Wood helps solve wasp riddle

Press, 30 December 1988, Page 29

Wood helps solve wasp riddle

PA Dunedin Blocks of firewood have helped Otago Museum’s curator of sciences, Mr Tony Harris, solve a riddle which has puzzled him since 1975. The riddle was how a “giant” brightly-coloured, parasitic wasp was finding its way into Dunedin. The wasp, known as megarhyssa nortoni nortoni, is coloured black, brown, red and yellow, and is one of the largest ichneumonid wasp species. A wasp brought to Mr Harris for identification Istst month was 12.5 cm

long, including an B.2cm ovipositor (egg-laying tube). The parasitic wasp is not harmful to human beings, preferring pine trees to people. In an article published in the “Otago Daily Times” recently, Mr Harris asked anyone with further sightings to call him.

Sixteen people brought wasps to the museum, and in doing so they solved the puzzle of how the wasp, originally from North America, was coming into Dunedin. All 16 brought blocks of pinus radiata to their homes for use .as fire-

wood. It seems both wood wasps and the giant parasitic wasps were developing inside the firewood, which came from either Taieri Mouth or Waitati. “On warm sunny days the parasites would hatch out of the wood and fly around the section,” Mr Harris said. In some cases they would hatch out in woodboxes and startle people by suddenly flying inside houses. “Some people are frightened of them, but they don’t harm humans," he said.