Observed by foxyfoxy’s reputation in Invertebratesfoxy’s reputation in Invertebratesfoxy’s reputation in Invertebratesfoxy’s reputation in Invertebrates on 2nd February 2010

A 10-12mm long wingless insect that skimmed the still water with ease.It appeared to be hunting other smaller insects.

Species interactions

No interactions present.

Other observations of Water Cricket (Velia caprai)


This carnivorous bug is an

This carnivorous bug is an interesting spot. I think V. caprai is the most likely ID, but there is another very similar species, V. saulii, and I don't think this can be easily distinguished from photos (you need to look at details of the female abdomen). However, V. caprai is more common and widespread - (I'm not even certain the other species is found in Ireland).

Rob Coleman

V. caprai or saulii

I agree - a good spot and it's much more likely to be caprai, but hard to confirm from the photo as saulii was added to the Irish list in 1977 though it remains rare.

What a great spot! I have

What a great spot! I have never seen one of these, but will look out for them now. I see from the map that they are widespread.

Open University - Biodiversity Observatory

It is a male, which makes it

It is a male, which makes it harder to identify. The dark marks down the rim of the abdomen are supposed to be more triangular in caprai, and they look triangular in the photo.

They are more often on running water than still.

Water cricket

Thanks for all your comments,I spotted this fellow while checking to see if frogs were spawning at this site as they do every year at this time,it moved incredibly fast, but because of my torch other water surface insects gathered and the cricket tried to pounce on them.
Is it nocturnal?,this water is only 20-30cm deep and the nearest flowing water is about 100meters away ,behind hedges and across a road, not connected in any way to this water.
I havn"t found a site that has information about Irish inverterbrates so I have no data on most of my spots other than my reference books which are general in nature any ideas?
P.S no frogs spawning or any seen since before the big freeze .

regards foxy


Irish invertebrates


Thanks very much,I will be visiting it often.



water crickets

Great photos Foxy, these secretive and fast-moving insects are hard to see let alone photograph! Agree with the above comments that V. caprai is the most likely species, but I don't think we can entirely rule out V. saulii from the photo. Females are slightly easier to ID, but would ideally need close-ups from above and from the side.

According to the national atlas of water bugs (see http://is.gd/7TjFp - gives maps for Britain but not Ireland)), V. caprai is more often associated with water that is flowing, at least gently, while V. saulii is more likely to be found on still water, but again that is not sufficiently clear-cut to judge which species this is.

The books make no mention of this bug being especially nocturnal, but many other water bugs seem to be active by day and night. Certainly there is plenty of activity in my garden pond if I go out at night with a torch, and water bugs often turn up in moth traps, even at a distance from water.

Open University - Biodiversity Observatory

Close up"s

Hi Martin,
caught a cricket tonight and got some closeups,hope it might help to id it to V.caprai or V.saulii.




Just found another comment on V. caprai in Jonty Denton's "Water Bugs and Beetles of Surrey": "it is usually nocturnal in open situations but is regularly active by day on shady backwaters of streams".

Open University - Biodiversity Observatory

Thanks Martin

Thanks Martin,
out of curiosty I visited the same spot of water last night and today,nothing much today, but the torch drew at least 4-5 of these crickets,3 newts,the caddis larva (dragonfly larva) posted today,several spiders that walked on water,small water beetles and flies that hopped along the surface all in a puddle the size of a kitchen table!.
The newts surprised me so much I forgot to use my camera at all,I don"t see such big ones usually.




Great pictures Foxy

Beth BR

Velia caprai

Foxy, your second batch of photos (on the white background) are of a female (no spines on hind tibiae) and I think we can say that it is Velia caprai.

Open University - Biodiversity Observatory

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