Stick insects: Egg-laying techniques reveal new evolutionary map

Known for exceptional mimicry, stick insects have evolved a range of egg-laying techniques to maximize egg survival while maintaining their disguise—including dropping eggs to the ground, skewering them on leaves, and even enlisting ants for egg dispersal. Scientists have now combined knowledge on these varied techniques with DNA analysis to create the best map of stick-insect evolution to date. Contrary to previous evolutionary theories based on anatomical similarities, the new analysis finds the first stick insects flicked or dropped their eggs while hiding in the foliage. It also finds that geographically isolated populations of stick insects are more likely to be related than those with similar features. The research, published in a special issue on stick insects in Frontiers in Ecology and Evolution, takes us one step closer to understanding these enigmatic creatures.