The fearsome Highland midge is expected to start terrorising hikers and others taking part in outdoor pursuits from the middle of this week.
The recent spell of warm weather, followed by rain which is forecast from Tuesday, will provide ideal conditions for the voracious insects to start emerging.
A spokesman for Advanced Pest Solutions, which runs the Midge Forecast, based on catches from traps across Scotland and the general weather forecast, said: “It has been very warm, with overnight temperatures well over 10C.
“However, if the forecast is correct, we would expect to see significant numbers during the latter part of the week.”
“They started emerging in southern Ireland last week and tend to reach Scotland about a week later.
“And the conditions look as though they are going to be perfect for them.”
He added that midges were likely to appear in the Galloway hills and Argyll first, then Lochaber and gradually spread north.
He said: “When the data from our traps starts coming in, we will be able to start our midge forecast online.
“This will probably be during the week beginning Sunday, May 22.”
The forecast warns anyone planning to venture outdoors of the midge hot spots across Scotland each day.
Met Office forecaster Peter Sloss, based in Aberdeen, confirmed that it would rain across much of the north on Tuesday.
He said: “The heaviest rain is expected to be on Tuesday afternoon, particularly in the west, where there is likely to be about half an inch.”
There are more than 1,000 species of midges worldwide.
About 40 of these are found in Scotland, with culicoides impunctatus – also known as the Highland biting midge – notorious for leaving its mark on unsuspecting walkers.
In Scotland, midges spend the late autumn and winter as larvae, below the soil surface.
They emerge as adults in May and June the following year, with the adults laying eggs that develop quickly as the prelude to a second spate of adult midges in late July and August.
And a prolonged spell of warm, damp weather in August can lead to a third hatch in September.
