Population dynamics of aphids and incidence of Ethiopian Pepper Mottle Virus in the Central Rift Valley of Ethiopia

Ethiopian Pepper Mottle Virus (EPMV) is an endemic and important disease of pepper in Ethiopia. Ethiopian Pepper Mottle Virus (EPMV) (genus Potyvirus, family Potiviridae) is transmitted by aphid non-persistently. However, the exact roles of aphid vectors in the field epidemiology of the virus were not known. This study was conducted to investigate the population dynamics of aphids in relation to weather and location and their role in transmitting EPMV in the Central Rift Valley of Ethiopia. Aphids were trapped weekly, at two different locations, from April 2006 to March 2007 by using yellow pan traps. The incidences of EPMV-infected plants were monitored. Data on temperature and rainfall were collected. Correlation was made between seasonal population build up of aphids and weather factors, on one hand, and with the incidence of EPMV on the other. The result revealed location and seasonal differences in population build up of aphids. More aphids were trapped at Ziway than Awassa. It was found that temperature had less influence than rainfall on seasonal flights and population build up of aphids at both locations. The incidences of EPMV were also highly correlated with the population build up aphids.