Timber scientist Erhard Heinemann in front of the Cranach altar
Posted on 03/13/2005 5:05:15 PM PST by wagglebee
A sixteenth-century altar in one of Germany's most historically important cathedrals has been saved from woodworm not by the application of chemicals, but by a swarm of wasps.
The Cranach altar in the Erfurt Cathedral was being destroyed by the wood-eating insects, but officials delayed taking action because they feared that chemical treatments might damage its 11 painted panels.
Instead they adopted a pioneering technique which may now be emulated in historic buildings across Europe: releasing 3,000 parasitic wasps, which feed on woodworm larvae.
The towering wooden altar, riddled with holes, and the large painting above it which also showed signs of damage were enveloped in a blue plastic tent.
The air in it was heated to 68F to ensure that the wasps - whose natural habitat is the Mediterranean region - did not fly off and for five weeks, the wasps, just one tenth of an inch long, were allowed to prey on the destructive larvae until scientists estimated that none would be left.
Andreas Gold, the head of the town's episcopal building authority, said that the method had proved cheaper than chemicals and less risky to the altar, or to Lucas Cranach the Elder's 16th-century painting, The Mystic Marriage of St Catherine.
"The wasp project cost us £2,000. Asphyxiating the woodworm with nitrogen would have cost £3,500," he said.
Visitors to the church were assured that the wasps posed no risk. Peter Weidemann, the Erfurt diocesan spokesman, said: "They are totally safe for people. This type of wasp is in any case very small - as they have to be, or they could never get into the holes to sort out the woodworm."
The wasps, Lariophagus distinguendus, sting the woodworm larvae before the females deposit their eggs inside them. When the eggs hatch, the wasp larvae feed on the body of the host.
Mr Weidemann said: "The Cranach altar has become the platform for an important experiment, which if proved to be successful will open many doors in the future. This is a real alternative to chemical extermination."
Erhard Heinemann, a timber scientist, said that he had the idea after a similar experiment involving paper. "I successfully bred similar wasps once, to save some books from bookworm," he said.
Scientists are checking that all the woodworm were eradicated, by examining infected logs placed near the altar when the wasps were released.
GGG Ping
Timber scientist Erhard Heinemann in front of the Cranach altar
My, those are tiny wasps.
Ich bin Timber-liner.
Looks like your usefulness extends beyond the crevo threads :-)
At least you would think they would post a picture of the little critters in their article. Would have been nice to know what they look like.
Best FReegards,
D2
Gotta send a link to the bug dude.
Isn't John Edwards a parisitic WASP?
#10. Pretty Neat Looking Little Critter. Thanks for the Pic.!!!!:-)
Best FReegards,
D2
:-)
Lucas Cranach der Ältere
Verlobung der Heiligen Katharina
Tafelbild im Erfurter Dom
Please FREEPMAIL me if you want on, off, or alter the "Gods, Graves, Glyphs" PING list --
Archaeology/Anthropology/Ancient Cultures/Artifacts/Antiquities, etc.
The GGG Digest -- Gods, Graves, Glyphs (alpha order)
Please remove my previous post - NOT the picture intended. Guess I didn't "read the rules."
Thank you for this post, wagglebee.
Wonderful concept.
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