Southern White-barred Charaxes

EASY GARDEN BUTTERFLIES

Southern White-barred CharaxesCharaxes brutus natalensis

The White-barred Charaxes or White-barred Emperor is one of the Nymphalidae (Brush-footed Butterflies), subfamily Charaxinae (Emperors, Queens etc.). ‘Southern’ because this is the southern subspecies of an Africa-wide species. This male is perching atop a Strelitzia nicolai leaf, watching his territory for intruders.

The Charaxes are the swashbuckling ‘big flashies’ of the butterfly world. They aren’t typical garden butterflies because they tend not to visit flowers, preferring to inhabit the forest canopy. There they fly high, engaging in aerial battles with other big butterflies and even birds. They are usually regarded as being wild species that are scarce and difficult to observe.

Having said that though, there are a few species whose caterpillar host plants are often found in gardens. One of them is this one. Its wingspan is from 60 to 90mm making it one of the biggest garden butterflies.

Although it’s not a regular nectar feeder an adult White-barred Charaxes has been known to visit large flowers like Strelitzia. It is not difficult to observe them in a garden setting. The kind of fruit bait people use to attract fruit-eating birds works on Charaxes. And if you have a dog, it will leave pieces of Charaxes bait all over your lawn… it will also come to your outside dining area to help itself to some wine!

Distribution

The Southern White-barred Charaxes is found across the eastern side of South Africa, traditionally only found in the moist subtropical areas. The species is found over a wide area of sub-Saharan Africa.

Recently its host plants have been planted well outside their historic range, often in attempts to replace exotic street trees with indigenous, although not necessarily locally indigenous, species. In addition it has shifted to using the foliage of a widely distributed exotic tree.

As a result, this butterfly is now found in Cape Town, Bloemfontein, and Johannesburg!

And it is spreading…

Egg

Charaxes lay their eggs singly, on the surface of leaves. They are large and almost spherical with flattened tops carrying fine ribs radiating from the centre . When freshly laid they are pale yellow to green, developing a dark ring around the upper surface if fertile.

White-barred Charaxes eggs are 1.6mm high and 1.7mm in diameter. The egg stage lasts about nine days, then the young larva eats its way out and usually consumes the empty shell.

Caterpillar

Charaxes caterpillars have characteristic ‘head shields’ in the shape of a hand with the ‘fingers’ (known as ‘horns’) pointing back towards their body. They have roughly cylindrical bodies with no hair or spines, and a forked or ‘bifid’ tail. They usually have a characteristic marking on the middle of the back. The skin is finely rough with many tiny warts.

Young caterpillars’ head shields are usually dark and large in proportion to their bodies. As they grow the colour changes to match the (usually green) colour of the body. They eat leaves from the edges and spin a silken pad that they rest on between feeding sessions.

Fully grown White-barred Charaxes larvae have blue-tinged head horns and a yellowish circular mark on the back.

They grow from 4.5mm to about 52mm over four moults. The process usually takes about about five weeks but it can take a lot longer in winter when they enter diapause.

Pupa/Chrysalis

The White-barred Charaxes pupa is green and has a squared-off abdomen. Like all Nymphalidae pupae it is attached to its substrate by its tail. It is usually formed on the same silken pad the caterpillar used as a resting perch during its development.

The pupa is 25-28mm long and the adult usually emerges after 2-3 weeks. This may take longer in unfavourable conditions. Before emergence the pupal shell becomes transparent and the adult inside becomes visible.

Host plants

Southern White-barred Charaxes caterpillars eat the leaves of trees like Natal Mahogany Trichilia emetica, Cape Ash Ekebergia capensis, and Honeysuckle-tree Turraea floribunda. They also use the exotic invader Syringa Melia azedarach. This is almost everywhere in SA at present. We’re not advocating you plant this to attract them, but it goes to show that it’s an ill wind that blows nobody any good!

How to attract them

Gardeners wishing to attract this butterfly would need to commit to planting a tree that can grow rather large. Having said that they are attractive trees with the ability to withstand a certain amount of cold and drought conditions.

Nectar plants are not the best way to attract this butterfly. Deliberate baiting with fermenting fruit is the secret to success.