Wednesday 22 August 2012

Flowering Currant and Vapourer Moth and Magpie Moth caterpillars

Flowering Currant

I will always remember my visits to my grand parents’ house in Cardiff because their back garden had two very big Flowering Currant (Ribes sanguineum) bushes.  It wasn’t the pretty dark-pink flowers or even the strong resinous and fruity smell the leaves gave off if brushed against, though these were very enjoyable to see and smell that captured my attention, it was something that I could discover hiding in the foliage. It was the amazing caterpillars I could more or less guarantee finding on these bushes.

I would take a jam jar to capture some and take them home to keep so I could watch them as they changed first into pupae and later into adults. I was fascinated by all of this at an early age and still am! I used to learn about the species of insects I found by looking them up in good books on the subject.  I used to have the Observer’s Book of Larger British Moths.

Magpie Moth

The Magpie Moth (Abraxas grossulariata) is a beautiful species of moth with white wings dotted with black and yellow and a yellow body also marked with black. 

Magpie Moth

 It is in the Geometer moth family, or Geometridae,  and all species in this group have very cute “looper” or “inchworm” caterpillars that, as the name suggests, don’t crawl but make a loop out of their bodies as the pull the rear end up to catch up with the head section. They can stretch out in front of themselves as if they are testing or measuring what is ahead. Some types are camouflaged to look just like twigs and are almost impossible to see when they are completely still. Many types of caterpillar in this large family can also spin a long thread of silk if they are dislodged from where they are feeding. They can defy gravity by climbing back up these threads after all danger has gone.

The caterpillars of the Magpie Moth are a similar colour scheme to the adult moths and are mainly black and white like the Magpie bird the species is named after. They change into shiny black pupae striped with yellow. They are anchored loosely in a very flimsy cocoon that is almost non-existent and is made in dead leaves or tucked away somewhere on the bush the caterpillar fed on or near it.

The Magpie Moth was once a very common species though for some reason its numbers have declined drastically in recent years.  . This is somewhat surprising because it has a very wide range of food plants and besides the Flowering Currant can also feed on Gooseberry, Plum, Spindle, Hawthorn, Privet and many other shrubs and small trees. Maybe this decline is due to Climate Change because the caterpillars are the stage of this moth that has to survive the winter months.

Vapourer Moth

The second species of moth caterpillar I could often find on the Flowering Currant bushes was the Vapourer Moth (Orgyia antigua). This is a really weird insect because the females don’t look anything like a moth but more like a fat woodlouse. They have no wings apart from tiny stubs and cannot eat either. Basically they are a living bag of eggs and after mating with a male they lay their eggs and then die.
The male Vapourer Moths get a much better deal because they have normal wings which are coloured a rusty brown and they fly by day and night.

 Female Vapourer Moth

The caterpillars are really pretty creatures with dark greyish bodies covered with hairs and tufts of hair in yellow and blackish. The ones that will become female moths are much bigger than those that are the males. They pupate in a proper silk cocoon that they spin up somewhere on the bush or tree they are on. The female moths very often stay put after emerging and actually lay their eggs all over their old cocoons. They overwinter in this stage and hatch out in spring.

Vapourer Moth caterpillar

The Vapourer Moth is a very widely distributed species and can sometimes become a pest because its larvae can feed on a very wide range of plants, shrubs and trees besides the Flowering Currant.
Both species of moth gave me a lot of joy when I was a youngster and, as well as teaching me about the sometime very strange things that happen in the natural world, I learned how to look after them and see to their needs. Later that summer I was rewarded by seeing the adults hatch out.