Aquatic insects

[Stylopidae]

Does anyone have any info on rearing backswimmers (either Anisops sp. or Notonecta sp.), cryptic water scorpions (Ranatra sp.), and predacious diving beetles?

 

[Dark Raptor]

I've kept Dytiscidae and Hydrophilidae beetles, some "true bugs" Nepa cinerea.
Check latin names in "search" you should find some posts about that.

http://www.arachnoboards.com/ab/showthread.php?t=43282
http://www.arachnoboards.com/ab/showthread.php?t=38258

The last thread is very long... but you shuold find information you want about diving beetles.

 

[Stylopidae]

Thanks for the threads Dark Raptor. It answered all my questions about the diving beetles except for one: What do I do with the pupae?

I'm still in the dark about the rantra and the backswimmers.

The backswimmers are an acquatic version of Platymeris almost.

Here's a pic: http://rds.yahoo.com/S=96062883/K=b...8019/*-http://www.glaucus.org.uk/pond6038.jpg

 

[Dark Raptor]

Thanks for the threads Dark Raptor. It answered all my questions about the diving beetles except for one: What do I do with the pupae?

I can help you with diving beetles.

In nature they pupate in humid soil (on land). When you see that large larvae try to escape from the aquarium, you should move them to the new box with humid garden soil. They will burrow and build pupation chamber. After 2 - 3 weeks you will have new beetles.

I've never tried to breed species like Notonecta, but the only reason is that I don't like these "true bugs". They can bite you and it really hurts :evil:
I think you can give them small invertebrates as food (they should "swim" on the surface and will be quickly captured).

 

[Wade]

The book I mentioned in the Giant Water Bug thread includes rearing information for backswimmers and waterscorpions.

I've had both Ranatra and backswimmers reproduce in aquariums. Ranatra lays eggs on emergent structure like driftwood, corkbark or in muddy substrate that's above the water line. I've had backswimmers (no idea what species) lay eggs on plants underwater which hatch out into tiny nymphs. In both cases, this was in community aquariums, so the hatchlings invariably got picked off by by the diving beetles etc that were in there too.

Backswimmers will also eat flaked fishfood in adition to live prey. Ranatra needs live prey, but I've had some luck giving them small crickets off of very fine tweezers. Red wigglers and other worms are also a good choice.

Wade

 

[dtknow]

While we are on this subject has anyone bred waterstriders before? I collected a few and caught 2 mating yesterday.

They seem to be doing quite well in the current housing which is simply a ten gallon tank with water. Throw in moths or any other little bugs for them to eat.

 

[Wade]

They'll need some sort of emergent plants to lay eggs, but apparently all stages can be reared together. Again, check out the book "Assassins, Waterscorpions. and Other True Bugs: Care and Culture" available at www.elytaandantenna.com

Wade

 

[Wade]

Here's a picture I forgot about featuring Ranatra laying eggs. Kind of blurry, but you can see what's going on! It was taken by LHP in a tank I had set up a year or so ago.

Wade

 

[orcrist]

Back when this one was alive, I kept her in a giant pretzel jar. Really Giant pretzel jar. Anyway, some vegetation was overgrowing the tank so I stuck a big bullfrog tadpole in the tank with it to nibble on the algae. The tadpole was at least 3" long. One morning I woke up to find the dead 3 inch tadpole being munched on by the 1 inch beetle.

Lesson, if it doesn't eat the beetle, the beetle will eat it.

-0rcrist

 

[Stylopidae]

Would it be correct to assume that appropriately sized mealworms would work for the tiger beetle larvae/ bug nymphs?

 

[Dark Raptor]

Would it be correct to assume that appropriately sized mealworms would work for the tiger beetle larvae/ bug nymphs?

I give my tiger beetles larvae (Cicindellidae) only mealworms and adult bean beetles (Acanthoscelides obtectus). I thinks taht it works, becase they are still alive (since May/June).

 

[Wade]

I think Evil Cheshire is talking about the dytiscid larvae, which are often called "water tigers" in the US.

Wade

 

[Dark Raptor]

I think Evil Cheshire is talking about the dytiscid larvae, which are often called "water tigers" in the US.

Ok. I got it. I've check it with my book where Cicindelidae (now subfamily in Carabidae family) are called "tiger beetles".

But my answer will be almost the same I've been feeding dytiscid larvae with mealworms and crickets. They were very good food source. Almost all larvae I had, successfully pupated.

 

[Stylopidae]

I was also referring to beetle larvae, the giant water bug larvae as well as the backswimmer larvae. I'd prefer to avoid fish food because I have a large supply of mealworms.

I have three four gallon tubs full of mealworms. I plan to have twelve by spring. One is already well established and has thousands of the buggers. I'm trying to seed the other ones now so I'll have some at each size I want.

Since I'd probably just keep the backswimmers and giant water bugs in individual deli cups to avoid filter related fatalities would changing the water once every other to once every three days be too stressful?

Reading through the websites and forum (I will buy the book, I promise) I see that the nymphs need something to attatch to when molting. Could I keep a twig in with them?

Edit: Sorry, DR. Tiger beetles and diving beetles momentarily switched places in my mind.

 

[dtknow]

Another thing, how good are Ranatra or the other water bugs at capturing fish? I have lots of feeder guppies running around with no real use...and also bullfrog tadpoles in the pond(invasive species in CA) which I dispose of.

Is anyone in the position to be able to find any Ranatra locally? While I'm pretty sure they have to be around me somewhere so far no dice on them.

 

[Wade]

I was also referring to beetle larvae, the giant water bug larvae as well as the backswimmer larvae.

Giant water bugs, backswimmers, waterscorpions etc are all true bugs and do not have a larval stage. The immatures are known as nymphs and look like mini adults, only without wings. Some authors have taken to refering to all immature insects as "larvae", but most people still use "nymph" for the sake of clarity. Sometimes, immature aquatic insects are also called "niads" in some books.

Since I'd probably just keep the backswimmers and giant water bugs in individual deli cups to avoid filter related fatalities would changing the water once every other to once every three days be too stressful?

Reading through the websites and forum (I will buy the book, I promise) I see that the nymphs need something to attatch to when molting. Could I keep a twig in with them?

That's pretty much the way most people rear water bugs and waterscorpions anyway. These animals will canibalize, especially in the immature stages. As adults, they can usually be kept together.

Avoid using a freshly cut twig, or even one on the ground. These could leach harmful tannins into the water. Waterlogged twigs collected from a pond or stream would be fine, since anything harmful should already be leeched out. Better still, use a live plant of some sort. Java moss (popular in aquarium stores) is a good one to use. A pinch of it in a small cup is enough to provide structure for milting, resting etc. It has the added benefit of absorbing ammonia, which is always an issue in unfilterd water. It doesn't need much light, ambiant room light is usually enough. The popular aquarium plant anacharis may also work, although it needs a bit more light.

Although structure is important, too much can get in the way of the molting process. You want there to be just enough for the bug to cling to and rest on, but there should be plenty of open space in the cup as well.

If you do decide to use filtered tanks later on, try using air-powered sponge or undergravel filters. These do not pose the same dangers as the electric-powered filters and can usually be used safely.


Wade

 

[galeogirl]

Great info, thanks all.

 

[dtknow]

An update on the water striders.

It appears that I have eggs. At least I have not seen these things before and they are the correct shape.

Around 3mm(guess) and shaped like a rounded off grain of rice. No stalk or anything like how Ranatra have their eggs. They are in the corners of the tank both above and below water in groups but they look like they were laid seperately. Some of them have a pair of spots near the top which I can only guess would be the eyes of the babies.

 

[Stylopidae]

Keep us posted on how you raise those. I'm interested in seeing the outcome of your experiment.

 

[dtknow]

Can anyone confirm these to be Gerris sp. eggs?

After a day the darkened to this point...note the ones under the water too...

Here they are mating again. Female has a male on her almost 24/7

Evil C.: If they hatch, I'll keep you updated.