Frass

Frass is the term given to the droppings/faeces of insect larvae. Frass is commonly associated with wood boring species as often this the evidence of insect activity within a piece of wood.

Frass is also a term used by people who rear butterflies and moths to describe the solid excretion of caterpillars.

A photograph of a Squash vine borer (Melittia cucurbitae) larvae. The plant stem has been cut open to show the larvae and the frass.
Photograph by Pollinator licensed under Creative Commons.

Related terms

• Caterpillar
• Wood borer

Related groups of terms

• General biology
• Insect life cycles

See other words beginning with F