Understanding the breakneck spread of a Rickettsia symbiont in an invasive whitefly: Mechanisms and conditional effects

University Of Arizona, Tucson AZ

Investigators

Abstract

Many insects have bacterial symbionts that live within their cells and are transmitted from mother to offspring in the egg. This project studies the role of such a symbiosis involving a bacterial symbiont, Rickettsia, in adaptation of a host, the invasive sweetpotato whitefly Bemisia tabaci, which is an important agricultural pest. The symbiont has increased dramatically in Arizona, from 1% to 97% of whitefly individuals infected, over just six years. The research team will integrate observational, experimental and molecular approaches to understand why the symbiont spread so effectively. The research will improve understanding of how the spread of the symbiont occurred, of the consequences to the host of having the symbiont, and of how these consequences vary with genetic and environmental characteristics. The interactions of intracellular symbionts and their hosts are potentially important as sources of rapid and long-term adaptation. Acquisition of a symbiont represents a virtually instant adaptation of the host insects. Because the bacteria are inherited, they become a part of the extended genome of their insect hosts, and the insect biology may be permanently altered, for example making a serious agricultural pest like the sweetpotato whitefly more invasive. The knowledge gained by this research may be used to improve pest management or to develop techniques that support beneficial insects. This project also will develop and implement a curriculum supplement on symbiosis and insect biology for middle school classrooms and includes undergraduate research opportunities.