Aphids are economically important on agricultural crops for a number of reasons. Aphids are plant feeders and extract plant fluids during their feeding process. Although most plants could probably withstand a small amount of feeding, problems may arise when aphid populations are large and this mechanical damage reduces the vigor of the plant and leaves it susceptible. While the mechanical damage can reduce a plant's vigor, some aphids can also serve as vectors of numerous plant viruses that can damage, stress, or kill a plant. A byproduct of aphid feeding, known as "honeydew," can also be problematic. Honeydew, a sweet, clear liquid, is high in plant sugars. This substance collects on adjacent leaves, and in turn serves as a medium for saprophytic fungi. These fungi grow on the leaf surface and reduce the photosynthetic properties and overall vigor of the plant. If honeydew collects on immature fruit, it may cause fruit splitting as the fruit matures. The resulting damage reduces the fruit's marketability or renders it entirely unmarketable. On plants grown for ornamental purposes, the fungi render the plant aesthetically unmarketable. Production of honeydew by aphids can also cause a condition known as "sticky cotton." The honeydew accumulates on cotton lint, lowers the grade of the cotton, and can cause production problems during fiber processing and yarn manufacturing. The following papers have been published for the purpose identifying aphids of importance or potential importance to various North American agricultural commodities. These papers will be helpful for growers, hobbyists, extension workers, and taxonomists for aphid identification. Click on the highlighted text below to view the Adobe Acrobat PDF files. If you don't have Adobe Acrobat PDF Reader, click on the button below for a free copy.
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A substantial segment of our research concentrates on aphid systematics. Entomological systematics is that field which focuses on the discovery, organization, and interpretation of biological diversity. It is generally recognized to include three main tasks: taxonomy, phylogenetic analysis, and classification. Taxonomy is the science of discovering, describing, and naming species or groups of species. Examination of the evolutionary relationships among groups of species is based on phylogenetic analysis and the subsequent classifications are built on the results of these analyses. The following topics represent a portion of the aphid systematic and taxonomic work currently underway or recently completed in the lab.
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