Submitted to: Annals of the Entomological Society of America
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: May 20, 2006
Publication Date: November 1, 2006
Citation: Scheffer, S.J., Lewis, M.L. 2006. Mitochondrial phylogeography of the vegetable pest liriomyza trifolii (diptera: agromyzidae): diverged clades and invasive populations. Annuals of the Entomological Society of America. 99:991-998. Interpretive Summary: The American serpentine leafminer is an important pest of many vegetable and flower crops including peas, beans, melons, onions, tomatoes, potatoes, celery, garlic, lettuce, chrysanthemums, and carnations. During outbreaks this insect can cause severe damage to these crops, resulting in substantial economic losses into the millions of dollars. Originally known only from the Americas, this fly has been introduced into many locations around the world. This research investigated the evolutionary relationships of this leafminer species sampled from around the world using DNA sequence data. Results indicate that this species may comprise two or more species. This may explain some of the differences that have been observed in pest status and levels of insecticide resistance between populations from different locations. This research has important implications for quarantine regulations and will be of interest to scientists, pest management specialists, and insect identifiers working with leafminers.
Technical Abstract: The leafmining fly L. trifolii is an important pest of vegetable and cut-flower crops. In recent decades, this species has become invasive, spreading from the Americas to the rest of the world. Despite substantial losses caused by Liriomyza leafminers, the systematics of these flies has remained poorly understood due to their small size and morphological homogeneity. Previous molecular research on other polyphagous Liriomyza pests has suggested that cryptic species may be present. Here we use mitochondrial cytochrome oxidase I sequence variation to investigae phylogeographic structure within L. trifolii. Our results indicate that L. trifolii harbors distinct phylogenetic clades suggestive of the presence of cryptic species. There is also evidence of a recently derived, highly specialized pepper-feeding population within L. trifolii that may represent a host race or even a distinct species. Introduced populations from various locations contained a highly restricted subset of the mitochondrial variation present within L. trifolii, suggesting one or more bottlenecks during colonization.