Relative growth rates and competitive interactions of Rickettsia infected and uninfected sweetpotato whiteflies (Bemisia tabaci) on cotton

Insect endosymbionts are important drivers of ecological interactions, and may influence an organism’s invasiveness and pest status. A recent study revealed a rapid spread of the endosymbiont Rickettsia among sweetpotato whitefly (Bemisia tabaci, B biotype) populations in the southwestern USA in the early 2000s. While laboratory assays indicated that Rickettsia infection was associated with an increase in whitefly performance, pest managers in the field observed no clear increases in pest characteristics of whiteflies following Rickettsia invasion. To understand whether Rickettsia infection increases growth rates in the field, an experiment was designed to examine population growth and competitive interactions in Rickettsia infected and uninfected whiteflies over a cotton field season. We measured population growth rates and plant growth and nutrition in cages containing either Rickettsia-infected or uninfected whiteflies, as well as changes in Rickettsia infection frequency in population cages initiated with set frequencies of both whitefly types.