Butterfly and Moth Information

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Phylum, Arthropoda; Class, Insecta; Order, Lepidoptera

Identifying Features

Appearance (Morphology)

  • Larvae are worm-like with both thoracic and abdominal legs
  • Adults with three distinct body parts: head, thorax, abdomen
  • Four wings covered with scales producing color patterns
  • Adult butterfly antennae are usually threadlike with a knob at the tip
  • Adult moth antennae can be feather-like, threadlike, or bristlelike

Adult Males and Females
Adult females are often larger than males. Male moths usually have very elaborate antennae. Coloration may be different between the sexes.

Immatures (different stages)
Lepidoptera are holometabolous, therefore they have three distinct morphological stages; larva, pupa and adult. After hatching from the egg, larvae go through a series of molts as they grow. During each molt, the old skin is cast off and a new, larger one is produced. Larval life is divided into instars, separated by molts. Larvae may be covered with hairs or protuberances. All of the larval body is soft except for the head and the claws. Three pair of short, jointed legs with a single claw at the tip are located on the three thoracic segments immediately behind the head. Three to five pairs of fleshy protuberances (prolegs) ending in a series of hooks called crockets are located posteriorly and ventrally on the abdomen and aid the larva's clinging and climbing abilities on plants.

Natural History

Most larvae of butterflies and moths eat plants. Many species are very selective about what they will eat and may feed on only one species of plant in their lifetime. Adults usually feed on the nectar of flowers, but some do not feed at all. Some larvae feed on fabric or stored grains.

Lepidoptera larvae are usually found on their food plant, but may be well hidden. They can often be found by looking for damaged leaves. Frass may be visible around the base of the plant or under a tree. Pre-pupal larvae often wander off of the food plant in search of a good place to pupate.

Many birds and some insects eat lepidopteran larvae. Bats, birds, and spiders eat the adults. Some flies and wasps are parasites on lepidopteran species.

Interesting Behaviors
Both larval and adult butterflies and moths are often highly colored. Sometimes the colors are bright and are intended to warn away potential predators. Often, this indicates that they taste bad to a predator. Other times the bright colors are meant to attract mates. Some are colored to look very much like a food plant in order to help the insect hide. Eggs of lepidoptera often have very elaborate shells, and may be either brightly colored or cryptic. The egg shell or chorion, are usually very hard to prevent predators from eating them.

Impact on the Ecosystem

The adults of butterflies and moths are well known for their beauty. They provide food for many other animals. Some species are active pollinators.

Larvae of lepidoptera can be harmful when they eat crops, and when their numbers get to be very large, as happens with the Gypsy moth. In general, however, the larvae of butterflies and moths do very little harm, and, are important in maintaining controlled plant growth.

Collecting Live Insects

Where to find
Butterflies and moths can be difficult to find, but looking for known food plants makes the task easier. Different swallowtail caterpillars eat parsley, dill, citrus leaves and sometimes carrot greens. If milkweed grows in your area, monarch caterpillars will be on the plants in the spring or summer. Locate many large moth caterpillars like the tomato sphinx caterpillar by the frass below the plant they are eating. Carefully look above the piles of frass for damaged leaves and the caterpillar. Many caterpillars feed on large trees and locating them is next to impossible unless there is an infestation. Consult local gardeners, scientists and other resource people to find good places to find caterpillars. Painted lady caterpillars and artificial food can be purchased from: Berkshire Biological, Carolina Biological Supply Company (other species of butterflies and moths available), Connecticut Valley Biological (swallowtail species available), Delta Education, Insect Lore Products, Nasco Science, Science Kit and Boreal Laboratories.

How to collect
Before removing the larva from the plant, make sure you have access to plenty of fresh food plant for it to eat. Using scissors or pruning sheers, cut off the branch or stem that the caterpillar is on. Some caterpillars are easy to gently pull off the stem, but most hang on with their prolegs and are difficult to impossible to remove without injuring them.

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Center for Insect Science Education Outreach The University of Arizona
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