*Author for Correspondence.
S-225 Agricultural Science Center North Lexington, KY 40546 USA.
Tel: (859)-257-5117; Fax: (859)-323-1120.
Email: clbrel2@uky.edu

Abstract.
Wolbachia are a group of obligate intracellular maternally inherited bacteria that have been found in several arthropod groups including spiders, terrestrial crustaceans, and insects, in addition to filarial nematodes. It has been estimated that >65% of insect species harbor Wolbachia, making it one of the most ubiquitous intracellular bacteria discovered to date. In arthropods, Wolbachia behave as a reproductive parasite by manipulating host reproduction to enhance their vertical transmission. One reproductive modification, cytoplasmic incompatibility (CI), has received attention for use in applied strategies targeting economically important insect pests and disease vectors. The two proposed CI-based strategies are: (1) population suppression, analogous to the sterile insect technique (SIT) and (2) population replacement, using Wolbachia as a vehicle to drive desirable phenotypes into natural populations. Strategies are based upon the use of both naturally occurring infections and genetically modified Wolbachia strains. In this review, we summarize recent developments in Wolbachia research, specifically within the context of applied Wolbachia-based strategies used to suppress or modify natural insect populations.