Currently viewing the category: "Water Beetles"
What's That Bug? does not endorse extermination

Subject: what is this?
Location: Preston county West virginia
June 30, 2017 5:29 pm
I found this while cleaning my pool. Could you please tell me what it is. The pool was drained to clean leaves at the bottom left from the fall.
Signature: not in my pool

Aquatic Beetle Larva

The best we can do is identify this as the aquatic larva of a Water Beetle.

What's That Bug? does not endorse extermination

Subject: Large Army Green Beetle
Location: Terlingua Ranch, West Texas
May 5, 2017 2:37 pm
We found this guy on top of our water catchment barrel in West Texas, next to Big Bend National Park. He was big enough to fit in a teaspoon, which I used to get him out. He sprang off the spoon with those powerful back legs. He didn’t attempt to fly, but it looks as if it has wings of some sort under that hard exterior. I am certainly curious about this one. We see so many unique insects out there, but this one is a mystery. I love his little eyes….
Yes, I did take this photo and you can use it if you would like.
Thank you for any info you could give.
Signature: Jo

Giant Diving Beetle

Dear Jo,
This is a Predaceous Diving Beetle in the genus Dytiscus, and it is an aquatic species that can also fly from one watery environment to another, so finding it on the water catchment barrel makes perfect sense.  At first we thought it must be the Giant Green Water Beetle,
Dytiscus marginicollis, but that species is only reported from the far west, and according to BugGuide:  “posterior yellow band of pronotum broad especially in the middle” and your individual is lacking that band.  Based on this BugGuide image, we now suspect it might be Dytiscus carolinus, though other images of the species show strong grooves in the elytra.  It is described on BugGuide as being “Abdominal sterna colouration reddish to black and elytra with no yellow subapical transverse fascia.”  But for the coloration, that description does fit.  This FlickR image also resembles your individual.  So though we cannot commit to a species, we are confident that this is a Predaceous Diving Beetle in the genus Dytiscus.  Perhaps mardikavana who frequently writes in with identifications might be able to provide a species identification, however we have a previous comment from mardikavana that states:  “I can’t definitely ID it because when you are dealing with dytiscus sp. you need to see the underside as well. “

Correction:  May 14, 2017
Thanks to a comment from Zach Bruder, we learned this is a Giant Diving Beetle,
Cybister fimbriolatus, and according to BugGuide:  “Similar to Dytiscus, but metatarsal claws different. Elytra and pronotum smooth in male. Dilated male protarsus differs in details from that of Dytiscus. Female Cybister has fine furrows on pronotum.”  Here is a BugGuide image of a greenish individual.

What's That Bug? does not endorse extermination

Subject: big black thing
Location: Belgrade, Serbia
March 22, 2017 7:47 am
This just fell from the sky with a loud thump and doesn’t move. I’m 46 and I’ve never seen one.
Signature: Milan Maksimovic

Predaceous Diving Beetle

Dear Milan,
Though this is an aquatic predator, the Predaceous Diving Beetles in the genus
Dysticus, and we believe your individual is in the genus Dysticus, are capable of flying from pond to pond in the event the original pond begins to evaporate.  Here is a BugGuide image for comparison.

Thanks Daniel!
This was far from any still or flowing water, by at least 3-4 miles. It’s possible that some bird picked it up and dropped it since it fell in a straight line from the sky.
Thanks again.

Yes, that is possible.

What's That Bug? does not endorse extermination

Subject: aquatic nymph as prey?
Location: Alexandria, VA
July 30, 2016 5:18 pm
Hi, I observed and photographed a Green Heron capture what I think might be a dragonfly naiad or some other aquatic nymph today at Huntley Meadows in Alexandria, Virginia. I wouldn’t expect a species ID, but do you think this is even an insect? I can’t think of another possibility…. Thanks!
Signature: Seth

Green Heron Eats Water Tiger

Green Heron Eats Water Tiger

Dear Seth,
What marvelous images you have submitted.  This larva appears to be a Water Tiger, the predatory, aquatic larva of a Predaceous Diving Beetle in the genus
Dytiscus.  This posting is a marvelous addition to our Food Chain tag.

Green Heron Eats Water Tiger

Green Heron Eats Water Tiger

Green Heron Eats Water Tiger

Green Heron Eats Water Tiger

What's That Bug? does not endorse extermination

Subject: WHATS THIS BUG??
Location: Northern wisconsin forest (grass)
July 16, 2016 1:41 pm
Hello bugman, my name is jacob, and i found a bug in northern wisconsin that i cant identify. Date is july 15. Translucent head, six legs, large pincers, and maybe a stinger? Found at 2pm. Thanks
Signature: Jacob

Water Tiger

Water Tiger

Dear Jacob,
This is a Water Tiger, the predatory aquatic larva of a Predaceous Diving Beetle.  Since they are aquatic, we don’t understand why you found it on grass in a forest.  See BugGuide for verification of our ID.

Water Tiger

Water Tiger

What's That Bug? does not endorse extermination

Subject: What’s this bug?
Location: Connecticut
July 12, 2016 7:20 pm
Found crawling in yard in CT today, July 12, 2016. Can you help identify? I’m thinking some kind of beetle.
Signature: Rich P

Diving Beetle

Predaceous Diving Beetle

Dear Rich,
This is a Predaceous Diving Beetle in the genus Dytiscus, possibly Dytiscus harrissii that is pictured on BugGuide.  Its range, according to BugGuide, is “transcontinental in Canada, also in the northeastern US and Alaska; most common in the east (in the Great Lakes region), rare in the west.”  Of the entire genus, as this might be a different species, BugGuide notes the habitat is “permanent or temporary freshwater ponds and pools …, plus streams and rivers; usually found on or among aquatic plants” and “adults fly from March to November (varies by species).”  Though this is an aquatic predator, they are capable of flying from pond to pond.  

What's That Bug? does not endorse extermination