Seasonal Abundance of Aphids (Homoptera: Aphididae) in Wheat and Their Role as Barley Yellow Dwarf Virus Vectors in the South Carolina Coastal Plain

Abstract

Aphid (Homoptera: Aphididae) seasonal flight activity and abundance in wheat, Triticum aestivum L., and the significance of aphid species as vectors of barley yellow dwarf virus were studied over a nine-year period in the South Carolina coastal plain. Four aphid species colonized wheat in a consistent seasonal pattern. Greenbug, Schizaphis graminum (Rondani), and rice root aphid, Rhopalosiphum rufiabdominalis (Sasaki), colonized seedlingwheat immediately after crop emergence, with apterous colonies usually peaking in December or January and then declining for the remainder of the season. These two aphid species are unlikely to cause economic loss on wheat in South Carolina, thus crop managers should not have to sample for the subterranean R. rufiabdominalis colonies. Bird cherry-oat aphid, Rhopalosiphum padi (L.), was the second most abundant species and the most economically important. Rhopalosiphum padi colonies usually remained below 10/row-meter until peaking in February or March. Barley yellow dwarf incidence and wheat yield loss were significantly correlated with R. padi peak abundance and aphid-day accumulation on the crop. Based on transmission assays, R. padi was primarily responsible for vectoring the predominant virus serotype (PAV) we found in wheat. Pest management efforts should focus on sampling for and suppressing this aphid species. December planting reduced aphid-day accumulation and barley yellow dwarf incidence, but delayed planting is not a practical management option. English grain aphid, Sitobion avenae (F.), was the last species to colonize wheat each season, and the most abundant. Sitobion avenae was responsible for late-season virus transmission and caused direct yield loss by feeding on heads and flag leaves during an outbreak year.

Antibiosis and antixenosis to Rhopalosiphum padi among triticale accessions

“…Infestations of R. padi cause yield loss to small grains by reducing yield components such as numbers of spikelets and seeds (Kieckhefer & Gellner, 1992;Kieckhefer et al, 1995;Pike & Schaffner, 1985). R. padi vector barley yellow dwarf virus (BYDV), which can cause disease and further yield loss in small grains (Bauske et al, 1997;Chapin et al, 2001;Herbert et al, 1999;McGrath & Bale, 1990;Riedell et al, 1999).…”

Economic Evaluation of the Effects of Planting Date and Application Rate of Imidacloprid for Management of Cereal Aphids and Barley Yellow Dwarf in Winter Wheat

“…In addition, the crop is at greater risk of being infected with the aphidborn BYDV (McGrath and Bale 1990, Hammon et al 1996, Chapin et al 2001, which is associated with fall virus transmission by R. padi (Halbert and Pike 1985, Clement et al 1986, Araya et al 1987. R. padi and S. graminum, although different in their transmission efÞciency, are important vectors of the BYD-PAV strain (Power and Gray 1990).…”

Molecular identification based on coat protein sequences of the Barley yellow dwarf virus from Brazil

“…Usually, the predominance of the BYDV-PAV and the effi cient vector R. padi have been associated with epidemics and yield loss in cereal growing areas (Chapin et al, 2001;Gray et al, 1998). The prevalence of BYDV-PAV in Brazilian growing areas is in line with recent indications of the predominance of the R. padi vector in the fi eld (Silva et al, 2004;Parizoto et al, 2013).…”