Please, I wonder if anybody can help. I'm asking this on behalf of my
parents. They have recently started a compost heap, you know local
council incentive to recycle etc. I'd say they've had it 2-3 months.
They've only put fruit/veg scraps, tea bags and egg shells on it,
nothing from the garden as yet.

The insects are probably not mosquitos; more likely fruit flies or
fungus gnats. Your mention of "cover" and the description of what's
in it lead me to believe you're trying to compost in a sealed container
in smallish batches. Eventually, you will get compost that way, but
it's pretty stinky because the anaerobic bacteria are doing a lot of work.

There are a number of ways to compost. Probably most suitable for a
single household's kitchen scraps is a worm bin:
http://yucky.kids.discovery.com/flas.../pg000223.html

Traditional hot composting involves enough mass to get the compost up to
temperature... in my experience that's about a one meter cube, probably
too much for what your kitchen is producing. If you do it that way,
keep the compost turned so oxygen can get into the center -- you'll get
nice compost with little or no stinkiness. If compost heats to a
high enough temp, it also kills weed seeds, plant diseases, etc.

A third option is to simply dig a shallow trench in between rows of plantings,
drop the scraps in the trench and cover. I find in our climate (which is
similar to the climate of southern England), about a one year rotation to
get back to the same spot for digging a new trench works perfectly.

Kay

Kay