A sawfly, aphids and a mite were among the eight species new to the UK that have been identified on the 10,000-acre (4.046.8-hectare) estate.
A biting midge feeding on a larger cranefly was also observed during the survey that was made in 2012.
This behaviour had not previously been recorded in Europe, according to the estate's owner, Trees for Life.
The new species recorded were the sawfly Nematus pravus and Cinara smolandiae, an aphid.
Also recorded were two species of aphid parasitoids - Ephedrus helleni and Praon cavariellae - and three species of fungus gnats called Brevicornu parafennicum, Mycomya disa and Sceptonia longisetosa.
Ceratozetella thienemanni, a mite, was also recorded.
Trees for Life's executive director, Alan Watson Featherstone, observed the midge feeding on the cranefly.
He said: "The surprisingly rich variety of life at Dundreggan highlights the vital importance of conservation work and of protecting and enhancing habitats across the Highlands.
"The discoveries are not only demonstrating that the estate is a special site for biological diversity - they are also revealing that there is still much to learn about Scotland's biodiversity."
Species of bugs not previously recorded in the UK have been found on Dundreggan Estate near Loch Ness.