About this Key
This key to aquatic insect orders is written in Lucid3.4, a powerful interactive key application available from the Centre for Biological Information Technology at the University of Queensland, Australia. Lucid3 consists of two separate applications, the Lucid3 Builder and the Lucid3 Player. The Builder is used to create and deploy interactive keys while the Player provides the user interface to access and use the key. The primary components of a Lucid3 key are a list of entities, a list of features and states, a matrix of scored data for the features and entities (not accessible in the Player), and attached media (images, photographs, html files, web pages, etc.) to provide additional information for the user.
The Interactive Key to the Aquatic Insect Orders of North America consists of 3 separate Lucid3 keys, a key to adults, a key to nymphs and larvae, and a key to pupae and nymphs. This structure was adapted from the dichotomous key to orders published in the 3rd edition (1996) of Merritt and Cummins’, An Introduction to the Aquatic Insects of North America and from the key to orders in Usinger (1956), The Aquatic Insects of California. These interactive keys are meant to complement the comprehensive keys to orders, families, and genera found in the new, 4th edition of An Introduction to the Aquatic Insects of North America by Merritt, Cummins, and Berg published by Kendall/Hunt. Vist the Kendall/Hunt website for more information.
When constructing an interactive key to a higher taxon, such as an insect order, the key author has to account not only for the typical members of the order, but also the atypical species that a user might encounter, even if rarely. For example, the matrix needs to be scored for those mayflies without hind wings or the single caddisfly with brachypterous wings. As such, the author needs a broad familiarity with the diversity of morphologies found throughout the different orders, almost at the species level. We have tried our best to accommodate the morphological diversity found in the North American aquatic insect fauna so that most specimens in hand can be identified to order in the key. We have excluded only two taxa from the key, the hydrophilid (Coleoptera) genus Cercyon, which lacks thoracic legs as larvae, and the lepidopteran family Nepticulidae, which lack prolegs and crochets as larvae. We found it difficult to accommodate these taxa in the key and have it work smoothly. If there are additional taxa that do not key out, please let us know so that we may try to accommodate them in future versions of the key.
In each key, each order in the Entities list contains one to several full habitus illustrations and photographs as well as a URL link to that order in the Tree of Life Web Project. This site contains general information about the order as a whole, not just the aquatic representatives, including information about phylogenetic relationships, additional photographs and illustrations, references, and links to other information on the order.