The insect collection contains over 120,000 specimens and represents over two thirds of species so far recorded in the United Kingdom. The collection is acknowledged as an important regional resource for reference and scientific study. Many families in the major orders of British insects are represented in the collection which include beetles, flies, bees, wasps, ants, butterflies, moths, bugs, dragonflies and grasshoppers.

The British insect collection is based on the individual collections of K G Blair, R J Dickson, A Dobson, C H Dixon, B Goater, S J Grove, P Holloway, I R Hudson, J F Marshall, E Neal, B J Pinchen, G B Prior, H D Swain and others. There are also regular deposits of voucher material by researchers undertaking entomological surveys within Hampshire.

More than 1,150 fluid-preserved British spiders with data make up the collection. As yet the collection has not been fully analysed and we are unsure how many of the 600 or so British species are present.

A relatively small collection of mostly spirit preserved British marine, freshwater and terrestrial invertebrates. Crustaceans (crabs and shrimps), echinoderms (sea urchins and& starfish), myriapods (centipedes and millipedes), coelenterates (sea anemonies, corals, hydroids and jellyfish), tunicates (sea squirts) and annelids (worms) are all represented. Most of the material has been collected by museum staff. The R Wells collection of marine invertebrates is the only named collection.

Invertebrate specimens with good supporting data provide evidence for the occurrence of a species at a particular place and time. These specimens can tell us about the environment at this time and thus may provide important data for long-term analysis.