Bare earth/low stream - what invertebrate activity could be observed?

[Jason Green]

Hi all,

I saw this interesting stream (the water is low, just an inch deep at this point but moves rapidly elsewhere) today on a fieldtrip, and noticed that along the 'bank' there is a lot of bare earth. Could that be from a higher water-level at some point? Anyway, are there any insects habitat-specific that I could find there this year? Emerging adult insects, solitary bee nests, etc. Just a thought...

What may I find in the area, given the low-ish water. I haven't surveyed many waterbodies and surrounding habitat for invertebrate activity before so would appreciate any help!

I'm currently using this cold weather to trawl various sites across London, looking for areas that could prove worthwhile for visiting in Spring/Summer insect-wise.

Take care,

Jason

[Dogghound]

The amount of vegetation is suggestive that this floods or is heavily trampled. Something is limiting growth. Open areas like this are great for insects such as solitary hymenoptera, and associated species like bee-flies. Also an area you would expect to find basking butterflies, dragonflies, diptera etc. Although its unlikely to have specific species unlike a similar larger area on a heath for example. What is the overall habitat of the area? anymore info about the stream?

[Jason Green]

Thanks Dan

The stream runs in a half-circle above ground and the area itself is pretty wild with a few garden escapes due to historic fly-tipping. Nearby arboreal, plenty of grassland with a good few hedgerows. Nearby there is a good standing of Fern, and generally has good insect activity. Full sun too, I'd imagine.

[diggleken]

Hi Jason,
that bank looks like a boulder clay type and has had some continuing erosion from its steepness and exposure, resulting in little green growth, plus quite cracked from sundrying, so again not a good wet area for plants, so ..........................
Invertebrates, could be colonized by green tiger beetles in dry earth and butterflies and others drying wings as its a warm area. Little chance of dragonflies with so little water I suspect, but not my area of expertise.
Just my thoughts - now youve shown us, you'll have to keep a diary!
Cheers
Ken

[Wild-Woman]

Could be a good place for Groundhoppers Jason.

[Acutipuerilis]

There are a fair few bugs that like that sort of open, disturbed habitat - look out for Nysius, Chlamydatus and various hoppers such as Eupelix cuspidata. It's often a good hunting ground for nabids such as Himacerus major too. You may well find some of the shore bugs (e.g. Saldula) along the margins of the water as well - they are usually associated with firm mud. It's always worth a good look, and you're bound to get something a little bit different there with a bit of patience.

[Jason Green]

Excellent, thanks for the help all! Some very interesting reasoning behind the bare earth. The Bee-fly (A commonly-enough encountered insect but one I still have to seek out! ), Groundhoppers and Eupelix cuspidata sound worth searching for! A Green Tiger Beetle... another good one.

As soon as the invertebrate activity steps up a gear I'll return and keep you all posted.

Thanks again!

[Paul mabbott]

As long as the water doesn't dry out entirely, I would have expected some of the more water-loving beetles especially carabids and staphylinids. You could get a good selection of Bembidion spp as well as Leistus, Agonum &c..

Difficult to sample such areas with pitfalls and other traps but laying a flat stone (slate is ideal) or piece of wood partly in the water, partly on the soil forms a good shelter for invertebrates and doesn't attract the attention of humans! Have fun.

[bigdave60dog]

To be honest it looks as if the bare earth is relatively new ground that has not had thet time to get colonised with wildlife.
There are a lots of plants and animals specific to this habitat.
Many annual wild plants as well as orchids. even the well know primrose is really adapted to live in disturbed (by moles)woodland soil.
Soliatry bees if the orientation suits them. hunting wasps. wolf spiders will sun themselves on this soil as it warms up before that covered by vegetation.
There are loads of things to watch out for.
I reckon though. That is best to dicover by experience as many of us -including me- have done.
Happy observing,
Dave

[Dogghound]

Originally Posted by Jason Green

Thanks Dan

The stream runs in a half-circle above ground and the area itself is pretty wild with a few garden escapes due to historic fly-tipping. Nearby arboreal, plenty of grassland with a good few hedgerows. Nearby there is a good standing of Fern, and generally has good insect activity. Full sun too, I'd imagine.

The main influence on these habitats are the surrounding areas, if this is the only such habitat in a larger area its unlikely you will get to many bare ground specialist (especially scarce ones). If it is linked, or part of a network of many sites the odd's increase. Being near a ford I imagen that alot of erosian takes place here from walkers and thats the main reason this bank is bare, it looks well vegetated further up. Im guessing its near farmland? this often reduces the quality of the dyke, it looks fairly poor in regards to vegetation, although is likely to be dry in summer, and its hard to say from here. Possibly through dessication from nearby tree's. Wet area's on the edge of different habitats like this naturally attract alot of insects although as I say how significant they are is dependent on the local area. I would certainally expect this to be a good area for dragonflies as well such as Aeshnids (Not breeding but hunting).