Is it dangerous? Q A

NIEK COETZEE from Alberton writes: I came across this spider and couldn’t identify it. Is it venomous?

Entomologist DUNCAN MACFADYEN says: This is the beautifully marked brown button spider. It looks similar to the black button spider, but the two can easily be differentiated by looking for the obvious red hourglass on the abdomen of the black specimen – it’s the only marking on the spider’s otherwise dark body. The brown button spider has much more varied colouration, and more detailed markings. This species is commonly found in built-up areas, usually outside houses. They make their webs in dark areas, such as under windowsills. The spider is venomous. It produces a neurotoxic venom that can affect the nervous system, but the reaction is usually restricted to the bite site and symptoms clear up within a day or two. The black button spider has similar venom but it’s three to four times more potent.

AEntomologist DUNCAN MACFADYEN says: This is a darkling beetle, which belongs to the family Tenebrionidae, of which there are many species including the toktokkie. This particular specimen is heavily infested with mites, which are feeding off the haemolymph (blood) of the beetle. The mites usually don’t kill their host, but they do affect the insect’s general health, decreasing its immunity. They won’t transfer to vertebrates, however, which is good for us!