Turning Ants into Fools- The Ingenious Lacewing

Douglas Mills

Green Lacewings, Neuroptera: Chrysopidae, have a unique way of protecting their eggs from insect predators like ants. Unlike other insects, they do not lay their eggs directly on a plant surface.

When a female lacewing has found a safe place to lay her eggs, she produces a drop of silk from her abdomen, pulling it out such that it solidifies and acts as a stalk, on which her egg will stand (BBC, 2005). The female lacewing repeats this up to thirty times a day, with each egg standing on it’s own stalk. She has the capacity to produce 300 eggs, equivalent to two times her own weight (Berry, 1998).

Standing mid-air, her eggs are now safe. Despite being mere millimeters from potential insect predators that walk ignorantly, they remain unknown thanks to the fine silk thread on which they stand.

Interestingly, Brown lacewings glue their eggs to the top of hairs of maize leaves. Scientists see this as an ‘intermediary evolutionary step’ between the more common depositing of eggs on plant surfaces, and the behaviour of the Green Lacewing (Duelli, 1985).

 

Reference:

P. Duelli, 1985. A ‘missing link’ in the evolution of the egg pedicel in lacewings? Experientia, 42(6):624

Ralph E. Berry. 1998 Insects and Mites of Economic Importance in the Northwest. 2nd Ed.  221p.

“The Lacewing” BBC’s Life in the Undergrowth documentary series. Globalzoo YouTube Channel, 26 January 2010. URL:

http://www.youtube.com/watch?v=0zECnVZyYDI (accessed on 05 April 2013)