Role of Green Peach Aphid Flights in the Epidemiology of Potato Leaf Roll Disease in the Columbia Basin

Abstract

Three distinct and highly predictable green peach aphid (GPA) (Myzus persicae) flights that occur seasonally in the spring, summer, and fall were detected at a southern, central, and northern location in the Columbia Basin of the Northwestern United States. Intensity and timing of the flights was approximately the same at the three locations. Timing and number of alatae captured in the spring and summer flights was associated with heat unit accumulation. The spring flight, which originates on the overwintering peach tree host, colonized but did not introduce potato leafroll virus (PLRV) into virus-free potato plots. The summer flight, which originates from volunteer potatoes and spring herbs originally colonized by the spring flight, did introduce PLRV into virus-free potatoes. The fall flight was too late to affect potato production. When plots contained a point source of PLRV, the virus spread rapidly in a plant-to-plant mode to all plants in plots after aphids arrived in the spring. Rate of spread from point sources of infection was not affected by timing or intensity of the spring flight, but timing of virus spread in the plots depended on time of arrival of the aphids. Once PLRV was introduced to virus-free plots by the summer flight, virus spread to other plants within the plots. GPA overwintered on peach trees. Although GPA apterae and alatae were present on winter annual weed and crop hosts in the fall, none survived winters on these species. In addition to the GPA, one other vector of PLRV, Macrosiphum euphorbiae, was rarely collected in aphid traps. These results suggest that chemical control of aphids could be delayed until mid-July if PLRV-free potato seed were available.

Phytosanitary status of potato in the Bekaa valley in Lebanon

“…In western Bekaa, PLRV was not present. According to our observations and in line with previous reports, we noticed that early‐season infections reduced yield significantly and much more than late‐season infections (Thomas et al ., 1997). This greatly depends on the use of virus‐free potato seed stocks, which delays the appearance of PLRV in the field and thus reduces the damage it can cause.…”

Innovative Approaches towards Aphid Resistance Prevention in Brassica Crops

“…Such timing gives the greatest benefit in locations where migrant aphids are rarely viruliferous. However, in the Pacific Northwest, PLRV infection rates can approach 100% if M. persicae is not controlled with insecticides [64] . Insecticide resistance often severely limits a grower's choice of aphicides [65] .…”

“…Transgenic lines have been developed that are highly resistant, but not immune, to infection by PLRV, PVY, and PVX [92] . While aphids can still acquire virus from low titre plants, efficiency of transmission is greatly reduced [64] . Transgenic cultivars were released in the USA that expressed the Leptinotarsa decemlineata (Colorado beetle) specific toxin Bacillus thuringiensis var.…”

The effects of monitoring the abundance and species composition of aphids as virus vectors on seed potato production in Serbia

“…They are far more important and damaging as vectors of potato viruses (van Hoof, 1980;Harrington et al, 1986;Piron, 1986;de Bokx, 1987;de Bokx and van der Want, 1987;Weidemann, 1988;Flanders et al 1991;Woodford, 1992;Thomas, 1997;Stevenson, 2001;Sigvald and Hulle, 2004;King et al, 2004;Saucke and Döring, 2004;Milošević et al 2011). Potato viruses are transmitted by winged or wingless forms of both adult aphids and larvae (Robert, 1971, cit.…”