peer-reviewedThe insects are the most diverse organisms on this planet and play an essential role in ecosystem functioning, yet we know very little about them. In light of the Convention on Biological Diversity,
this paper summarises the known insect species numbers for Ireland and questions whether this is a true refl ection of our insect diversity. The total number of known species for Ireland is 11,422.
Using species accumulation curves and a comparison with the British fauna, this study shows that the Irish list is incomplete and that the actual species number is much higher. However, even with
a reasonable knowledge of the species in Ireland, insects are such speciose, small, and inconspicuous animals that it is diffi cult to assess species loss. It is impossible to know at one point in time the
number of insect species in Ireland and, although it is useful to summarise the known number of species, it is essential that biodiversity indicators, such as the Red List Index, are developed
