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One of the main functions of the Museum research departments is augmenting our unique research collections by undertaking field-work. During August-September 2005 I travelled to Namaqualand in the Northern Cape to sample insects for the Museum.
Why travel all the way to Namaqualand to catch bugs? There are many reasons.
First, it ensures that our collections are not biased to KwaZulu-Natal alone, but take in the biodiversity of the whole country. Many of the insects that occur in the Northern Cape are not found in KZN and so fieldwork like this ensures a comprehensive coverage when our scientists, research associates and other colleagues come to revise the various insect groups.
Second, the insects that occur in Namaqualand have particular relevance to many of the research projects that have been undertaken in the Arthropoda Department. With reference to myself, Namaqualand is an acknowledged 'hot-spot' for bees. That is to say, bees are especially common and diversified in that region as opposed to elsewhere in the country.
The bees that are the subject of my Masters research are mainly localized to Namaqualand, and it was important for me to see them first-hand.
One of the highlights of Namaqualand are the spring flowers. These eye-catching, fragrant carpets of flowers alive with the hum of bees and other insects draw tourists from around the world. Such 'blommetjie-tourism' represents one of the principal economic dynamos for the economically-depressed Northern Cape, generating hundreds of thousands of rands per year. This vital natural resource is maintained largely thanks to the pollinating activities of bees, flies and other insects.
Should these pollinators disappear, the flowers would disappear too and with them the numerous hotels, guest-houses and tour operators that depend on this nunu-nurtured resource. In real terms bees and flies are important for the economic livelihood of Namaqualand.
Namaqualand is also interesting for the study of biogeography, which is the scientific study of why animals occur where they do and how their distribution ranges have fluctuated over time. We have abundant evidence from palaeontology (fossil crocodiles, fossil woods etc.) and geology that indicates that the Namib and Namaqualand was much wetter in the early Miocene (about 17 million years ago) with summer rainfall. Around this time the ice caps in Antarctica developed to continental proportions and greatly influenced global climate, especially strengthening the cold Benguella Current.
This increased aridity in the Northern Cape, and change from summer to winter rainfall must have had a profound impact on the nunus of the region? some would have gone extinct, others would have evolved to the new, dry conditions and yet others would have clung on in tiny, moist refuges in the dissected Namaqualand escarpment.
Excitingly, we have evidence of flies (e.g. certain species of blepharicerids, athericids, empidids, psychodids, rhagionids), some beetles and other insect groups (e.g. stoneflies) that fall into this last 'relict' category. These 'refuges' provide us with living clues to the past. Several of these 'relict' flies have been described by Natal Museum staff, and elucidation of their evolutionary relationships has shown that their nearest relatives live in moist grasslands and fynbos in Western Cape and KwaZulu-Natal Drakensberg.
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It was exciting to come across a mantophasmatid or rock-crawler during the field trip. These small, wingless, rather unattractive goggas look like a cross between a praying mantis and grasshopper, and they caused a riot in the insect world when they were discovered a few years ago. They were placed in their own Order, the first to be described since 1914.
A discovery of this magnitude is exceptionally unusual, and it is difficult to convey the enormity of the discovery to non-entomologists, but it would be analogous to finding that a Loch Ness Monster had been happily swimming around Midmar Dam for years with no-one noticing.
Ironically fieldwork by entomologists from Cape Town University has now shown mantophasmatids to be fairly common in the Western and Northern Cape. The discovery does, however, raise the alluring thought of what else may be hiding out in the wide open spaces of Namaqualand!
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