[Candide]

I've put up bee hotels in various places but then looked into habits of hoverflies.  Which in turn led me to The Buzz Club which had details for making a hoverfly lagoon cos they're semi aquatic ( or some species are ).
Fits right in with allotment, make do and mend culture:  the lagoon itself can be a cut down plastic milk bottle.  I did cobble together a protective cage out of chicken wire, but only cos I got some.
Very beneficial insects to encourage - pollinates and predates it seems.
Hmm.  Can I do a link?
https://www.thebuzzclub.uk/hoverfly-lagoons
So wonder if anybody else trying this out.
Obviously a valid method of pest control as link is to a dept of University os Sussex

[Subversive_plot]

Hi Candide

We have lots of hover flies around; a pollinator you see especially in the spring, sometimes more often than honey bees!  It's a good thing to build something that attracts them.

We have honeybees, but here they are an exotic species. 

We also have lots of bees around here that are not honeybees.  Orchard mason bees are good, and easy to attract by building "houses" for them.  Other bees will be attracted to similar houses.

[comfreykid]

Candide ,  thanks for posting and for the link .  l have been growing Poached Egg plants ( Limnanthes Douglasii )  as attractants for hoverflies , for pollination and as a natural predator of aphids. The lagoons sound like an excellent idea. 

[Candide]

The Professor of that dept at the university wrote a couple of books about bumble bees ... a lifetime obsession of his...which i read a couple of years ago and which opened my eyes a bit to the enormous variety of bee types.  Hoverflies I'd seen about but didn't realise that they pollinated but also predated on pests.  Churned out loads of bird boxes and bee hotels for neighbours, charity fundraising etc so a lagoon seemed like a good idea to add a beneficial buzz to the plot