Camouflage is commonly used to help animals blend with their background. Most species have a fixed pattern or colour adapted to their usual habitat. For the camouflage to be effective they need to locate on some part of their habitat with the same background colour as themselves. Certain species have a limited ability to change colour to match their background.
Many other species use shape and texture, an addition to colour, as a means to blend in with their background. Some of them are very effective in mimicking other parts of their habitat. Birders will be well aware of Scops Owl tightening its feathers and erecting its ‘ears' to look like a piece of bark or a broken stump.
The tawny frogmouth, overseas, does the same thing. There are many insects that look like bark or a piece of grass. Many species boldly mimic other forms of life to try and foil identification or to give the impression that they are dangerous to predators. Once observers have become aware of various forms of camouflage a whole new world of interest will be opened up to them.
The two main reasons for camouflage are to evade predation or for effective ambush of their prey. Examples are endless and I would like to focus on a couple of species that are relatively easy to find at this time of year.
If one examines flowers closely you will note a variety of insect life. Apart from the butterflies, bees, wasps and other flying insects that visit the flowers there are resident ants, mites and aphids. There are predators that lie in wait on the flowers for these visitors. If you look closely you are very likely to find little ‘crab spiders' that closely match the colour of the flower. They wait to one side with legs ready to pounce on the visitors.
Much larger but often harder to spot, especially when they are in their nymphal form, are the ‘Flower Mantids'. The creatures we call ‘preying mantis' are all mantids that belong to the order MANTODEA. They are all typically identified by a pair of spined forelegs that fold under the head ‘as though in prayer'.
With these forelegs they catch their prey. They have horizontal jaws with which to chew their food. The order is divided into eight different families. There are around 1800 species described with adaptations to every conceivable type of habitat. In our region 185 species have been recorded in five families.
The ‘bark', ‘leaf ' and ‘flower' mantids all belong to the Family Hymenopodidae. There are two species of flower mantis that you are likely to find on suitable flowers and they are extremely hard to spot even at close range.
The Eyed-Flower Mantid
- Pseudocreobotra wahlbergi
- that is identified by the ‘eye' on the wings when these develop, is quite common in our north-eastern area. It is mottled pink, green, brown and white and the nymphs look very like the flower parts on which they sit. They are quite territorial and will stay on the same flowers until the flowers die or until weather or predators remove them.
They are most interesting to watch each day when you visit that part of the garden and provide a challenging game of ‘hide and seek'. The ‘Flower Mantid' - Harpagomantis tricolor - a creature with similar colouring but lacking the ‘eye' on the developed wings, is wide spread over most of South Africa except the very dry western area. It has similar habits and occurs in our area.
‘THORN INSECTS’ !
The ‘Bugs', which are identified by having ‘piercing and sucking' mouthparts, belong to the large Order HEMIPTERA - which is divided into two Sub-orders - HOMOPTERA and HETEROPTERA. These sub-orders are divided into over 90 different families with around 67,500 species worldwide. Many species are potential crop ‘pests' because of their sucking habits and also as vectors for viruses, bacteria and fungi that cause plant diseases.
Most are totally harmless to agriculture. Included in this order of insects are species familiar to most people - bed bugs, stink bugs, tip or twig wilters, assassin bugs, water beetles, water scorpions, pond skaters, water boatmen, shield bugs, spittle bugs, aphids, scale insects, leaf hoppers, tree hoppers and cicadas.
Just as an indication of the surprises hidden in a study of any of these families is the fact that we have 140 known species of cicadas (or Christmas beetles) in our region - with very little information known about many of them. The Family - Cicadidae - all suck plant sap and remain underground as nymphs for many years before emerging to moult as adults and mate.
The family - Membracidae - the ‘Treehoppers' - have similar feeding habits but do not live below ground. The adults of some species of treehopper are shaped to resemble thorns as a means of camouflage. There are at least four genera occurring in the north-eastern areas of South Africa and they are interesting little creatures to observe. A common one in our area belongs to the Genus - Oxyrachis - and it can be found on, mainly, trees with bipinnate leaves such as ‘Albizia', ‘Acacia' and ‘Dichrostachys'.
The easiest way to find them is to look for ant activity on tree branches. As with aphids and other members of the sub-order, the ants ‘milk' the ‘treehoppers' for a sweet excretion passed out after sucking the plant sap. The treehoppers lay their eggs in slits in the tree bark and the nymphs hatch out to live in small groups on the bark. They lack the ‘horns' of the adults and try and hide when alarmed. Even when sub-adult with ‘blunt horns' they try and hide in sheltered spots.
Adults and young are protected and tended gently by a variety of ants that stroke them with their feelers to ‘milk' them. It is uncertain what specific role they play in the ‘greater scheme' of nature but they are sure to have some function and do not present any threat to plantlife.
They are just one of the fascinating aspects of the ‘micro-world' available to those that are disillusioned with commercialisation and politics of the ‘Big 5'. Take a slow ‘mini safari' round your garden and look closely at each plant (maybe with the help of a magnifying glass) to discover a whole new world of interesting creatures. That have just as much right to live as those ‘economically advantaged' elephants. Take great care with what and how you apply insecticides which could end up killing the birds and other animals around you.