Hi Les, from the look of it, the last two images are of a Chironomus Midge, possibly Luridus, s fairly common and non biting! The humped thorax is a characteristic, and in this case a male because of the large and feathery antennae.
Nice macro
The other two, Les, are an Azure Damselfly and a Green-veined White butterfly.
I especially like #2
What is the definition of parasite, Les?
All insects can have some form of parasite activity, which causes actual harm to the host; but what is quite common are little mites which attach themselves to larger insects and get transported around. Some are quite harmless unless the infestation becomes too large, as can sometimes be found with bees.
I think, if I remember correctly, some of those little mites go under the name of Phoretic Mites (or something like that) but it is a very specialised subject and as far as possible I tend to keep away from this complicated group.
You often see little brown or bright red mites on insects. Some people think the red ones are bloodsuckers, along with the Velvet Mites which are often found in gardens but they are harmless, although some can damage crops.
The real bloodsuckers are the ticks.