Finding renosterveld treasures in unexpected places

Finding renosterveld treasures in unexpected places

By Odette Curtis-Scott

Unlike many of the flashier vegetation types (like forests or fynbos), renosterveld shrublands tend to look extremely drab and lifeless during the peak summer season. This is because the peak flowering season happens over spring and because summer in the Western Cape tends to be dry, hot and windy.

Above: Crimsonspeckle Footman (Utetheisa pulchella). Photo by Odette Curtis-Scott

So when I visited a small (10ha) patch of renosterveld near Caledon in the height of summer, I did not expect to find much at all. The vegetation was so dry that is almost looked like it had been sprayed with herbicide (it hadn’t been!), the little patches of Rooigras (Themeda triandra) were grey and wilting and everything was crispy and desiccated. There were literally only two species flowering: Crassula tetragona with its succulent leaves and tiny white clusters of flowerheads, and Metalasia acuta, an unassuming, spiky, grey-green shrub. The latter belongs to the Asteraceae or Daisy family, although like so many renosterveld ‘daisies’, it holds its tiny flowers in tight clusters that certainly do not resemble the typical daisy familiar to most, until viewed through a macro lens or similar apparatus.

As I walked past a cluster of Metalasia, I disturbed large numbers of white moths, which quickly settled again and turned out to be the very attractive Utetheisia pulchella or the Crimson-speckled Footman. Because they were so plentiful, I decided to sit next to one of the Metalasias and see if I could see any other pollinators or their predators.

Above: Physocephala. Photo by Odette Curtis-Scott

The world that revealed itself kept me glued to that spot for nearly two hours!

The first thing I looked for were any moths that were not flushed by my initial disturbance and appeared to be attached to the plant, indicating they might be in the grasp of a predator. To my luck (but not the moth’s, of course), I found a Footman being subdued by a very attractive and ridiculously well-camouflaged Praying Mantis in the genus Miomantis.

While photographing the mantis, a moving stick caught my eye and there was a pale-coloured, Short-horn Walkingstick Parabacillus, so perfectly camouflaged in the light, yellowing vegetation. As the moths and other insects grew used to my presence, more pollinators visited the flowers, some being more obliging for the camera than others. In the mix were several solitary bees and wasps, a couple of butterflies, a Bee Fly (in the family with the lovely name of Bombylliidae) and a most interesting Thick-headed Fly which appears to be a wasp-mimic.

Above: Spectacular Crab Spider (Thomisus spectabilis). Photo by Odette Curtis-Scott

A tiny Spectacular Crab Spider Thomisus spectabilis also made a brief appearance when moved off her post at the top of a flower where she had been anticipating a surprise attack on an unsuspecting pollinator (crab spiders can take prey significantly larger than themselves and often prey on bees).

However, the find of the day (in fact, it counts amongst my ‘finds of a lifetime’) was the most beautiful invertebrate I have ever laid eyes on: A Rainbow Cuckoo Wasp.

With stripes comprising every colour of the rainbow in an iridescent, jewel-like shimmer, a little Rainbow Cuckoo Wasp (Chrysis sp., smaller than a Honeybee) made an appearance and took my breath away. In this dry, tiny remnant of renosterveld, surrounded by fields monoculture currently lying barren after last year’s harvest, this little treasure was a completely unexpected treat.

Above: Rainbow Cuckoo Wasp (Chrysis mionii). Photo by Odette Curtis-Scott

Not only did he (I am calling him a male, as there was no sign of an ovipositor, an egg-laying appendage found at the end of the abdomen) pose for some lovely photos, but he also nonchalantly spent about an hour coming and going from the site – hence my unwillingness to get back in my car and head back to the office. I was also grateful for his unperturbed, repeated visits as my first photos were rather blurry due to my excitement! He visited flower after flower, while I soaked up the beautiful scene in the baking sun and snapped away happily with my Canon.

A dream come true

I have dreamed of finding one of these in the renosterveld ever since seeing it in the Field Guide to Insects of South Africa (Mike Picker and co); an embossed photograph of the same / similar species occurs on the cover of the third edition of this wonderful book.

Cuckoo wasps are not uncommon in South Africa, but they are most active in the hottest, driest times, which coincide with what we have always considered the ‘deadest’ time to visit renosterveld, thus there are very few records of them on iNaturalist from renosterveld. But no ecosystem is ever ‘dead’, its biodiversity is just less obvious or active. I had seen other smaller, less obliging cuckoo wasps the previous spring, but never one as large or colourful as this one.

Above: Common Blue Complex (Complex Leptotes pirithous). Photo by Odette Curtis-Scott

Lesson learnt: Renosterveld, even at its driest and least attractive times, can still harbour exquisite, unfamiliar surprises, they just take more time to reveal themselves. With patience, one will eventually be rewarded with these treasures.

** A big thank you to iNaturalist experts for assisting with IDs for the insects.