Thrips are the key arthropod pest of onions in Georgia. Historically, this pest complex has been reported to consist primarily of tobacco thrips, Frankliniella fusca (Hinds), western flower thrips, F. occidentalis (Pergande), and onion thrips, Thrips tabaci Lindeman, with < 1% reported as onion thrips. Onion thrips, however, has become a greater concern in this region because this species is the primary vector of Iris Yellow Spot Virus (IYSV), which was detected in commercial fields in 2003, and both onion thrips and IYSV were detected in culled onions imported from Peru into the Vidalia region in 2003. Surveys were conducted from 2004 through 2010 in commercial onion fields in the 2 primary counties where Vidalia onions are produced to determine whether onion thrips were becoming more prominent within this region. From 2004 through 2006, F. fusca was the predominant pest species collected in this region. Onion thrips were detected and were widely distributed at levels within historical indications. In 2007, onion thrips were detected in commercial fields at levels well above historical levels, representing 49.4% of all pest thrips collected with samples exceeding 90% in some fields. This percentage has steadily declined since 2007, with onion thrips only 1.4% of the total pest thrips collected in 2010 and a maximum of 9.6% in any field. Several factors may have contributed to this shift in species composition including introduction of a more competitive biotype of onion thrips and insecticide resistance within the onion thrips.