Nearly forty years ago, in 1966 and 1967 to be precise, members of two expeditions from the Belgian “Museė Royal de l’Afrique Centrale” made an exhaustive study of the invertebrates of St Helena. Previous to this there had been studies of some groups, most notably by J C Melliss, Thomas and Edith Wollaston and Arthur Loveridge. The Belgians’ results were published in their museum journal during the following years, some in English and others in German or French. An analysis of these publications has enabled us to calculate that out of about 1037 invertebrate species described from St Helena (excluding fossils), about 400 are endemic. This is in contrast to the much younger island of Ascension, where less than 30 endemic species are known.

Whilst the endemic plants of St Helena and the Wirebird (an endemic plover) have been much studied during recent decades, attention to the invertebrates has been minimal. Admittedly such flagship species as the giant earwig and giant ground beetle have been highlighted, due primarily to the work of Paul Pearce-Kelly of London Zoo, but neither of these conspicuous species has been seen during the last 46 years. Most of the other endemic invertebrates have been ignored. Invertebrates are much harder to study than plants. Very few stand still. Most are hard to identify in the field, and anyway are so small that a microscope is necessary. Guides and descriptions may be in languages other than English, and are often full of taxonomists’ jargon and in obscure publications. Popular books are often geographically based and give scant attention to rare species while specialist books are hard to find. Added to this, invertebrate specialists usually concentrate on their “own” group, and do not attempt to identify rare species from other groups. It is not surprising that most people stick to plants. Most of the endemic invertebrates of St Helena have been found in the humid high part of the island where there are remnants of the endemic vegetation. However, on Prosperous Bay Plain, in the arid area in the east of the island, some 55 endemic species have been found. More than 20 of these have been found only here and nowhere else on the island, and this is precisely the area where it is proposed to build an airport.

This is why we have been asked by the St Helena Government to make a study of the invertebrates of the area concerned. We are delighted to be back in St Helena, and to be working in an area that holds a particular fascination for us. We have started by studying the sites that were sampled so long ago by the Belgians, as closely as we can identify them. This should give us a reasonable idea of how many of these endemic invertebrates survive. They already have human-induced problems to contend with, including predatory introduced animals (e.g. mice, a large centipede and scorpions) and also collecting by homebuilders of the loose surface rocks that provide crucial shelter for animals in this hot climate. Although these problems all existed four decades ago it seems likely that eventually they will take their toll of some endemic species. When we have studied these sites we will extend our work to nearby areas that are not likely to be disturbed by airport construction. In this way we hope to be able to ascertain if there are other areas where this unique assemblage of endemics can survive more or less intact. We will be working here for three months, and during that time hope to be able to give a training opportunity to interested Saints who might be able to take the work forward as necessary after we leave. We will produce an interim report when we leave but our final report will be later and will depend on input from many specialists in the various groups of invertebrates. This will then form part of the Environmental Impact Assessment relating to the airport. Don’t hold your breath for rediscovery of the Giant Earwig – our best guess is that it is extinct! Ref: St Helena and Ascension Island: a natural history.

Philip and Myrtle Ashmole (2000). Anthony Nelson, Oswestry. ISBN 0 904614611

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