Monday, May 18, 2020

Episode 525 (5-18-20): Introducing the Water Beetles

Click to listen to episode (4:39)

Sections below are the following:
Transcript of Audio
Audio Notes and Acknowledgments
Extra Information
Related Water Radio Episodes
For Virginia Teachers (Relevant SOLs, etc.)

Unless otherwise noted, all Web addresses mentioned were functional as of 5-15-20.


From the Cumberland Gap to the Atlantic Ocean, this is Virginia Water Radio for the week of May 18, 2020.

MUSIC – ~4 sec – instrumental

This week, we drop in on a musically-enhanced, water-insect competition.  The participants have been challenged to figure out the most species-rich group of insects on the planet, and then come up with the distinguishing words for seven aquatic versions of that group.  Have a listen for about 15 seconds to this entomological exercise, and see if you know the name for that overall group of insects.  And here’s a hint: the name sounds like a revolutionary, four-member rock band.

VOICES and MUSIC - ~15 sec – “Crawling. Long-toed. Predaceous diving. Riffle. Water penny. Water scavenger. Whirligig.”

If you guessed beetles, you’re right!  You heard part of “Beetle Ballet,” by Torrin Hallett, underlying the descriptive names of seven water beetle families.  Scientists categorize beetles into a taxonomic group called an order, and beetles are the most diverse order of animals, with a current estimate of about 390,000 species worldwide.  Perhaps as many as 20,000 of those species are water beetles.  The seven kinds of water beetles you heard, out of about 20 North American families, are among the most commonly found on this continent, with the predaceous diving beetle family and the water scavenger beetle family having the largest number of species.

As a group, water beetles occupy all kinds and sizes of aquatic and semi-aquatic habitats, such as ponds, lakes, and other still waters; streams and rivers; various kinds of wetlands; temporary habitats like puddles; and a variety of moist areas on coastal shorelines.  Beetles that inhabit water typically do so both as adults and in their immature, larval stage; but some, like Water Pennies, are terrestrial as adults, and Long-toed Water Beetles have terrestrial larvae.  All beetle adults have two pairs of wings, with the forewings forming a hardened sheath of the membranous hind wings, and many water beetles are able to hold under those forewings a bubble of air that allows them to breathe while submerged.  Feeding habits among the thousands of water beetle species vary widely, both in what they eat and in how they acquire their food.

Water beetles have many remarkable adaptations and biological variations.  Here’s one example: Whirligig beetles, which can be seen swimming in circles on the surface of ponds, lakes, and still water on stream margins, have eyes divided into an upper and lower half; the upper half can see above the water surface, while the lower half can see below.

Thanks to several Blacksburg, Va., friends for lending their voices to this episode.  Thanks also to Torrin Hallett for composing this week’s music especially for Virginia Water Radio, and we close with the last 20 seconds of “Beetle Ballet.”

MUSIC - ~ 22 sec – instrumental


Virginia Water Radio is produced by the Virginia Water Resources Research Center, part of Virginia Tech’s College of Natural Resources and Environment.   For more Virginia water sounds, music, or information, visit us online at, or call the Water Center at (540) 231-5624.  Thanks to Ben Cosgrove for his version of “Shenandoah” to open and close the show.  In Blacksburg, I’m Alan Raflo, thanking you for listening, and wishing you health, wisdom, and good water.


“Beetle Ballet” is copyright 2020 by Torrin Hallett, used with permission.  Torrin is a 2018 graduate of Oberlin College and Conservatory in Oberlin, Ohio; as of 2020, he is a graduate student in Horn Performance at Manhattan School of Music in New York.  More information about Torrin is available online at  Thanks very much to Torrin for composing the piece especially for Virginia Water Radio. To hear the complete piece (39 seconds), please click here.

The water beetle family names call-outs were recorded by several Blacksburg, Va., residents in May 2020.

Click here if you’d like to hear the full version (2 min./22 sec.) of the “Shenandoah” arrangement/performance by Ben Cosgrove that opens and closes this episode. More information about Mr. Cosgrove is available online at


Whirligig beetles in the New River in Giles County, Va., May 17, 2020.

A species of predaceous diving beetle, Virginia Beach, Va., April 10, 2019.  Photo by Laura Bankey, made available on iNaturalist at (as of 5-18-20) for use under Creative Commons license “Attribtution-NonCommercial 4.0.”  Information about this Creative Commons license is available online at


As noted in the audio, scientists classify beetles scientific classification level called an order.  The scientific names for the beetles order is Coleoptera.  Other orders of familiar insects include Diptera, the order of “true flies”; Hymenoptera, the order of ants, bees, and wasps; and Lepidoptera, the order of butterflies and moths.  (For one list of all insect orders, see Iowa State University’s BugGuide, online at

Families are groups within orders.  Following is some information on the beetles families that include water beetles, that is, beetles that live in or closely associated with aquatic habitats.

J. Reese Voshell, in A Guide to Common Freshwater Invertebrates of North America (McDonald and Woodward, Blacksburg, Va., 2002; (pages 359-368), lists the following seven beetle families as “common in freshwater habitats” in North America.  The families are listed in alphabetical order by common name, with the scientific names for the family in parenthesis.

Crawling Water Beetle (Haplidae)
Long-toed Water Beetles (Dryopidae)
Predaceous Diving Beetles (Dytiscidae)
Riffle Beetles (Elmidae)
Water Pennies (Psephenidae)
Water Scavenger Beetles (Hydrophilidae)
Whirligig Beetles (Gyrinidae)

R. W. Merritt and K. W. Cummins, in An Introduction to the Aquatic Insects of North America, 2nd Edition (Kendall/Hunt, Dubuque, Ia., 1984; (pages 427-437), list the following 21 beetle families as having aquatic or semi-aquatic species in North America (connected either to fresh waters, estuaries, or marine waters).  The families are listed in alphabetical order by scientific name, followed by the family’s common name.

Amphizoidae – Trout-stream Beetles
Carabidae – Predaceous Ground Beetles
Chrysomelidae – Leaf Beetles
Curculionidae – Weevils
Dryopidae – Long-toed Water Beetles
Dytiscidae – Predaceous Diving Beetles
Elmidae – Riffle Beetles
Gyrinidae – Whirligig Beetles
Haliplidae – Crawling Water Beetles
Hydraenidae – Minute Moss beetles
Hydrophilidae – Water Scavenger Beetles
Hydroscaphidae – Skiff Beetles
Limnichidae – Marsh-loving Beetles
Melyridae – Soft-winged Flower Beetles
Noteridae – Burrowing Water Beetles
Psephenidae – Water Pennies
Ptilodactylidae – Toed-winged Beetles
Salpingidae (= Eurystethidae) – Narrow-waisted Bark Beetles
Scirtidae (= Helodidae) – Marsh Beetles
Sphaeriidae – Minute Bog Beetles
Staphylinidae – Rove Beetles


Used for Audio

Iowa State University Department of Entomology, “Bug Guide/Order Coleoptera - Beetles,” online at  This is the source used for the total number of beetle species worldwide.

R. W. Merritt and K. W. Cummins, An Introduction to the Aquatic Insects of North America, Second Edition, Kendall/Hunt, Dubuque, Ia., 1984.

George K. Reid, Pond Life, Golden Press, New York, N.Y., 1967.

Andrew Edward Z. Short, “Systematics of aquatic beetles (Coleoptera): current state and future directions,” Systematic Entomology, Vol. 43/No. 1, January 2018, accessed online at  This is the source used for the total number of water beetle species worldwide.

J. Reese Voshell, A Guide to Common Freshwater Invertebrates of North America, McDonald and Woodward, Blacksburg, Va., 2002.

For More Information about Beetles and Other Insects in Virginia and Elsewhere

University of Michigan Museum of Zoology, “Animal Diversity Web,” online at Beetle species are listed at

Virginia Department of Game and Inland Fisheries, “Fish and Wildlife Information Service,” online at Entries for beetles are available at this link.

Many field guides to insects are available from book stores or other supplies.


All Water Radio episodes are listed by category at the Index link above (  See particularly the “Insects” subject category.

Following are links to other episodes with information related to beetles.

Episode 81, 9-26-11, and Episode 363, 4-10-17 – on stream assessment using aquatic insects and other macroinvertebrates.
Episode P336, 10-3-16 – on streamside insects.

Following are other music pieces composed by Torrin Hallett for Virginia Water Radio, with links to episodes featuring the music.

“Corona Cue” – used in Episode 517, 3-23-20, on the coronavirus pandemic of 2020.
“Geese Piece” – used most recently in Episode 440, 10-1-18, on E-bird.
“Lizard Lied” – used in Episode 514, 3-2-20, on lizards.
“New Year’s Water” – used in Episode 349, 1-2-17, on the New Year.
“Rain Refrain” – used most recently in Episode 455, 1-14-19, on record Virginia precipitation in 2019.
“Spider Strike” – used in Episode 523, 5-4-20, on fishing spiders.
“Tropical Tantrum” – used most recently in Episode 489, 9-9-19, on storm surge.
“Turkey Tune” – used in Episode 343, 11-21-16, on the Wild Turkey.


Following are some Virginia Standards of Learning (SOLs) that may be supported by this episode’s audio/transcript, sources of information, or other materials in the Show Notes.

2013 Music SOLs

SOLs at various grade levels that call for “examining the relationship of music to the other fine arts and other fields of knowledge.”

2010 Science SOLs

Grades K-6 Earth Resources Theme
4.9 – Virginia natural resources, including watersheds, water resources, and organisms.

Grades K-6 Life Processes Theme
1.5 – animals’ basic needs and distinguishing characteristics.
2.4 – life cycles.
3.4 – behavioral and physiological adaptations.

Grades K-6 Living Systems Theme
2.5 – living things as part of a system, including habitats.
3.5 – food webs.
3.6 – ecosystems, communities, populations, shared resources.
5.5 – cell structures and functions, organism classification, and organism traits.

Life Science Course
LS.4 – organisms’ classification based on features.
LS.8 – community and population interactions, including food webs, niches, symbiotic relationships.
LS.9 – adaptations for particular ecosystems’ biotic and abiotic factors, including characteristics of land, marine, and freshwater environments.

Biology Course
BIO.6 – bases for modern classification systems, including structures, biochemistry, and developmental stages.
BIO.8 – dynamic equilibria and interactions within populations, communities, and ecosystems; including nutrient cycling, succession, effects of natural events and human activities, and analysis of the flora, fauna, and microorganisms of Virginia ecosystems.

Virginia’s SOLs are available from the Virginia Department of Education, online at

Following are links to Water Radio episodes (various topics) designed especially for certain K-12 grade levels.

Episode 250, 1-26-15 – on boiling, for kindergarten through 3rd grade.
Episode 255, 3-2-15 – on density, for 5th and 6th grade.
Episode 282, 9-21-15 – on living vs. non-living, for kindergarten.
Episode 309, 3-28-16 – on temperature regulation in animals, for kindergarten through 12th grade.
Episode 333, 9-12-16 – on dissolved gases, especially dissolved oxygen in aquatic habitats, for 5th grade.
Episode 403, 1-15-18 – on freezing and ice, for kindergarten through 3rd grade.
Episode 404, 1-22-18 – on ice on ponds and lakes, for 4th through 8th grade.
Episode 406, 2-5-18 – on ice on rivers, for middle school.
Episode 407, 2-12-18 – on snow chemistry and physics, for high school.
Episode 483, 7-29-19 – on buoyancy and drag, for middle school and high school.
Episode 524, 5-11-20 – on sounds by water-related animals, for elementary school through high school.