Cornicles are tubes that project from the abdomen of an aphid. There are usualy a single pair of cornicles with one on each side of the abdomen. The cornicles are used to emit pheromones or defensive secretions. It is often incorrectly believed that honeydew is secreted from the cornicles.

What is the function of Cornicles in aphids?

Aphids fed various concentrations of sucrose in water produce varying amounts of cornicle lipid, depending upon the sugar concentration in the diet. The primary function of cornicle droplet emission in aphids appears to be that of removal of excess lipid metabolized from a diet high in carbohydrates.

What insects have cornicles?

Cornicles are two small appendages at the end of the abdomen that are only found in aphids. Aphids are very small insects about the size of a pinhead.