ISOLATES OF MAIZE STRIPE TENUIVIRUS IN RELATION TO VIRUS TITER IN THE PLANTHOPPER VECTOR

Isolates of maize stripe tenuivirus (MStV) from Florida (US), Costa Ri ca (CR), and Nigeria, Africa (AF), were transmitted to maize plants by the planthopper Peregrinus maidis (from Hawaii) with respective frequ encies of 0, 18, and 60% after a 1-day acquisition access period on di seased plants, and with frequencies of 18, 71 and 93%, respectively, a fter a 7-day access period. These isolates were transmitted transovari ally to progeny planthoppers with respective frequencies of 21, 32, an d 47%. The latent period in the vector, following oral acquisition of MStV, was significantly longer in the US isolate than in the AF- or CR isolates. ELISA tests of MStV-inoculative planthoppers indicated a si gnificantly lower titre of MStV-US compared with MStV-CR or MStV-AF. T hese results suggest that, compared with the US isolate, the AF and CR isolates of MStV multiply faster and reach higher levels in, and are transmitted more efficiently by, P. maidis from Hawaii.