There is a wealth of spiders in the Garden but they are usually unnoticed as many of them are tiny and very well camouflaged. The bulbous bodied comb-footed spiders are more active at night. The huge, strong webs of the golden orb-web spiders are especially beautiful when decorated with dewdrops and glinting in the sun. The bundled nest of leaves and silk made by the rain spider is common. These spiders are often the prey of spider-hunting wasps which lay an egg on each paralysed spider they catch, providing food for the wasp larva when it hatches. Bark spiders blend so well into their surroundings that it is a really fortunate person who gets to spot one. Flower crab spiders are coloured to match the flowers they sit on and wait for prey, which is often much bigger than themselves.
Insect life is plentiful and incredibly varied, from the huge carpenter bee, which has carved the tunnels into the large pole at the entrance building, to the much smaller Cape honeybee which provides very important pollination services to both wild flowers and many agricultural crops in the nearby fruit growing region.
Monkey beetles seem to especially love the daisy flowers and can often be found, back legs sticking out, buried head first amongst the disk florets in search of pollen. When the large umbrella shaped heads of the mountain celery, Notobubon capense, are in flower they are visited by various flies, net-winged beetles, bright metallic long-horned beetles and a host of other insects.
The fascinating nests of potter wasps can be seen decorating buildings in the Garden and woe betide anyone who approaches the edifice of linked hexagonal cells constructed by the paper wasps too closely.
Another nest to be careful not to touch is that of the large cocktail ant. This cardboard castle attached to plant branches houses hundreds of ants who will immediately defend it, painfully biting anything or anyone unwise enough to be a threat. Some of the indigenous ants play an extremely important role in the fynbos and it is estimated that about a third of the plant species in the fynbos are reliant on ants to bury their seeds, thus preventing them being eaten by rodents or birds or being burned by fires.
In summer the dragonflies and damselflies add colour and movement above the serene surfaces of the water bodies. So far a total of 11 dragonfly and damselfly species have been identified in the Garden and, with additional study, more are sure to be found. (See list below)
Dragonfly and damselfly list for Harold Porter National Botanical Garden
(* = endemic to South Africa)
Long skimmer – Anax tristis
Julia skimmer – Orthetrum julia capicola
*Little scarlet – Crocothemis sanguinolenta
Orange emperor – Anax speratus
Stream hawker – Aeshna subpupillata
Cape sprite – Pseudagrion furcigerum
Common bluetail – Ischnura senegalensis
Conspicuous malachite – Chlorolestes conspicuous
*Rock malachite – Ecchlorolestes peringueyi
*Sooty threadtail – Elattoneura frennulata
*White malachite – Chlorolestes umbratus