Butterflies and Moths

Diversity and distribution

The insect class Lepidoptera, which includes moths and butterflies, is an incredibly diverse group with over 160,000 known species. These insects are characterized by their scaled wings and a unique proboscis used for feeding on nectar or other liquid food sources. Lepidoptera is divided into numerous families and genera, with some of the most well-known families being Papilionidae (swallowtails), Nymphalidae (brush-footed butterflies), and Sphingidae (hawkmoths), among others.

Lepidoptera insects can be found in a wide range of countries across the globe, inhabiting diverse environments such as forests, grasslands, and urban areas. They can be found on every continent except Antarctica.

Life cycles of Lepidoptera

The life cycle of Lepidoptera insects consists of four stages: egg, larva (caterpillar), pupa (chrysalis or cocoon), and adult. The duration of each stage varies among species.

Female Lepidoptera lay their eggs on or near their preferred food source, depending on the species. Upon hatching, the caterpillars begin to feed and undergo several molts as they grow. Once they reach their final larval stage, caterpillars form a chrysalis or cocoon and undergo metamorphosis to become an adult butterfly or moth.

Lepidoptera and fly fishing

While adult Lepidoptera insects are not typically considered a primary food source for fish, their caterpillar stage is most relevant to fly fishing, particularly for trout and other insectivorous fish. Some well-known Lepidoptera larvae that are targeted by fly fishers include:

• Inchworm: these small, green caterpillars can often be found dangling from trees near the water and can be an easy target for fish when they fall into the water. You can use inchworm patterns, which are typically tied with a slim, segmented body, to imitate these insects.
• Caterpillar: various caterpillar species can be found near aquatic environments, and when they fall into the water, they can become a food source for fish. 
• Caddisfly larvae: although caddisflies belong to the insect order Trichoptera, their larval stage closely resembles Lepidoptera caterpillars. You can use caddisfly larva patterns to imitate these insects.