What's That Bug? does not endorse extermination

Ed. Note:
Choosing the Bug of the Month each month is a unilateral decision we make based on currency and interest.  We are so thrilled with the web dialog that sprang up around this posting of the Florida Deepdigger Scarab Beetles, and since Floridians should be encountering them through January, and since there seems to be a dearth of information about them on the web, the decision this month was quite easy.

Beetle Mound Builders
December 30, 2009
Hi Bugman. I’ve got some kind of beetle building mounds all over the property. They do about 25 mounds a day. They might be dung beetles but I don’t know (I tried to match them up with pics online).
My concern is knowing if they are destructive (besides the annoying mounds). I want to do a large vegie garden and so I’m concerned both about the beetles and about insecticide.
A neighbor (I’m new here) said they live in the ground and only build their mounds during the winter but I don’t know if that is correct. I did first notice the mounds when it turned cold here.
They seem to do most of their work at night though I think they build during the day too.
The beetles are about the size of a quarter, maybe a little bigger. They are shiny black, almost bluish when I shine a light on them at night. They have long back legs.
I’ve enclosed a picture of the beetle, the mound and the series of mounds built in just one day.
Would appreciate identifying the type of beetle, knowing whether or not it is destructive and if so what is the best way to control this little lawn beast.
Thanik you.
bugged
Tampa FL

Florida Deepdigger Scarab Beetle

Florida Deepdigger Scarab Beetle

Dear bugged,
We believe this is a Florida Deepdigger Scarab Beetle, Peltotrupes profundus, a species of Earth Boring Dung Beetle, though we are going to request a second opinion from Eric Eaton.  BugGuide only has two images posted from the genus and indicates they are endemic to Florida.  We are also going to try to locate information on the mounds, and we are not sure if the Florida Deepdigger Scarab Beetle is really the party that is constructing them.

Mound

It is a most interesting question.  Is your soil sandy? because BugGuide indicates they are found in sand scrub.  Is the soil consistent with the coloration of the mounds?  The Soil Science Society of America Journal has an online article entitled Soil Mixing by Scarab Beetles and Pocket Gophers in North-Central Florida, but there are no images.

Mounds

Mounds

Aren’t you guys wonderful! I just happened upon your website while trying to investigate this bug. Your info is very appreciated.
Yes, the soil here is quite sandy. There is a layer of some top soil but then it turns to an orangey/yellowish/reddish sand, the color of the mounds. I believe it gets darker red further down as the previous owner had some pvc pipe set up as ballards so when I removed them I had soil borings to examine.
Also, my neighbor was told, when digging his drainfield, that this type of sand is excellent for drainage. This area of Tampa is actually Temple Terrace, named for the then new hybrid temple oranges grown here. My property sits on an old orange grove, so there might be a bit of manure still in the top soil (just a guess; I don’t know).
What is strange is that these mound builders prefer just a few properties near my house, but a block away I don’t see them at all. There is one empty lot here, about an acre in size, and it looks like a moonscape of mounds.
Interesting the conversation at http://bugguide.net/node/view/39946 as it mentions that December is their active season, just now when I am experiencing the little critters.
Thank you so much for your good information. Please do let me know if you find out otherwise or additional from Mr. Eaton.

Eric Eaton forwards identification request to two experts
Daniel:
Florida + scarab = Eric is clueless.  LOL!  I’m sending a copy of my reply here to two eminent authorities on scarab beetles.  Then I will learn something, too!  Sorry I can’t be of more immediate help.
Eric

Arthur Evans forwards identification request to another expert
Paul,
Would you please take a look at the pushups illustrated in the link below and let us all know what you think it is? Many thanks!
Happy holidays to everyone!
Cheers, ART

Confirmation from Paul E. Skelley
Fellow travelers,
You’ve all had it correct. It is Peltotrupes profudus making the mounds. As a new commer to Florida, I am not surprised by Mr. ‘Bugged’ concerns. We get his exact questions several times every year.
The short answer they are really no problem at all. The mounding is temporary, and actually benefitial to the type of grasses we must grow in Florida. As with many related beetles, Peltotrupes is somewhat colonial. Where you find one, you may find many, and yet, none across the road. Some of this may have to do with their habits of provisioning their burrows with dead plant matter, acorns, etc. In fact, I believe there is a study or two that link these beetles with oaks and deep sand. I have never heard of any case of these beetles actually damaging a lawn or garden plants. Their eye-sore, nuisance mounds are easily knocked over and are washed away with a couple rains. Golf course grounds people will argue about the mounds being a problem, but the beetles pose no other problems that we are aware of.
As for control, I would not waste my time or money. The mound is spoils of a narrow burrow that goes straight down. These burrows are known to be 10 ft. deep and there is no way to put enough pesticide in the soil to kill the larvae in the bottom of the burrows. For a bit of fun, if you can quickly scrape the mound away and find an open burrow, then take a straight grass stalk or other long thin object and stick it down the hole. I occasionaly do this with my kids and have seen 3 ft. grass stalks simply disappear down the hole.
Inspite of them being hard to kill with pesticides, habitat destruction and mis-management are destroying many populations of these beetles. Plus, I have not seen them in heavily managed – irrigated lawns and suspect these yards do not provide the conditions or food needed for the beetles.
This is a non-pestiferous endemic part of native Florida, Mr. Bugged should be proud to have such an interesting insect in his yard. I wish I had them where I lived, but I live in an area with more clay in the soils.
Feel free to drop me additional questions if needed, Happy New Year!
Paul E. Skelley, Collections Manager
Florida State Collection of Arthropods

What a wonderful reply from Paul. Please thank him for me. Now of course I feel terrible (& poorer) for having applied insecticide which I will stop immediately and just hose down the mounds.
Thank you Daniel for your good work in this matter.
[no longer] bugged
ps, Paul is exactly correct where he references the preferred environment as there is deep sand here and I’ve a number of oak trees.
I’m very pleased to have this information and hope I did not damage the colony terribly with the poisoning I did prematurely.

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What's That Bug? does not endorse extermination
Location: Tampa, Florida

14 Responses to Bug of the Month January 2010: Florida Deepdigger Scarab Beetle

  1. pestcemetery.com says:

    Those are dung beetle mounds and we see them all the time. The soil here is very sandy with clay beneath that in a lot of areas. The beetles seem to like thinly grassed areas more so rather than spray try planting grass seed or sod. Even with as many mounds as you have spraying is hardly necessary.

  2. stopbuggingme says:

    Ya, pestcemetery, now that I understand what I’m dealing with I will no longer spray. My original concern and why I started spraying was based upon being misinformed by this property’s previous owner who told me they’ve a problem with mole crickets, which I understand can be quite destructive.

    Then I got confused when exploring the mounds and using soapy water to bring up the bugs, as I wasn’t finding mole crickets but these beetles.

    Then even while realizing I wasn’t dealing with crickets but with beetles, in researching them early on it looked like they eat roots which causes defoliation. But now with Paul’s information, I’m comfortable hosting this colony here.

    And of course I’m very proud to have been selected as whatsthatbug’s first bug of the month for 2010. Finally, my 15 minutes of fame, courtesy of (a) dung (beetle).

  3. lol-
    There are lots of bugs you’ll get to enjoy (and not) in our state. I always come here when I’m stumped and Paul is another gold mine it looks like.

    Welcome to Florida, it’s great to have you as a neighbor!

  4. AmyCGoose says:

    Great posting! As a fellow Floridian, I see these beetles regularly. I have very sandy soils and lots of Oaks as well. Its great to have so much information. Thanks again for an awesome webpage!!!

  5. ratsx3chelsea says:

    i have these mounds near my house in the spring, and yes the soil is sandy, but i live in the middle of new york! i’ve never seen a beetle like that.

  6. Sharon Lis says:

    I yhink this is the scarab type beetle I was looking for. I had one on my drape by the slider and it was black, shiney, and huge. I live in ocala florida and the grass here is sparse and soil is sandy. My question is, how did it get in my house? It’s not like you wouldn’t see this thing, it was about 3 inches around

  7. Pepper Terry says:

    Live in Ocala. Have a huge mound of sand that appeared, literally, OVERNIGHT in our yard. Did not see any “bug” type thing around it. Can you tell me what it might be. Not fireants, I know what they are. I see these sandy, huge mounds along the road in uninhabited areas. Just trying to identify it.

    • Paul Skelley says:

      Late to reply to this, just now scanning various pages. There are many animals that make mounds in any given area. In the Ocala area there are many pocket gophers, Geomys pinetus, a rodent that lives underground that makes large mounds from its burrow digging. It is another interesting native of Florida that is having a difficult time due various factors, and regularly is pushed onto roadsides to survive. While the mounding is unsightly and can cause problems to mowers, and the rodent feed on plant roots and shoots, they are a vital part of a healthy sandhill ecosystem. They recycle leached nutrients up to the plants in their mounds, the mounds are also used by a large variety of other animals and plants as nesting or germination site, and their burrows host an entire fauna of other animals that live no where else. I’m glad you recognized these were not fire ant mounds!

      • bugman says:

        Thanks for providing additional information on beneficial mound builders, even though pocket gophers do not fit our definition of a “bug.”

  8. Darryl hamilton says:

    Thanks for the info. I just noticed a plethora of mounds with small hole in the center. Happened to watching a tv program on Dawson bees whose mounds resembled what I have. But believe I have the scarab instead as I have deep sand, oaks and spare grass under camphor trees. Thanks again

  9. If you look closely you will notice that the mounds of scarab beetles, particularly the deep digger, invariably reveal their access tunnel entrance is at the base of the mounds, not in the center. A wonderful resident beetle to have in your yard!

  10. clint says:

    So the bottom line is there is no way to get rid of these mounds caused by beetles. So tired of comments made by people what wonderful bug you have in your lawn. My lawn looks terrible with these mounds of sand turning up over night. I want these bugs dead. Maybe finding there access hole and pouring 5 gallons of gasoline down the hole will do it. 10 pounds of pesticide have done nothing. If you don’t have a solution to this problem why are you people even posting.

  11. D Hamilton says:

    Just get an armadella, guaranteed it will root out and eat them. But be willing to accept the holes!

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