To cite Biotics 5 as a source, follow the citation approach we have established for NatureServe Explorer (see http://www.natureserve.org/explorer/legal.htm#copyright). The sequence is author, year, product, publisher. "NatureServe" is both the "author" and the publisher. Specifically:
NatureServe. 2006. NatureServe Explorer: An online encyclopedia of life [web application]. Version 4.4. NatureServe, Arlington, Virginia. Available at http://www.natureserve.org/explorer. (Accessed: January 16, 2006).
In other words, you cite NatureServe as the "author" or source, followed by the database as the product (analagous to the publication, if it was a book or article). Hence to cite Biotics, use the approach below, changing the dates as appropriate:
NatureServe. 2013. Biotics 5 database. NatureServe, Arlington, Virginia. (Accessed: January 16, 2013).
Of course, if citing data sourced from a network member, reference the member program, as appropriate, rather than NatureServe. The above refers to referencing data from NatureServe Explorer or a multi-jurisdictional data set provided by NatureServe.