What a great picture Ilona - very good capture !

I can't suggest any insect repellant - sorry.  They all seem pretty ineffectual only lasting a very limted time.

I go looking for butterflies and dragonflies early morning - they are less active then, and so are the biters.   

 

And every one said, 'If we only live,
We too will go to sea in a Sieve,---
To the hills of the Chankly Bore!'
Far and few, far and few, Are the lands where the Jumblies live;
Their heads are green, and their hands are blue, And they went to sea in a Sieve.

Edward Lear
http://www.nonsenselit.org/Lear/ns/jumblies.html