Is it or is it not extinct? That is the question when it comes to the Brenton blue butterfly.
And while it has been a year since the iconic butterfly was seen, chief custodian Dr Dave Edge has not given up hope that they might have survived extinction.
“This is their normal period of emergence and we’ve had some windless, sunny weather so the conditions are ideal for it to make an appearance.
“I’ve been going out to check each day and there’s nothing so far, but we’re still hopeful,” he said on Tuesday.
Concerns about the Brenton blue’s survival stem from the June 2017 fires which ravaged Knysna and tore through the 1.6ha Brenton Blue Butterfly Reserve in Brenton-on-Sea, the last stronghold of the little blue insect.
The species briefly emerged in November of that year but did not appear during the following February, as per its usual secondary emergence cycle.
In June 2018, when The Herald visited Knysna to record how the town had resurrected itself a year after the fires, Edge said the butterfly’s absence was likely linked to the simultaneous disappearance of a particular ant.
When the Brenton blue is still in its caterpillar stage, the ant species Camponotus baynei drags it below ground to the base of the Indigofera erecta plant where it feeds on nectar excreted from the honey gland on the caterpillar’s back.
At the same time the caterpillar feeds on the nutritious root of the erecta.
In good times, in the ground beneath the erecta, the Brenton blue transforms into a pupa and then an adult butterfly, which crawls to the surface.
Emerging, it dries its wings, flutters off, mates within 24 hours and dies two to three weeks later.
The nocturnal baynei nests in decaying logs – but the problem is the ones on the Brenton blue reserve were all burnt.
One of the rescue strategies for the Brenton blue therefore was to capture some baynei from elsewhere on the Brenton peninsula and to relocate them to the reserve.
But Edge said on Tuesday that no other populations of the ant had yet been found.
“We’re still trying to find and capture another population of baynei and at the same time every day we’re checking the reserve for the ant and the Brenton blue itself.
“When the butterfly emerged last November it was at the end of the month and it may be that the fire caused the emergence cycle to shift slightly so we’re going to keep looking.”
The Brenton blue was discovered in 1858 in Knysna but was not seen again until 1977, when a small population was found at Nature’s Valley.
This population died out in the 1980s but in 1991 Ernest Pringle, of Bedford, discovered another colony at Brenton-onSea on the outskirts of Knysna.
A housing development was planned for the site, but this was prevented after a highly publicised campaign to save the species from extinction.
The land was subsequently procured by the national government, and the Brenton Blue Butterfly Nature Reserve was proclaimed in July 2003.