The elusive Wolkberg Zulu butterfly

For the last few years, members of the Lepidopterists’ Society of Africa have been on a mission: they’ve been searching for a new colony of one small, endangered and very elusive insect: the Wolkberg Zulu butterfly (Alaena margaritacea). Just recently, their efforts paid off. Naturalist Andre Coetzer describes what’s it’s like to be on the hunt for the butterfly version of a needle in a haystack...

Looking for a new colony of this butterfly really is like looking for a needle in a haystack … except you only have a three-week window at the peak of the rainy season! If you’re successful, you might make a headline or two. If not, there is always next year ... because giving up is not an option!

The butterfly is called the Wolkberg Zulu (Alaena margaritacea), and although it was first described way back in 1929, it’s only ever been known to occur in one locality: a small town in northern South Africa. Collectors and researchers alike have scoured the surrounding area for many years looking for another colony, without any luck.

2014 02 24 Wolkberg Zulu Butterfly Distribution Map
The Wolkberg Zulu butterfly is only ever been known to occur in one locality: a small town in northern South Africa.
Searching for the Wolkberg Zulu is a tedious, challenging task involving long treks over rocky terrain.

About 26mm in size (roughly the size of a US quarter), Alaena margaritacea is not an easy tracking target. Unlike most other butterflies, it’s got a habit of settling very frequently and for very long periods … which makes searching for it a tedious, challenging task involving long treks over rocky terrain while combing and scrutinising the grass and undergrowth. And there’s another problem: the Wolkberg Zulu has an extremely short flight period (the ‘winged’ adult part of its life cycle) – just three weeks in December and early January that also happen to fall right in the middle of the rainy season. All of this easily explains why no one has found another colony of this elusive and endangered butterfly in the last 80 years. Until now...

The discovery of a new colony of Wolkberg Zulu butterflies bodes well for this threatened species.

Early in January, a botanist who’d been studying wild flowers in the area stumbled upon something that was small, colourful and dainty … and it wasn’t a wild flower. It was Alaena margaritacea. A few days later, members of the Lepidopterists’ Society headed out to confirm the sighting. Although the weather wasn’t playing along, a lone male was found lying frozen on a leaf, and the following day, a number of the butterflies were spotted fluttering amongst the grasses.

The discovery of the colony is important. While not much is known about the species or its life cycle, we do know that the Wolkberg Zulu is a small butterfly with big problems. In its original locality just outside the town of Haenertsburg, the butterfly is threatened by the proximity to plantations and habitat destruction (the butterfly's larvae probably feed on lichens, which are very sensitive to changes in the environment). The new colony is situated in a much bigger area of unspoilt wilderness, but even here the butterfly is threatened by nearby mining activity and expanding human settlements.

“Looking for a new colony of this butterfly really is like looking for a needle in a haystack … except you only have a three-week window at the peak of the rainy season!”

2014 02 24 Wolkberg Zulu Butterfly Scenic
Expanding human settlements pose the biggest threat to this rare butterfly species.

With the future of the Wolkberg Zulu and other threatened butterflies at risk, the Lepidopterists’ Society of Africa has launched an intensive research programme to learn as much as possible about Africa's critically endangered butterfly species so that well-planned conservation efforts can be put in place in the future (and at the current rate of habitat destruction, that day is probably not too far off).

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2014 02 24 Wolkberg Zulu Butterfly