An interface to the web service methods provided by the United States Department of Agriculture (USDA). The Agricultural Research Service (ARS) provides a large set of databases. The current version of the package holds interfaces to the Systematic Mycology and Microbiology Laboratory (SMML), which consists of four databases: Fungus-Host Distributions, Specimens, Literature and the Nomenclature database. It provides functions for querying these databases. The main function is associations(), which allows searching for fungus-host combinations.In the following case we want to search for the host of a fungus (Rosellinia ligniaria) and the fungal associations for a give host (Fagus sylvatica). From our expert knowledge we already know that these two species are associated. Let's see if the Fungus-Hosts Distributions database from the USDA confirms this hypothesis. We first specify the input species vectors. In this case they they are only one element long (they are allowed to be longer, too).