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Transmission Biology of Maize Bushy Stunt Phytoplasma by the Corn Leafhopper (Homoptera: Cicadellidae)

1998; Oxford University Press; Volume: 91; Issue: 5 Linguagem: Inglês

10.1093/aesa/91.5.668

1938-2901

Gustavo Moya‐Raygoza, L. R. Nault,

Entomopathogenic Microorganisms in Pest Control

Effects of temperature and vector age at the time of acquisition on the transmission of maize bushy stunt phytoplasma by the corn leafhopper, Dalbulus maidis (DeLong & Wolcott), were studied. Mean latent period in the leafhopper and transmission rate of the Tlaltizapan maize bushy stunt phytoplasma isolate had a quadratic relation with temperature. Mean latent period was inversely related to temperature from 15 to 25°C. Transmission rate was highest at 20 and 25°C and lowest at 15 and 30°C. The Tlaltizapan isolate was transmitted better when maize bushy stunt phytoplasma was acquired as nymphs than as adults at 15, 20, and 25°C. The transmission biology of 3 maize bushy stunt phytoplasma isolates by D. maidis was compared when leafhoppers acquired phytoplasma as nymphs and were held at 15 and 25°C. Differences among the 3 isolates were found only at 25°C. At this temperature, the Poza Rica isolate had a longer mean latent period and higher transmission rate than the El Batan and Tlaltizapan isolates. Moreover, the Poza Rica isolate had a longer incubation period in the plant host and produced more basal tillering in infected maize than did the other 2 isolates. Based upon biological findings in this study, as well as molecular studies reported elsewhere, we propose that maize bushy stunt phytoplasma has a polyphyletic origin and evolved from strains of the aster yellows phytoplasma.