African Wildlife & Environment Issue 82

GARDENING FOR BIODIVERSITY

fact, P. auriculata is the lazy gardener’s friend because it does best when neglected. Insects will also help with the ‘pruning’ and, while munching the plant, make good meals for birds. You will find that these eager foliage consumers stimulate the growth of your plant without ever killing it.

The more widespread of these two butterfly species, the Common Zebra Blue (previously known as the Common Blue) Leptotes pirithous, is frequently seen flitting around lawns where P. auriculata and one of its other larval host-plants, Cape Honeysuckle Tecomaria capensis , are used as border plants. It is not just a coincidence that

these are both larval host plants of this butterfly as the plants often occur together in nature, usually with some breathtaking displays of blue interspersed with orange when they are in flower at the same time. Anyone who argues that indigenous vegetation cannot provide colour is obviously not well acquainted with these plants. The larvae of the Common Zebra Blue butterfly occur in various shades of green and brown, and are often parasitised by wasps of the genus Neotypus , little black creatures scarcely 10mm long. Once an egg has been laid on the caterpillar, instead of a butterfly eventually emerging from the pupa, out comes a new, well-fed wasp! Because these butterfly larvae secrete a honey-like liquid, ants often desperately try to reach them but are deterred by the stickiness on

The larva (caterpillar) of the Common Zebra Blue on one of its host plants, Plumbago auriculata (Photograph: S Woodhall)

the outside of the flowers of P. auriculata . The larvae and wasps however appear unhindered by this sticky surface. Pure blue flowers are relatively rare in nature and, although many insects, especially butterflies, are partial to them, they are mostly pollinated by bees. In turn, these bring in a host of predators, probably the most striking of which are the tree and rock agamas.These large insect-eating lizards are positively addicted to bees! The males have blue heads, the intensity of the colour varying from one species to another. The blue can be switched on and off quite rapidly in both territorial and reproductive displays and becomes striking when the lizards sunbathe. Because of this conspicuous colouring, they are often colloquially referred to as ‘blue-headed lizards’.

Besides beetles and the larvae of a few moth species, the caterpillars of two Blues butterflies, Leptotes species, also enjoy the flowers and immature seeds. The generally brownish-grey butterflies of these two species are so similar that even the experts find it virtually impossible to tell them apart in the field. Only the males, which are quite fond of visiting mud puddles, have a blue sheen. Both sexes have small, slender tails on their hind wings. When settled, with their heads facing down and the antennae motionless and unnoticed, they move the hind wings back and forth so that the tails mimic moving antennae. If a predator grabs at what it thinks is the butterfly’s head, the only parts lost are the tails or part of a wing. The butterfly can survive without up to a third of the wing area, but not without its head!

39 | African Wildlife & Environment | Issue 82 (2022)