Treehoppers put obsolete genetics to fashionable use – Roger Highfield – New Scientist

August 1 2011, 4:29pm

(Image: Alex Wild)

The designs of Philip Treacy, creator of the "fascinator" worn by Princess Beatrice at this year's royal wedding, pale in comparison with the efforts of tiny insects called treehoppers.

The insects sport bizarre "helmets" on their backs that are cunningly shaped to mimic aggressive ants, as in the case of this species from Ecuador. Other members of the 3000-plus species look like thorns, caterpillar droppings, seeds or leaves.

The helmet was thought to be an outgrowth of the treehopper's thorax - the middle part of its body - but this year, a French team reported that the helmet is in fact an entirely new type of appendage, jointed at the base like a leg, antenna or wing.

When insects first evolved 350 million years ago, they were able to grow wings from all three of their thoracic segments. However, 100 million years later, a body plan (Hox) gene brought the ability to suppress wing formation in the first thoracic segment by blocking the genes involved. Read more