Stigmella sophorae facts for kids

Stigmella sophorae is a tiny moth that lives in New Zealand. It belongs to a family of moths called Nepticulidae, which are known for being some of the smallest moths in the world. This special moth is sometimes called the kōwhai moth because its young, called larvae, love to eat the leaves of kōwhai trees.

What the Kōwhai Moth Looks Like

This moth is very small! Its front wings are only about 3 millimeters long. That's about the size of a small ant.

When You Can See Them

Adult kōwhai moths have been seen flying in February. They are also active from August to December. This moth usually has one group of babies, called a generation, each year.

Life Cycle of the Kōwhai Moth

The young moths, known as larvae, are very interesting. They are about 2 to 3 millimeters long and are pale green.

What Larvae Eat

Kōwhai moth larvae eat the leaves of two types of kōwhai trees. These trees are called Sophora tetraptera and Sophora microphylla. The larvae are also known as leaf miners. This means they live inside the leaves and eat the soft parts.

How They Mine Leaves

When a larva starts eating, it makes squiggly paths inside the leaf. These paths are called "mines." Eventually, the larva eats almost all the space inside the leaf. Usually, only one larva lives in each small part of a leaf. However, larvae might live in nearby leaf sections too.

The waste left behind by the larvae is called frass. It starts out green but quickly turns gray. Young mines look a lighter green than the rest of the leaf. Larvae have been seen from April to August.

The Cocoon

When the larva is ready to change into an adult moth, it builds a cocoon. This cocoon is light brown and is usually attached to the stem of the kōwhai plant.