Avontuur Sustainable Agriculture

Monthly Archives: October 2015

Water Beetles

On the 5th and 6th of October Dr David T Bilton from Plymouth University in the United Kingdom visited Avontuur. David is an Associate Professor and Reader in Aquatic Biology at the Marine Biology & Ecology Research Centre in the Faculty of Science and Engineering at the University. He was accompanied by his colleagues Dr Stacy DeAmicis and Dr Andy Foggo.

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Dr David Bilton collecting beetle samples from a standing water body along the Grasberg River

David has a longstanding interest in water beetles. He has travelled widely in Africa, the UK, the Middle East and in continental Europe, studying and sampling these fascinating water organisms. In South Africa he has been doing fieldwork since 2008, working mostly in the Western Cape, where lots of the beetle he finds are new to science. His visit to the Matsikammaberg last year produced 4 new species, for example, three of which are only known from this mountain. He is hoping the Bokkeveld may render some interesting water organisms too. Other sites he has sampled at are the Injisuthi area in the KZN Drakensberg, the Cape Peninsula and parts of the Cederberg in the Western Cape and, more recently, the Bokkeveld and Hantam plateaus in the Northern Cape.

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These are the tools used to search for and catch beetles in water bodies. The beetles vary in size so the catching nets also vary.

There are approximately 13 000 species of true water beetles known throughout the world, but the real number out there is probably closer to 20 000. Water beetle is a generalized name for any beetle living in water at any point in its life cycle, and beetles have colonised water around 20 times from different terrestrial ancestors during the course of their evolution. Most water beetles can only live in fresh water, with a few marine species that live in the littoral zone, although they also represent an important part of the fauna of salt lakes and pans as well as inland salt rivers. From David’s long involvement in studying these fascinating organisms he has observed many interesting lineages I here in South Africa, including some whose closest relatives are in far away places like Europe and Australia, rather than other parts of Africa. This goes to show why it is so important for these fresh water invertebrates to be studied.

We are looking forward to seeing the list of species that were sampled in Avontuur and to know if there are any new ones and perhaps learn more about their relatives from around the world.

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The team also found time for some sight-seeing. A walk to Kromvlei and the escarpment was a delight.

 

Amsinckia spp. Eradication Research Experiment on Avontuur

Conducted by EMG team: Areefa Tietis, Cynthia Coetzee, André Van Wyk

Lead researcher Siya Myeza.

Supervised by: Noel Oettle

Start date: 22 September 2014

Amsinckia is an invasive alien herbaceous plant that thrives in disturbed and more fertile areas. It is winter growing and flowers and sets seed in the spring months of August and September, and with the seed maturing in October. Its presence is undesirable because it is invasive and thus displaces indigenous plants, and it is unpalatable for livestock, especially later in the spring when its hairy leaves irritate the mouths of grazing animals. Its thorny seed pods are readily transported and distributed in the wool of sheep.

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Amsinckia spp. hand removed by uprooting in one of the plots and left as a mulch. Uprooting is the management strategy generally used in the infested areas, and as a result of the initial findings of the research most uprooted plants were composted in 2015.

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