24 replies to this topic

[Betta132]

While poking around in the San Gabriel in hopes of finding some water scorpions, I discovered that there are baby toebiters (Lethocerus americanus) hiding under the loose rocks. Hence, I now have two baby toebiters, though I suspect I'll only have one soon- they're different sizes. The larger of the two is about half an inch long, the smaller is maybe a quarter of an inch. They'll be going into a 2.5g, but it needs rearranging/cleaning, so they're just sitting in a cup of river water for now. 

 

My main question is, what water do I put them in? We have a water softener, but our outside water (hoses, sprinklers, etc) isn't hooked up to it. I could also use grocery store RO water or spring water, but hose water (after the hose runs long enough so that the water isn't the stuff that's been sitting in the hose all day) would be easiest. I clearly need an answer for this one first. If I don't get an answer within today, I'm gonna use the spring water I have on hand, plus maybe some dechlorinator just in case. 

 

Second question, what would be the best thing to feed them? I have frozen mysis, frozen bloodworms, frozen krilll, and some slightly freezerburned silversides. I plan to stick the food on a toothpick or hold it in tweezers and just wiggle it in their faces until they chomp it- works for dragonfly larvae and carnivorous beetle grubs. And how big should the food be? A bit smaller than the bug? 

 

Third, what's a good temperature? My room gets pretty cold (I have a window unit and keep it cranked up), and I do have a little heater that keeps the tank at about 76F, which feels about the same as the river. Is that a decent temp for them in the summer?

 

Fourth, about how long will they take to grow to about full size, and how long will they live? Can't seem to find a consistent answer online.

 

Also, apparently if you ask "Anyone wanna see a cool bug?" in the vicinity of a biker gang, the answer will be a resounding yes. Have just shown two baby toebiters to about 10 bikers. Turns out bikers like cool bugs. 

[9darlingcalvi]

I would say live small minnows

[Betta132]

I would really rather not feed them live vertebrates. I have absolutely no desire to watch a fish be injected with acid. Yes, I know they do that in the wild, and they have every right to hunt for food, but I don't want to watch a minnow die slowly. Especially not in the grasp of something that's said to have the most painful bite of any waterbug. I'm not going to starve them, but if they won't eat frozen food, they're going back into the wild. 

 

Turns out I have distilled water on hand. Will that work for the biters?

[9darlingcalvi]

Yes

[Betta132]

I know distilled water is bad long-term because it lacks needed minerals. How could I go about adding said minerals in? Maybe keep a shed exoskeleton from something in there? 

I'll set them up with distilled for now, get them into a gallon or so of nice clean water. They're pretty cool already, puttering around the cup. 

For now, I'm going to put them in the tank with just a few sticks and a thin layer of black sand. Aside from access to air, is there anything I need to be certain I provide? 

[smilingfrog]

I'd just use your home tap water.  Since they breathe air you probably don't even need to de-chlorinate it, though it won't hurt to do so.  For feeding, I would give them something a little smaller than they are.  I don't know how much they eat but would offer them something every few days, and if they always take the food and eat it, I would try increasing the feeding rate or size of food offering.  If they occasionally ignore the food or grab it but then don't eat it, try decreasing the rate of feeding or size of offering.

[swampfish]

It is true that these bugs breathe atmospheric air, but they still need decent water. I have never found giant water bugs in water that fish couldn't live in. I suggest avoiding the salt in the softened water and the chlorine in the tap water. The unsoftened tap water should be dechlorinated first. It should be better than distilled water as it contains minerals the bugs may need.

 

I've kept giant water bugs, water scorpions, water scavenger beetles, and predaceous diving beetles that adapted to eating pelleted fish food. The giant water bugs and water scorpions grabbed the fish food in the water and sucked on it. They lived for a couple of years on it. Any of the frozen foods should be fine. You may need to dangle the food in front of them until they learn what it is. After that, they will go after the food wherever it is. They will grab the food and bring it back near the surface where they can feed at their leisure and still breathe.

 

The size of the food doesn't matter as they don't chew, they suck. For instance, mosquitoes have no trouble sucking blood out of comparatively huge prey, such as humans. The only situation where size becomes a problem is when the prey is alive and large enough to maim or kill the predator.

 

I don't know how long it takes for a Lethoceras to grow up, but I suspect one to two years, depending on water temperature and food quality. My guess is that the adults will live two to three years. Once they become adults, keep the tank covered as they will fly to lights. As long as they are well-fed, they are unlikely to eat each other. The best temperature to keep them would be normal room temperature. Most insect colonies of various species are kept in the mid-70's, so heated to 76 degrees F is probably about right.

 

Phil Nixon

Extension Entomologist

University of Illinois

[Betta132]

Great info, thanks!

I assume they'll be fine in the 2.5g even when they get to full size? These don't seem like active bugs. 

Is there anything I can keep them with? I know where to get those water scorpions that look like underwater walking sticks, and I'm pretty sure I can get some of the little black diving beetles. Is it safe to assume that anything heavily armored and too small to threaten the biters would be good? 

Will definitely keep tank very well closed. I do NOT want toebiters loose in my bedroom. How strong are the adults? The tank's lid is just a pane of glass with a little handle, could they theoretically push it up far enough to wiggle out?  

 

The tank is now set up. They have a thin layer of sand, a few leaves to hide under, a sprig of java fern, and a stick to perch on. They also have indirect light from the light over a nearby betta tank. I'm hoping that they'll get used to the light and stop caring, but if not, I can move the light a bit. Are these reasonably confident insects once they settle in? I'd imagine a hefty bug armed with acid is likely to be fairly bold.

The larger of the two is missing one of its hind legs. It can swim fairly well, it just kinda goes in circles. I can also see its air tank, which is cool. 

[Betta132]

Didn't find any water scorpions in the neighbor's pool/pond. Three kinds of tadpoles, though, and I got some backswimmers. Will the backswimmers attack my biters if I drop 'em in the tank, or vice versa? 

[Betta132]

Biters are hiding behind heater and haven't been noticed by backswimmers. We'll see if that changes.

Backswimmers are, apparently, not compatible with each other. Cannibals.

[swampfish]

Predatory insects are like predatory fish, big and aggressive ones eat little ones. They are opportunists. Realize as I mentioned earlier that sucking insects such as giant water bugs, water scorpions, and backswimmers will eat larger prey as long as they do not risk injury from the prey. Once a true bug bites its prey, it injects a toxin that immobilizes it unless it has a large body mass. I have never heard about true bugs injecting acid, but since human saliva and that of most other animals are acidic, I guess one can jump to that conclusion.

 

Giant water bugs are active and aggressive enough to probably eliminate all other insects, tadpoles, and fish in an aquarium except large fish and beetles. The beetles have thick enough exoskeletons to thwart the giant water bugs, thought it wouldn't surprise me if a giant water bug eventually found a soft membrane on a beetle leg and sucked the beetle dry. The mouthparts of water beetles are probably too small to damage the water bugs. In other words, a true bug aquarium is an armed camp with the giant water bugs being the meanest; they are likely to be the only ones to survive. I suspect that the five-legged giant water bug will eventually be eaten as it has limited abilities to maneuver, fight off attack, and has a large area susceptible to being bitten. If you want to keep it, put it in a different tank.

 

Phil Nixon

[Betta132]

One of the backswimmers killed the smaller of the toebiters. Not too surprising. Removed all but one backswimmer, a juvenile with its armor not yet developed. This leaves me with a roughly dime-sized, five-legged toebiter, a juvenile backswimmer, and a few snails. The snails are water quality alarms- if I see them bailing out, I have a problem.

Will attempt to feed both from tweezers in a day or two. Might dump mosquito larvae in if I can find some. I assume both will take any soft-bodied animals they can nab? 

I'm pretty sure the toxin that aquatic insects inject is actually digestive acid. Backswimmer bites sure burn like it. (Didn't know two years ago that they could bite, didn't expect cute tiny bug to stab me.)

Once the toebiter grows to roughly full size, will it be safe around something like a predatory diving beetle? I assume there's a point where even an extremely slow one would be able to defend itself, and this one has apparently adjusted to its missing leg- it swims fast.

Would one of these http://www.microcosm...gs2/ranatra.htmbe safe? Doesn't look like there are many vulnerable bits, and I'm not sure anything would even notice it as being edible. 

How compatible are giant water bugs? If they're the same size, will they attack each other or just end up in a tolerable standoff? 

How much space does one of these guys really need? Could I theoretically divide the tank and keep separate critters? 

[gerald]

Ranatra are slow and not very strong.  I suspect giant water bugs and large diving beetles could kill them.

[Betta132]

Good to know. 

 

I tried feeding them bloodworms impaled on the tip of a small needle. The backswimmer immediately grabbed one and swam off to eat, while the toebiter seemed frightened of the bloodworm. I tried again, and it grabbed the worm but dropped it again. I left a couple bloodworms in the tank, one floating and one sunk, to see if the biter might grab one that it runs into. I'll pull them out in a few hours if not. 

Will try a larger piece of food for the biter tomorrow in case that's the issue. I may have just made it nervous the first time, it still panics if I move too fast near it. 

At what point do I need to be concerned about the toebiter not eating? 

[9darlingcalvi]

It might have to eat live minnows like they do in the wild...

[gzeiger]

Live mosquitos or bloodworms should be good. They are definitely in season now even in the frozen north.

[Betta132]

I'll go looking for some, or just set a bucket full of water in the yard with some leaves in it. 

Any idea how long it might take this guy to stop panicking every time it sees me? 

[gerald]

Have you tried offering toes? 

[Betta132]

I'd rather not, they make very expensive food and I need the ones I have. 

Tub of aquarium water is now in a very mosquito-y part of the yard. There are probably eggs in it already, so I should have some edible-sized larvae in a few days.

[gzeiger]

You should pick out a couple egg cases and stick them in the aquarium directly. Not sure how that would turn out, but it would be interesting to know.