KNYSNA NEWS - Dave Edge and Hanna du Toit began to look for the famous Brenton blue butterfly (niobe*) in the last week of October, when they sometimes emerge, but not this year.
Into November they were looking every few days whenever the weather was suitable (fine and warm with no wind) but such days were few and far between.
By the middle of the month not one had been seen and they were beginning to fear the worst.
Maybe all the caterpillars had been killed by the intense heat of the fire – the botanists were saying that the humus layer had burnt completely in some places and this could have destroyed the seeds in the seed bank.
As far as is known, the caterpillars are at least 150mm below the ground – but was this enough?
Also, there was a possibility that the rootstocks of the Indigofera erecta (the host plant of the butterfly) could have burnt, but fortunately by late August the first resprouting had been seen, indicating that many rootstocks had survived.
So the absence of niobe was puzzling and concerning although hardly any other butterflies were seen.
They searched on 19 November in perfect weather conditions but without success.
Conditions were again good on the 24th and they did their usual search, for the first time seeing the water bronze butterfly Cacyreus fracta, looking at first glance like a niobe.
They were almost done when just before 13:00 a smallish butterfly was seen behaving like a fracta but settling with its wings closed (fracta normally has its wings half open to catch the sun).
Dave crawled closer to get a better look and when he drew level he could see the underside – undoubtedly niobe with its black spots on a grey background, and no tails!
C. fracta has an intricate pattern on its underside and a short tail on each hindwing.
The niobe flew away before it could be photographed, but later, at 13.20, Hanna saw it again about 30m away, crawling on a low Indigofera erecta plant and she was able to get a photo.
When she called Dave over he was able to confirm it was a niobe female, although quite badly worn, with pieces broken away from its hindwings – typical damage on butterflies indicating a predator attack (probably a bird).
Searching the plant it had originally been on he found two freshly laid eggs (pale blue in colour, they go white within a day), and on another nearby erecta, two more eggs.
Photo: André Coetzer.
They were naturally very excited by the find and searched for more adults, but without success.
The next day the weather was again fine and they set out with high hopes of seeing more niobe but were disappointed when none could be found, despite searching the whole reserve.
Since a single swallow does not make a summer, the butterfly team (also including Christa le Roux of Brenton) will continue their search in hope of finding some more niobe adults or their eggs.
* The scientific name of the Brenton blue “niobe” comes from Niobe, one of the most tragic figures in Greek mythology. Her seven sons and seven daughters were killed by the gods Apollo and Artemis, and she was turned to stone. From this rock it is said that a ceaseless stream of her tears has flowed ever since. Let us hope that we do not have to shed tears over our “niobe” and that she is made of sterner stuff.
* The full report into the research being conducted after the June fires is contained in the November newsletter of the Brenton Blue Trust and it, together with more detailed information about niobe, can be found on www.brentonbluetrust.co.za.
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