letting nature back in

While watching a solitary bee feeding on nectar in basil flowers in the herb patch a few weeks ago, I noticed a minute spiny flower mantid nestled down on one of the flower spikes with its spiny abdomen curled up over its back.

Over the next few days we spotted a total of six tiny spiny flower mantids (Pseudocreobotra wahlbergi) on the perennial basil bush (Ocimum basilicum sp.) and later we found one on flowers of a purple broom (Polygala virgata), which is pictured above, and then another on a rosette of leaves of a Solanum giganteum, even though the plant has finished flowering.

Above is one of the spiny flower mantid nymphs on the basil bush. The younger they are it seems more green bands are visible on the legs. As they get older they better blend in with the pinkish colours of the bracts on the basil bush’s flower spikes.

Above is an even tinier spiny flower mantid nymph showing the greener colour variation. The nymphs go through several moults to reach adulthood – seven for the females and six for males.

In order to try to show in a photograph the tiny size of the spiny flower mantid nymphs, I held a standard-size matchbox on a stick behind one of them so that the comparative size can be seen. I was most surprised when the mantid climbed onto the box! Once I had taken the photograph I moved the box towards a flower stem and it climbed back onto the flowers, seemingly unperturbed by the photo shoot.

Black circular marks can be seen on the back of the head behind the eyes and just below where the antennae sprout from the top of the head. The mantid in this photo is looking down and so its wedge-shaped face is hidden from view.

With the camera I currently have it is particularly challenging to photograph these creature – firstly, because they are so tiny, and secondly because they are so well camouflaged. Difficulties with the light (too bright or too dark) and breezes rocking the plants added to complexities.

I use a bridge camera and its macro functionality is not really good enough, and standing back and zooming-in is also unsatisfactory. I fiddled with editing photos quite a bit to try to make it possible for these exquisite creatures to be better discerned from the background.

I even resorted to isolating the creatures from the rest of the photograph to try to make them clearer to see. Interestingly, whenever I get close to them, they tuck their antennae back and flatten them down, which they also seem to do when in ambush hunting mode. Once I move away they are confident enough to erect their antennae again, while they are obviously watching me.

One of the spiny flower mantid nymphs in typical hunting posture – facing down with antennae folded back. It can clearly be seen in this photo how the very long forelegs are folded double. These legs extend incredibly far and incredibly quickly when the mantid reaches out suddenly to grab prey. The spiny abdomen is folded up over the back, concealing the eye spot that develops on the nymph at each stage (instar) of development after the exoskeleton is shed.

So far I have been lucky enough only once to see one of the mantid nymphs shedding its exoskeleton. By the time I saw it, the process was nearly completed. In the photo above, the nymph is hanging down upside down with the exoskeleton somewhat crumpled adhering to the underside of a leaf. The abdomen is elongated and what looks like the beginnings of an eyespot can be seen on the upper-side of the abdomen. I assume that the wings are starting to develop although I cannot see them at this stage. The two black spots behind the eyes are visible as the head is tucked down towards the forelegs.

Watching solitary bees and other insects visiting the basil flowers is somewhat nerve-wracking with the mantids in residence. As they get bigger the mantids are tackling larger prey, but in this photo the relatively robust carpenter bee was ignored by the mantis that can be seen facing away from the bee on the other side of the flower stem and further up from where the bee is hovering.

At one stage I did see a very small mantid eating a largish ant, but mostly they ignore ants that visit the flowers around them. But on one occasion we watched a mantid actively avoiding a specific (rather small) ant and even jumping onto another flower stem to get away from it.

The mantids are very good at climbing – extending their forelegs to help them move along at a surprising speed. Late one afternoon I was aware of a katydid in the basil bush but on a different stem and some distance away from the closest mantid. Suddenly the mantid started moving fast, I got distracted but then saw it had jumped onto the same stem as the katydid and suddenly there was a struggle. At first I was not sure who had captured whom, and then it became apparent that the struggling katydid was the victim.

This was the best photo I managed to get of the mantid clutching and eating the unfortunate katydid, which was still struggling and kicking its hind legs as the mantid proceeded to make an incision and commence sucking out its bodily juices while the katydid was still alive.

I was surprised at how actively the mantid hunted its prey as I have read that mostly they sit in one place ambush hunting by grabbing anything that passes or lands nearby .

Early one evening I came across one of the mantids eating a fly it had caught, but the light was so low that the photos I took are not really worth sharing.

As can be seen in the photo above the mantids cohabit with common dotted fruit chafer beetles that visit the basil bush, even in close proximity.  By the way, we cohabit with chafer beetles in our garden too. They mostly seem to eat pollen and I have not noticed them causing any significant damage to any plants.

An identified bee spent a lot of time sunning itself in the early morning at the top of a basil flower spike and it was completely ignored by the spiny flower mantid, which is well camouflaged and quite hard to see on the flower stem below the bee.

The unidentified solitary bee in the above photo flitted from flower to flower, pausing to take in nectar and it was also ignored by the mantids.  In this photo a mantid can be seen towards the top right in its typical crouching hunting posture.

Although a bit pixelated, this photo of a spiny flower mantid in profile shows one of the dark patches behind the eyes. It also gives some idea of the power and length of the forelegs folded together in the famous prayer-like posture that gives the praying mantis its name – although after watching these little predators, I think preying mantis might be a more apt spelling. The abdomen is tightly curled over the back. Yesterday, I saw one of them straightening out is abdomen and wagging it almost like a tail, revealing the eye spot on the back, but it stopped when I slowly approached and reverted to curling the abdomen up again.

And to end, another photo of the mantid on the purple broom flowers, showing how well camouflaged it is. To a degree spiny flower mantids can adapt their colour to blend in with the flower or plant they spend the most time on. Some time back, our neighbour had a shrub known as a marmalade bush with orange flowers and a spiny flower mantis nymph hung out there and adapted its colour to a deep orange to blend in with the flowers.

I hope to be able to follow the further development of these intriguing little creatures, and perhaps I will be posting about them again. I have posted previously about seeing these mantids in the garden, see here and here.

---

Sources:

Picker, Mike, Griffiths, Charles & Weaving, Alan. 2019. Field Guide to Insects of South Africa. Cape Town: Struik Nature; Wikipedia. 2021. Pseudocreobotra wahlbergii. https://en.wikipedia.org/wiki/Pseudocreobotra_wahlbergi

---

Posted by Carol