Evaluation of local movement of Bemisia tabaci MEAM1 and tomato severe rugose virus transmission to tomato plants using marked and unmarked whiteflies

Abstract

Tomato golden mosaic disease, caused by the tomato severe rugose virus (ToSRV), is one of the most serious tomato diseases. ToSRV is transmitted by the whitefly Bemisia tabaci MEAM1, from a wide range of hosts. Introducing ToSRV in commercial fields probably can occur by transporting the virus from distant locations. However, our hypothesis is that the inoculum causing epidemic development might be related to nearby sources. This study evaluated the short-range flight distance of B. tabaci MEAM1 (marked with detectable proteins and powder dye), through recaptures in yellow sticky traps, and the transmission of ToSRV by viruliferous B. tabaci MEAM1 to tomato plants placed at increasing distances from a release point. Evaluated whiteflies reached a maximum of 30 m from the release point, and no ToSRV-infected tomato plants were detected at greater distances. These findings reinforce the suspicion that the epidemic-supporting source of ToSRV inoculum must be close to commercial cultivation areas. About the efficacy of the type of markers used, of the two protein sources tested (pasteurized chicken egg-white albumin and commercial soy-based extracts as sources of albumin and lecithin, respectively), albumin was considered easier to detect. Marking with these proteins or with two dyes (blue or pink) did not affect B. tabaci MEAM1 mortality, although field tests showed that fewer marked than unmarked insects were recaptured. Dye marking was considered more practical because of the ease of detection. The study validates a new tool to understand the movement of B. tabaci MEAM1, based on different marking methods.