Anita’s Blog – The Clean-Up Crew
- jjvanm
- 6 hours ago
- 5 min read
It was getting deep into November. I still had my moth sheet/black lights going to see if a certain firefly was still in the neighborhood. If it was, it didn’t stop by.
Instead, gazelle scarabs, Digitonthophagus gazella, were nightly visitors, a bit late in the season, I thought.
Another interesting late-night November visitor attracted to the black light was identified as a four-toothed dung beetle, Pseudocanthon perplexus. A dung beetle? That got my attention, as I have not noticed much scat in the yard.
I had not come across a dung beetle – or so I thought – since a long-ago road trip to the Lower Rio Grande Valley National Wildlife Refuge (La Sal del Rey), in Hidalgo County, one scorching July day in 2018.
(Thanks to our Webmaster, Joseph Connors, that road trip account is available: https://legacyblog.stbctmn.org/2018/08/11/anitas-blog-dried-and-salted/)
Going back to my iNaturalist observation of those 2018 dung beetles, I found that they had not been verified.
Early in my iNaturalist.org ventures, I “met” a famous Texas entomologist via comments, questions and responses in some of my uploaded observations. I felt sure he would respond to another question. I edited those earlier fresh-coyote-scat-photos so the dull black beetles were prominent, explained the location, my assumption about the scat, and asked if he could identify the beetles.
Kindly, he quickly wrote back, saying they were “almost surely Canthon imitator.” He included a BugGuide.net reference: https://bugguide.net/node/view/87192
A dung beetle search in my iNaturalist observations brought up species of dung beetles that I had observed in the past but didn’t realize were dung beetles because I had not researched them beyond the identification. Two such October beetle observations were an Ateuchus texanus and a Coprophanaeus pluto.
With so many dung beetles coming to my attention, I thought I’d wrap up the year highlighting this silent but important clean-up crew.
Dung beetles help recycle nutrients and organic matter, aerate the soil and reduce pasture pests and parasites by consuming animal feces/dung/scat/poop. They also bury the dung where female beetles will lay their eggs. Consequently, when larvae hatch, their food supply is already there.
Dung beetles are vital to the health of the ecosystem, be it farmland, forest, rangeland, pasture, prairie, coastal or desert habitats. They keep agricultural and natural ecosystems healthy and productive by breaking down manure piles and getting nutrients back into the soil; the process boosts grass growth, creates more usable forage and increases pasture productivity. By quickly removing manure, pests and parasites are controlled, which saves farmers millions by improving livestock health and pasture quality.
Dung beetles also are an important part of the food web. Birds, opossums, armadillos, ground squirrels, moles, bats, snakes, lizards, frogs, toads, even predatory beetles, like ground beetles and tiger beetles consume dung beetles.
Nearly all dung beetles are members of the Scarab family (Scarabaeidae) of insects. The family includes 35,000 species of beetles worldwide. North America has about seven dozen species, Texas at least 58 species and there are about a dozen species in the Rio Grande Valley.
Dung beetles are the planet’s natural recyclers. They feed on a diverse range of organic matter, some species feed on dung, some on carrion (dead animals) and some on dead and rotting plants.
Dung beetles are stout-bodied, and often clumsy in flight. They have clubbed antennae, the end of which has several plates that can spread out like a fan. The fanning ability helps the beetles locate dung via sensitive chemoreceptors in the antennae which allow them to capture scent particles. The beetles spend most of their time on the ground, but they can fly, sometimes covering several miles to find fresh droppings, often at night.
Interestingly, dung beetles may navigate, orienting themselves by the Milky Way, according a lot of sources; one source is a Guinness World Records link: “The first non-human animal species currently known to navigate and orient itself by using the Milky Way is the nocturnal African dung beetle, Scarabaeus satyrus, native to South Africa, where the study was made.
Earlier this year, while I was observing Rio Grande ground squirrels in our yard, to learn what their diet might include, I saw one eating what looked like a pretty beetle that I’d seen that morning on my moth sheet. The activity was right below the window next to my desk.
After the ground squirrel rapidly finished his snack and scurried away, I went out and collected the bits it left behind, arranged them on white paper and sent a photo of it to my brilliant iNat acquaintance. His return reply said it was possibly a Coprophanaeus pluto.
Coprophanaeus pluto is a good-looking beetle. Its range is southmost Texas, according to BugGuide.net, “in Cameron and Hidalgo counties, plus singleton records from Starr and Willacy counties.” It is a dung beetle, although adults typically feed on carrion instead of dung.
The gazelle scarab, Digitonthophagus gazella, the frequent moth sheet visitor, according to BugGuide.net, it is “of Indoafrican origin, intentionally introduced into Texas for dung control in the 1970s, and it's now, perhaps, the most widespread dung beetle in tropical and subtropical pastures.” Their diet is almost entirely animal feces, particularly cattle dung.
Four-toothed Dung Beetle, Pseudocanthon perplexus. Its range is southern United States to South America. It prefers fresh piles of animal dung and possibly rotten fish. There are only about a dozen observations of this beetle in the Rio Grande Valley and a couple around Austin, on iNaturalist.
Ateuchus texanus. As its scientific species name suggests, texanus, is known for being one of the largest Ateuchus species in North America, nearly one-half inch. It relies on dung from mammals, like white-tailed deer and swamp rabbits.
Canthon imitator, is the dung beetle found during the 2018 La Sal del Rey adventure. These beetles are mainly in Texas, according to observations on iNaturalist. There are a couple observed in Colorado, New Mexico and Oklahoma and a dozen or more in northeast Mexico. They are mostly in regions with open vegetation and sandy soil habitats that are often frequented by coyotes. The beetles also use the droppings of various other carnivores and herbivores.
One more interesting scarab beetle that has been attracted to night lights this year is a hide beetle, Omorgus suberosus. Native to the Americas and introduced globally, their diet includes carrion, dried meat, pet food, feathers and animal hides.
So, the next time you catch yourself wondering what happens to all that crap, now you know.
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In no particular order, following are sources helpful in writing this blog post: National Parks Conservation Association, Missouri, Oklahoma and Texas conservation department fact sheets, NCAT ATTRA Sustainable Agriculture, Science Direct, Texas Insects (TAMU), Wildlife Federation Department and Xerces.org/blog/all-about-dung-beetles-and-why-they-matter by Julia Michaelson