More than one type of silk per silk worm
CSIRO scientists have just revealed their findings on the rare silk that lacewings use to make their egg stalks.
“We have identified and sequenced the genes for the egg stalk silk of adult females of a common Australian green lacewing, Mallada signata,” CSIRO Entomology’s Tara Sutherland said. “We found that the lacewing egg stalk silk contains two fibrous proteins which are folded up like panels in a concertina door.
“The silk in the egg stalk is produced as a liquid and dries in few seconds in air. It is very strong with a high lateral stiffness—nearly three times that of silkworm silk—and remarkable elasticity.” A female lacewing produces the silk as a drop of liquid which she then draws out. The thread hardens in a few seconds and the female then lays an egg on its tip, protecting the egg against predators.
Dr Sutherland said this is another fascinating insight into the world of biological silks. Scientists have long sought to produce artificial insect silks. Understanding this lacewing silk brings them closer to achieving their goal.
According to Dr Sutherland, silk production is a multi-step process that involves making the proteins and then fabricating these into the physical structure of silk.
While the silk proteins from bee and ant silks are easier to produce chemically, it is the much simpler way lacewings fabricate their silk that has caught the scientists’ interest.
