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For Insects, Spiders & Their Kin
For the United States & Canada

affinis complex

Revision of the Nearctic Liodessus affinis (Say 1823) species group (Coleoptera: Dytiscidae, Hydroporinae, Bidessini).
By Miller, K.B. 1998. Entomologica Scandinavica 29(3): 281-314.
Entomologica Scandinavica., 1998
Abstract snippets:

A key is provided for the nine known species of North American Liodessus Guignot. The genus Liodessus is diagnosed, and its taxonomic history and questionable status as a natural group are discussed.

Male genitalia are the only consistently useful structures known for differentiating [the four] species in the L. affinis complex. Females are not distinguishable based on currently known morphological features but may be identified using geographic information. Characters used previously, including coloration, punctation and general shape are too variable within and between species to be useful for species diagnosis or delimitation.

Phylogeny of the Hydroporinae and classification of the genus Peschetius Guignot, 1942 (Coleoptera: Dytiscidae)
By Miller K.B., Wolfe G.W., Biström O.
Insect Syst. Evol. 37: 257-279, 2006

Higher-level phylogeny of diving beetles (Coleoptera: Dytiscidae) based on larval characters
By Michat M.C., Alarie Y., Miller K.B.
Syst. Entomol. 10.1111/syen.12243: 1-34, 2017

Diving beetles of the world: systematics and biology of the Dytiscidae
By Miller K.B., Bergsten J.
JHU Press. 336 pp., 2016

Phylogenetic placement of the Pacific Northwest subterranean endemic diving beetle Stygoporus oregonensis Larson & LaBonte ...
By Kojun Kanda, R. Antonio Gomez, Richard Van Driesche, Kelly B. Miller, David R. Maddison
ZooKeys 632: 75-91, 2016
Full title: Phylogenetic placement of the Pacific Northwest subterranean endemic diving beetle Stygoporus oregonensis Larson & LaBonte (Dytiscidae, Hydroporinae)
Full text (PDF)

Aquatic entomology: The fisherman's and ecologist's illustrated guide to insects and their relatives
By McCafferty, W.P. and Provonsha, A.
Jones and Bartlett Publishers, Inc, 1981
Not intended to be an exhaustive guide to aquatic insects but quite useful as a starter. Still available through Amazon.

Amazon link

World Catalogue of Insects. Vol. 3: Dytiscidae (Coleoptera).
By Nilsson, A.N.
Apollo Books, Stenstrup., 2004
Full PDF

Being a corrected and updated version of the printed catalogue:

Nilsson, A.N. 2001. Dytiscidae (Coleoptera). World Catalogue of Insects. Vol. 3. Apollo Books, Stenstrup. 395 pp.

And including the information given in the following three publications:

Nilsson, A.N. 2003a. World Catalogue of Dytiscidae – corrections and additions, I (Coleoptera: Dytiscidae). Koleopterologische Rundschau 73: 65-74.

Nilsson, A.N. 2004. World Catalogue of Dytiscidae – corrections and additions, 2 (Coleoptera: Dytiscidae). Koleopterologische Rundschau 74: 157-174.

Predaceous Diving Beetles (Coleoptera: Dytiscidae) of the Nearctic Region, with emphasis on the fauna of Canada and Alaska
By D.J. Larson, Y. Alarie, and R.E. Roughley
NRC 43253, 2001
"Dytiscid beetles comprise a large element within the Canadian fauna yet their identification is difficult for the nonspecialist and the distribution and habitats of the species are only sketchily known. The initial and continued aims are to make the predaceous water beetle fauna of Canada accessible to as wide an audience as possible by summarizing available knowledge of the fauna, documenting the species present and their distribution and habitats, providing means for the identification of the taxa, and indicating where knowledge is especially lacking and where interesting and possibly productive research avenues lie. To achieve these aims it has been necessary to revise several genera, review the systematic position of many taxa and to seek out immature stages of various taxa. Much new information, including descriptions of new taxa, is included here. This work will aid and encourage others to look at water beetles with increased interest and appreciation and will stimulate research on these as yet poorly understood insects. The Canadian fauna cannot be understood without reference to the overall Nearctic fauna and therefore the scope gradually enlarged over time to include most of the North American fauna. This work treats all Nearctic genera and most species. Detailed treatment is provided for all species known from Canada. Non-Canadian species are treated as fully in some genera, in others these species are included only in keys. Only within genera where some species are too poorly known to allow their definition, are all species not included. The areas with the most incomplete coverage are both the Gulf States and southwestern United States, namely western Texas to southern California. For the rest of the continent, it is hoped that this work will provide a useful identification guide."