Some Effects of Temperature on the Transmission of Pea Enation Mosaic Virus and on the Biology of the Pea Aphid Vector1

Abstract

The transmission of pea enation mosaic virus to sweet pea, Lathyrus odoratus , by the pea aphid, Acyrthosiphon pisum (Harris), was compared at 10°, 20°, and 30°C. Temperature affected virus acquisition more than it did inoculation. Most of the reduction in virus acquisition occurred at 10°C with acquisition access periods of more than 3 hours. The effect of temperature on inoculation was almost entirely associated with reduced transmission efficiency in inoculation access periods equal to or less than 30 minutes at 10°C. The median latent period decreased from 70 hours at 10°C to 25 and 14 hours at 20° and 30°C, respectively. There was evidence that the efficiency of virus transmission was negatively correlated with the length of the latent period. The probability of transmission, after completion of the latent period, decreased with time in serial-transmission experiments. The weighted mean period of retention of inoculativity varied from 29.5 days at 10°C to 13.7 and 4.3 days at 20° and 30°C, respectively. Infective aphids had net reproductive rates and generation times that were similar to noninfective aphids.