Submitted to: Crop Protection
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: June 26, 2009
Publication Date: September 12, 2009
Citation: Simmons, A.M., Ling, K., Harrison Jr, H.F., Jackson, D.M. 2009. Sweet Potato Leaf Curl Virus: Efficiency of Acquisition, Retention and Transmission by Bemisia tabaci (Hemiptera: Aleyrodidae). Crop Protection. 28:1007-1011. Interpretive Summary: The sweetpotato whitefly is an important pest of vegetables and other crops. It feeds on leaves and it can transmit the Sweet Potato Leaf Curl Virus (SPLCV) to sweetpotato and other plants. A study was conducted which helps understand transmission of the SPLCV. The whitefly was found to take a short time to pick up the virus and transmit it to new plants. Once infected, the whitefly remained infected for at least a month, and both male and female whiteflies transmitted the virus. With high numbers of whiteflies, the chance of the virus being transmitted is high. These findings have implications for the management of whitefly-transmitted virus infection in sweetpotato and other crops.
Technical Abstract: The sweetpotato whitefly, Bemisia tabaci (Gennadius), is a global pest which damages plants directly by feeding on leaves. Moreover, the problem is compounded because B. tabaci also vectors numerous plant viruses, including Begomoviruses (Geminiviridae) such as the Sweet Potato Leaf Curl Virus (SPLCV). However, there is little information on the efficiency of SPLCV transmission by B. tabaci. Thus, laboratory experiments were conducted on seedlings of indicator plants, the Brazilian morningglory (Ipomoea setosa Ker Gawl.) and sweetpotato [I. batatas (L.) Lam.], to assess acquisition, retention and transmission of SPLCV by B. tabaci. All evaluations were based on the ability of the adult whitefly to transmit the virus that it had acquired. Two independent techniques, based on the typical expression of symptoms on indicator plants (I. setosa) and the titer of SPLCV DNA as estimated by Real-time quantitative polymerase chain reaction (PCR), were considered to reach the conclusion for a positive SPLCV infection. For virus acquisition, no virus transmission was detected after the insects were exposed to SPLCV-infected plants for <12 h. However, the incidence of transmission increased from exposures of 24 h onward and reached 100% after 84 h. SPLCV was retained and vectored by the whiteflies up to 30 d after the adults were removed from infected plants. It took a minimum of 15 minutes for B. tacaci to vector the virus. Although incidence of transmission increased over time, it only reached about 60% after infected whiteflies were on clean plants for 48 h. Both male and female whiteflies vectored SPLCV. With high numbers of whiteflies, as is common in fields, the chance of them transmitting the virus increases. The findings herein will help to understand the epidemiology of SPLCV in the sweetpotato field. The results will have implications to the numerous viruses that are spread to and among agricultural crops by B. tabaci.