Image of the Day: Prickly Legs

Froghopper insects gain traction on smooth plant leaves by piercing them with tiny spikes.

Feb 5, 2019
Carolyn Wilke
Part of the hind legs of Philaenus spumarius froghopper insects with spines
IMAGE COURTESY OF HANNS HAGEN GOETZKE

Froghoppers (Philaenus spumarius) gain traction that lets them leap from smooth leaves thanks to spikes on their legs, according to a study published yesterday (February 4) in PNAS.

Researchers studied the insects’ hopping strategy by capturing high-speed video and taking a close look at their legs. On leaves and epoxy surfaces, the froghoppers’ hind legs gripped the surfaces when the insects took off, allowing them to soar through the air. When jumping from leaves, the froghoppers’ spines left behind microscopic holes. But on hard glass, the insects could not gain traction and slipped when they jumped. 

Froghopper leaping from an ivy leaf
MOVIE COURTESY OF HANNS HAGEN GOETZKE

H.H. Goetzke et al., “Froghoppers jump from smooth plant surfaces by piercing them with sharp spines,” PNAS, doi:10.1073/pnas.1814183116, 2019.