Bag-shelter Moth (Ochragaster lunifer)

 

For about a week I've been watching these caterpillars as they crawled up the wall after some heavy rain. (This is my next-door neighbour's condo.) First of all they were all bundled together in one big mass (didn't think of taking a photo on the first day), but the next day I found them walking up the wall in straight lines.

Why do these caterpillars go in a line? They travel in long lines of hundreds or more in search of food or a suitable place to begin the transformation into their adult form : the Bag-shelter Moth. Together they present a formidable number of irritant hairs to predators and the conga line helps prevent them getting lost.

It is also thought that they walk in line to scare off predators who might think it is a snake. How clever!

These caterpillars are grey and hairy with a brown head. They grow to a length of about 4cms. When they mature, they will descend from their tree (or wall, in this case) to pupate in a silk cocoon in ground debris, and what hatches is the Bag-shelter Moth.

I have actually found that not many birds like to eat this moth. When touched it curls up, showing a black and red body, which I presume signals that it is poisonous.

By day three the "train" had moved higher up the wall, heading for the roof, it seemed.

Note the bunch of caterpillars behind the Sansevieria close to the ground.

For another day or two they kept on "clustering" and forming trains until eventually, all that was left was a few stragglers - I presume that the rest had descended to complete their pupation.

By the way, lots of caterpillars together is called an "army". These ones are also called Processionary Caterpillars or a "train".

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What a wonderful find! - Hawk Moth Caterpillar

Hawk moth caterpillar in a pot of Arum Lilies, now stripped of their leaves - Pic taken in my daughter's garden in Ballito, KwaZulu Natal, South Africa

This is the caterpillar of the Hawk moth, (family Sphingidae), also called sphinx moth or hummingbird moth, sitting on the left-over stalk of an Arum Lily. Butterflies and moths, as innocent as they appear, have a definite sting in the tail. To enjoy their intricate colours, their delicate dips and swings across the sun-kissed garden and their evening hovering among scented blooms, we have to live with their myriad off-spring which chomp, chew and generally deface our carefully tended plants, shrubs and trees.

Silver-striped Hawk moth (pic from "Butterfly conservation")

One of the most voracious of these is the caterpillar of the Hawk Moth, which can strip a plant of all its leaves in a matter of days. The Arum lily is one of the host plants for Hippotion celerio, commonly known as the Silver-striped Hawk Moth or Grape Vine Hawk Moth. This is an exceptionally handsome, neat looking moth with a wingspan of 76 mm and longitudinal pale brown and olive-brown stripes along the body and wings. The Arum lily is one of the host plants for this moth. These moths are widespread and abundant in Africa, breeding along the North and East coast and subsequently colonising southern Europe.

Hawk moth caterpillar in a pot of Arum Lilies, now stripped of their leaves - Pic taken in my daughter's garden in Ballito, KwaZulu Natal, South Africa.

This resident moth flashes reddish-brown patches on under-wings if disturbed. The wings can sometimes have a pinkish/purplish tinge. Adult, with a wingspan of 6.5 - 9cm, can be seen flying between May and early August.

Hawk Moth caterpillars are medium to large in size, with stout bodies and five pairs of legs. Usually the hawk moth caterpillars’ bodies lack any hairs (he/she was beautifully smooth to the touch!, and most species have a ‘horn’ at the posterior end (seen in the top photograph). Many are greens and browns, and have counter-shading patterns that help to conceal them. 

Female hawk moths lay translucent greenish, flattened, smooth eggs about the size of a tomato pip. These are usually laid singly on host plants and take between 3 to 21 days to develop. Most species are capable of producing several generations each year if weather conditions suitable.

The eggs hatch out into pale green caterpillars about a centimeter long. They hide under the leaves during the day but eat ravenously and grow at an alarming rate at night. As they grow their colour darkens darkens slightly and they lie along the upper stem of the arum where they blend perfectly.

A week or so later the teeny, cute little green caterpillar will be  staunch 7 or 8 centimeters long, turn brown and descend to the base of the plant where once again it will blend perfectly with its surroundings. Here it may spend the day in hiding, creeping up during the night to continue its depredations.

Next morning - Hawk moth caterpillar resting on the edge of the plant pot

The damage to the arum lilies was the loss of their leaves which admittedly hindered their growth but they recover. To save your Arums, visit them regularly and check for eaten leaves and along the stems, where you will find the culprits.

Before you go on the rampage, consider the results of your actions.

So now it's up to you. You may decide to pick off and destroy both the eggs and the caterpillars, but bear the results of this action in mind: birds will find less food in your garden and may leave to find food elsewhere, night blooming flowers will not be pollinated and bats will be deprived of a protein packed 'snack on the wing'.

Although appearing delicate, the eggs are surprisingly strong and difficult to crush.

This Pic from Kumbulu Nursery

Hairy wonders

As I was watering the garden this morning, I discovered a whole clump of caterpillars at the base of my Acacia karroo tree. These are the larvae of the Lappet Moth and I am lucky enough to have them hatch in my garden every October.

Their appearance also coincides with the return in mid-October of the Red-chested Cuckoo (Cuculus solitarius – Piet-my-Vrou) as they make out a large part of this Cuckoo’s diet.

Eutricha capensis, the Cape lappet moth, is a species of moth in the family Lasiocampidae primarily found in South Africa. During the larval stage, cape lappets feed on a wide variety of African plants and can often be found aggregating in gardens. The caterpillars are brightly coloured and conspicuously hairy, while the bulky adult moths are mostly brown and much less striking in appearance.

I also found another clump at the base of one of the White Karee's (Rhus viminalis) and I think they have chosen their spot well, for I doubt that the Red-chested Cuckoo will go onto the ground in my garden.

If you look close enough, you will see some water droplets on them. Luckily I saw them just in time before wetting them completely with the hosepipe! Be careful of touching these deceptively soft-looking beauties, the hairs stick to whatever they come into contact with and and can cause an irritating, itchy rash.

The adult moths are large and stocky, with an average wingspan of about 70 mm (2.8 in). Both hind wings and fore wings are reddish brown. The fore wings are flecked with yellow and bear three wavy white stripes. Females are typically paler in colour and larger than males.

I will be keeping a close eye on them over the next few days and hopefully I can capture the adults emerging.

 A typical example of one of the Lappet moths

Image from iSpot

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