Lacewing Silk

September 28, 2009

GREEN LACEWING consumption of moth eggs, small caterpillars, spider mites, aphids and other pests promotes sustainable biological pest control in farms, gardens, greenhouses, zoos, malls, conservatories and other landscapes. Sustainable cotton farmers around the world have long utilized green lacewings for biocontrol, but few ever had an inkling that both cotton AND lacewings could be fiber crops. Indeed, biocontrol companies like Rincon-Vitova Insectaries, which has a green lacewing logo, may one day be garbed in garments woven from organic cotton and green lacewing silk.

Not that green lacewing silk is likely to make a major fashion splash anytime soon or displace traditional mulberry-reared silkworm cocoon threads. Rather, adding another insect silk to the textile design palette is just another milestone marker from several decades of studying the chemistry, genetics, biology, physics, acoustics, ecology, etc. underlying biocontrol by green lacewings. The latest technical details from Australia’s Commonwealth Scientific Industrial and Research Organisation (CSIRO) on the superior textile properties of green lacewing egg-stalk silks is just one more brick in the ecological edifice.

Ecologically, besides finding shelter from the elements and locating nourishment, the real world for an insect is also a constant struggle to avoid being prey to natural enemies. Even pest natural enemies like green lacewings are preyed upon by their own set of natural enemies (e.g. spiders, bats, parasitic wasps, ants). Lacewings adapt by eavesdropping on bat echolocation signals (a form of radar used for navigation and prey detection) and flying evasive flight patterns. Green lacewings trapped in silken orb spider webs have their own almost ritualistic behaviors for chewing themselves free, and tiny wing hairs are designed to smoothly slide free from sticky spider webs.

Thin tough silken egg stalks that are strong yet flexible loft green lacewing eggs safely out of the reach of marauding ants. For extra protection, the high-protein silk egg stalks are also coated with oily ant repellent chemicals. Interestingly, the egg stalk silks are very different from green lacewing cocoon silks. Textile buffs are intrigued, as egg stalk silks rapidly solidify after being secreted as liquid droplets that are extruded into thin strong fibers swaying like palm tree trunks topped with lacewing eggs.

From an engineering standpoint, these green lacewing egg stalk silk properties suggest the possibility of new industries and biological silk factories. In a future decade, green lacewing silk may be woven along with silkworm silk and cotton into apparel and furnishings. An unexpected dividend from years of research related to green lacewings and biocontrol.