Fonseca's seed fly is on the nation's Biodiversity Action Plan but a paper by Scottish Natural Heritage (SNH) highlights just how limited the insect's world is thought to be. Experts believe the fly, Botanophila fonsecai, is restricted to a 328-feet long strip of land on the north shore of the Dornoch Firth.
The population is small and is subject to environmental changes, while its beach habitat is frequently being trampled by humans taking part in recreational activities on the beach.
"Consequently, B. fonsecai is particularly susceptible to extinction," SNH scientists say.
In 2010 Botanophila fonsecai was found at four sites: Dornoch Point, Dornoch Sands, Dornoch north dunes and Embo dunes.
Compared to collection data from the 1970s and 1980s, populations were low, which could be interpreted as decline, a missed peak of activity or normal population variability.
No host plants could be found. But, four specimens seemed to be associated with bare sand in lyme grass.
While it has never been found elsewhere, SNH thinks there are expanses of dunes on the east and north coast of Scotland that may harbour the species.
These include: other beach sites on the east of Sutherland; from Keiss Links north of Wick along the north coast to Durness; along the Moray Firth coast including Culbin Dunes, Whiteness Head and Findhorn; the dunes from Lossiemouth to Aberdeen and Aberdeen southwards.