Leaf of the day: Galls and more Galls

I have spent a large part of today sorting out my nature table which is now overrun with twigs and bits of leaves, many seed pods, cones and dried leaves. The pods from the milkweeds have burst open and errant fairy seeds waft around the room with every breath of air. It’s truly a jumble, but in amongst it all was this small leaf I had picked up one day, with two wasp galls firmly attached to the underneath. It’s such a pleasing object. Not quite a exquisite as the potter wasp’s beautifully made pot which I still have here, and not as comical as the gouty galls I drew some time ago (both here). But the simple arrangement of two perfect little spheres on this leaf make this wasp a bit of an artist.

Galls and other insect built homes are fascinating but these are particularly creative. They are the designs of the Gall Wasps, Family Cynipidae, who, although wasps, are tiny, often no bigger than a fruit fly. The galls are formed by abnormal growth of the plant cells stimulated by chemical secretions produced by the wasps either feeding or laying eggs. The plant tissue grows up around the eggs to protect the larvae, but why they are such extraordinary shapes and colours is a mystery. I can see that some imitate twigs but something red and spotted is not really very well camouflaged.
There are saucer galls, beaked twig galls, dunce cap galls, red cone galls, and spined Turk’s cap galls and everywhere I looked I found more. But this site, BugGuide. net here will give you wonderful identification photos by a variety of photographers. Here are some of the examples.

Starburst Gall

Spined Turbaned Gall

Disk Gall

Saucer gall

Horned gall

Hairstalk Gall

Beaked Twig Gall

Spiny Leaf Gall

More photos and a informative article from Hawk Conservancy Trust .org here

Robin’s Pincushion Gall

Ramshorn Gall

There is an excellent and informative poster “Wasp Galls on Californian Oaks” by Ron Russo here . His comment rings true, “the behaviours and structures that have evolved for the successful survival of Gall Wasps are among the most intriguing stories of nature” It’s a great poster.. Hmm.. decisions? .. If I just move the Nine Inch Nails poster over a bit, there will be room for the Oak Galls.. :).

But they are fabulous aren’t they? I realise now I have a couple more which I thought were tiny fungi growing on a twig. I may draw those tomorrow.

Oak Galls

Leaf of the Day: A Potter Wasp’s Pot

If you were of a whimsical turn of mind you could be forgiven for imagining that this delicate tiny mud pot, carefully cradled in the apex of the these leaves, was the work of some fairie hand. Having celebrated the work of the gall wasp a couple of days ago, I am now delighted to bring to your attention the clever potter wasp.

Here is a super picture of a potting wasp doing an excellent job ….(I can think of many potters I know who would give their eye teeth to have 4 arms… 2 never seem quite enough somehow).
This of course is to be the nest for the wasp grub. (if you are a caterpillar lover you do not want to know how they are fed)
The image is from a great website about Australian Insects, “Brisbane Spiders and Insects” here . There is step by step guide to the techniques of the potter wasp too but most humans, without the benefit of antennae and 6 legs, will find it tricky .

I seem to be having a bit of a run on lovely natural structures at the moment, but when you take the time to look at the natural world, it is no wonder that designers, architects and engineers turn again and again to nature for inspiration and an elegant solution to a practical problem.


Potter Wasp Pot

Leaf of the Day: Gouty Galls and Leonardo’s Ink

A couple of days ago I was talking to Pedro about the lovely bluey black Iron Gall Ink which I had with me that day. It is made by Blots “carefully blended to a medieval recipe” which I am sure still involves oak galls and I am very interested in these odd but curiously attractive little objects.
Iron Gall ink was the most important ink in written history. Leonardo’s notes, Bach’s compositions, Rembrandt and Van Gogh’s drawings, the USA Constitution and the Dead Sea Scrolls were all recorded in iron gall ink. The particular property which made it invaluable was its permanence, the earlier carbon-based ink could be easily rubbed off parchments, but iron gall ink reacts with collagen in the parchment and so etches itself into the surface.
This was very useful for important documents which needed to be tamper proof but it fell out of use when paper became a more available. It has a nasty habit of destroying paper and some old manuscripts have to be “read” through the holes left where the ink has eaten its way though the paper completely.
To make the ink, oak galls are crushed to obtain gallotannic acid. This is then mixed with water and iron sulphate and then when gum arabic is added as a suspension agent, you have iron gall ink.

Here are two beautiful Leonardo botanical studies.

Later that day Pedro returned with some wonderful galls he had seen on the live oak here. I had drawn some oak galls last year in Spain which I found growing on the cork oaks in Andalucia. The cork oak galls are round like little sputniks or old fashioned bombs and I think are mealy oak galls, but this one from the live oak is a stem gall and rejoices in the evocative name “gouty” gall

Galls have names as odd as their looks. There are, jumping, wool sower, gouty, horned, and rolly poly galls and and more, and their formation is as intriguing as their names. They are the “work” of single tiny dedicated wasps whose lava produce plant growth-regulating chemicals which react with the plant tissue to stimulate tissue growth of the plant. The resulting galls can be all shapes and sizes, and provide food and shelter for the developing young grub.
The whole subject of galls is fascinating and there is another complicated relationship with other insects who attach themselves to the wasp lava and benefit from the shelter of the gall..Maybe that is why the one I drew today has other holes. I have some more research to do and some more drawings to make this time in iron gall ink of course. I just managed this one today which is like little waving alien.

I had another half day at Leu today and did couple more colour studies along with chatting to an ornithologist about the woodpeckers and watching the lizards and listening to the cardinals and more nice time wasting. I have not had time to photograph the sketches but that is my job for tomorrow.


Oak Galls, Gouty and Mealy