Terrestrial Invertebrates
Seventy-seven species of land snail and an estimated 14,000 species of insect live in Scotland, none of them "truly" endemic. These include Pardosa lugubris, a species of wolf spider first found in the UK in 2000 at Abernethy Forest nature reserve, and the Scottish Wood Ant. These ants, which are the most numerous residents of the Caledonian pine forest, build mounds from the pine cones and needles they find on the forest floor and may inhabit the mounds for decades. A single colony may collect 100,000 insects a day to feed its half million citizens and produce up to 250 kilograms (550 lb) of honeydew per season.
In addition to the Scottish Wood Ant, several Scottish species of invertebrate exist that are otherwise rare in the UK and important enough to have a specific "Action Plan" to provide protection. These are five species of ant and bee, six moths and butterfly, five flies and a single beetle (the Reed Beetle) and snail (the Round-mouthed Whorl Snail, Vertigo genesii). Northern Colletes is a rare species of bee, the most significant British habitat for which is in the Outer Hebrides, where there are more than ten colonies. Scotland is also the UK stronghold of the Blaeberry Bumblebee, and the Bumblebee Conservation Trust recently created the world's first sanctuary for this genus of insects at RSPB Vane Farm Nature Reserve near Loch Leven. The bumblebee Bombus jonellus var. hebridensis is endemic to the Hebrides. In 2010, a colony of the beetle Meloe brevicollis was found on the island of Coll. The species is otherwise extinct in Scotland and is also flightless, raising the question of how the colony arrived on the island. The Northern February Red Stonefly (Brachyptera putata) has recently lost its range elsewhere in Britain and is now it considered to be a Scottish endemic.
Although many species of butterfly are in decline in the UK, recent research suggests that some, such as the Pearl-bordered Fritillary, Marsh Fritillary and Chequered Skipper, which are becoming rare in the rest of the UK, are moving north into Scotland in response to climate change. In June 2008 an adult Ethmia pyrausta moth was discovered in Easter Ross. This find was only the fifth sighting since its discovery in the UK at Loch Shin in 1853, and the species has gained "almost mythical status" according to Butterfly Conservation Scotland.
The most well-known invertebrate may be a species of midge (Culicoides impunctatus), a tiny flying gnat that is the scourge of summer visitors and residents alike. Its predations result in the loss of up to 20% of summer working days in the forestry industry. Others of significance include the Pine Weevil, Black Pine Beetle, Clytra Beetle, and the Timberman, a long-horned beetle. The archaeological site at Skara Brae provided the earliest known record of the human flea, Pulex irritans in Europe.
Read more about this topic: Fauna Of Scotland