Ansie Dippenaar-Schoeman

Anna Sophia "Ansie" Dippenaar-Schoeman (born 1948) is a South African arachnologist who has made significant contributions to the study of spiders and other arachnids in Africa. She is a leading taxonomic authority on the continent's spider fauna and has been instrumental in establishing South Africa as a center for arachnological research.

Quotes

Interview with Naomi Meyer

On the publication of Field guide to spiders of South Africa by Dippenaar-Schoeman, published by LAPA Uitgewers in 2014. (LitNet. April 17, 2014)

• Did you know that on a weight basis spider silk is five times the strength of steel?

• I retired at the end of October 2013, after 46 years of service at the ARC Plant Protection Research Institute. I started in 1967 as a technical assistant and worked my way up through all the post levels to retire as a specialist scientist. However, I was reappointed at ARC-PPRI on a 2-year contract as a "retired mentor of the ARC." I have also been reappointed as extraordinary professor at the University of Pretoria for the next three years. I will continue to be involved in the South African National Survey of Arachnida, the running of the online Virtual Museum and the African Arachnida Database, and hope to continue with research on the crab spiders. I have authored more than 250 publications on spiders, which include nine handbooks and 125 scientific publications, and co-supervised 22 students from seven universities.
  • In response to "Please tell our readers about your background."

• No, most spiders are harmless and they do play a very important part in nature. We market spiders as the "Farmer’s and gardener’s best friend." Spiders are very important predators in crops and they prey on a variety of pest species. Of the more than 2,000 known species of South Africa only a few come into contact with humans and when they bite the wound might need some treatment.
  • In response to "When I see a spider, I want to kill it. Without thinking. Should I?"

• South Africa has a rich fauna of spiders, with about 2,000 known species. A variety of spiders occur in houses and outbuildings and it is inevitable that they will often come into close contact with humans. Most spiders will avoid physical contact, but when they are accidentally touched or squeezed, in self-defence they might deliver a bite. Very few spiders are potentially harmful to people. The spiders can be divided into the ones that produce neurotoxic or cytotoxic venom. The neurotoxic venom affects the nerve system and it is mainly the button spiders (widow spiders) that are the most important. They belong to the family Theridiidae genus Latrodectus and six species are known from Southern Africa. The cytotoxic venom affects the tissue around the bite site and the only spiders with cytotoxic venom so far known to be of medical importance in South Africa are the sac spiders (Cheiracanthium spp) and violin spiders (Loxosceles spp).
  • In response to "Which ones are really dangerous – and how do you know at first glance?"

• They must treat spiders with respect as spiders can bite, but spiders are amazing animals with unique behaviour, as they produce silk threads which they use for all kinds of activities. Unfortunately spiders are widely feared and much maligned, yet their natural and academic importance cannot be overstated. They compromise one of the largest groups of land animals. They are commonly found in and around houses, in gardens and on farms and are one of the more abundant types of wildlife seen on all walking trails. They are important predators in terrestrial ecosystems and for many their webs are tangible records of their complex behaviour. Spiders therefore provide children with a wonderful opportunity to study animal behaviour by using spiders for school tasks research and for school expos.
  • In response to "What should I tell my children - what should they do when they see a spider?"

• Spiders as predators play a very important role as biological control agents. Especially now, when people want crops without pesticides, spiders have a role to play. We have started the red-listing process, but it is not yet completed. The most threatened species will probably be the baboon and trapdoor spiders, which can be affected by the pet trade and habitat destruction.
  • In response to "If there are millions of spiders and spider species and they have survived since before the dinosaurs, why look after them now? Which spiders are actually endangered species?"

• In houses we find many species that are cosmopolitical, and they have moved with people all around the world. We commonly find some of the jumping spiders feeding on flies and cockroaches, the spitting spiders feeding on booklice, ant-eaters feeding on ants, rain spiders feeding on moths, the daddy long legs feeding on ants and the brown button spiders feeding on bugs. The only problem species in houses is the sac spider and in a few areas violin spiders.
  • In response to "Which spiders are good to have in or around your house?"

• Their most distinctive characteristic is their ability to produce silk. These silk threads are produced in silk glands situated in the abdomen. Silk threads are used daily in numerous ways by the spider, [e.g.] wrapping of prey, to hang from during ecdysis, to deposit sperms on before mating (sperm web), to tie the female down during mating, and egg sac construction. Silk threads are also used extensively to construct intricate traps to catch prey.
• The ability to produce venom: all spiders, except one family, produce venom to subdue or kill prey. The venom is produced by a pair of venom glands in the cephalothorax and secreted through small openings on the tip of the fang. Most spiders are polyphagous and feed on a variety of available prey; they are one of the most common predator groups found in ecosystems and have special adaptations towards a predatory way of life.
• The ability to lower their metabolism. This enables them to survive for long periods without food or water and to adapt to adverse climatic conditions. This makes them very good predators.
• A variety of defence mechanisms, such as whirling of webs, dropping of legs, playing dead, etc. are used to enable them to survive.
• They are masters in the art of camouflage and mimicking. With colour, shape and behaviour they are able to blend in with their surroundings to escape predators.
  • In response to "What are your top five most interesting facts about spiders?"

• Spiders are unique in that almost every family or genus has a different behaviour. Just looking at an orb-web that is spun every day gives you some idea of what to expect of a spider.
  • In response to "What is the meaning of [the] life … of a spider?"

Quotes about Ansie Dippenaar-Schoeman

Rudy Jocqué, Festschrift for Anna Sophia Dippenaar-Schoeman

An article in the journal African Invertebrates, Vol. 56 No. 2. (August 1, 2015)

• She was the first African biologist who graduated with a doctoral study on spider taxonomy. Later we found out that she was the first to have used pitfalls for spider studies in Africa, and had already proved the importance of these animals in biological control, long before anyone else in the world had even dreamt of it.

• She mainly told me of the many plans she had for African arachnology. Although she radiated enthusiasm, I had my doubts about the feasibility. Ansie would become the leading lady for African spider studies in the next three decades, which culminated in her election as president of the International Society of Arachnology (2004–2007), the first woman to be honoured with this position.

• If you objected with something like "Yes, nice idea but this involves identification of so many thousands of specimens," she most often reacted with "Is that all, what's the problem?"