Butterflies and Moths

Butterflies and moths are the adult flying stage of the order of insects known as Lepidoptera. The name Lepidoptera comes from the Greek words for scale and wing. They are terrestrial (live on land) and are found in nearly all types of habitats and in all regions of the world except Antarctica. Butterflies are some of the most attractive insects, while moths form a more diverse group. Alberta is home to over 170 different kinds of butterflies and over 2000 different species of moths. 

The Rotary Butterfly and Hummingbird gardens have been developed to attract butterflies and other valuable pollinating insects and birds.

In the early 2000s Professor Dr. Dave Larson surveyed the butterflies in the Stoney Creek Valley. Shortly thereafter he began to study moths. He estimates there are 100-120 species of moths in the valley and a fifth as many butterfly species. Here are a few of the butterflies that have been observed in the Stoney Creek Valley over the last number of years:

Butterflies – Morning Cloak, Common Sulphur, CA Tiger Swallowtail, Milbert’s Tortoise  Shell and Monarch.

Moths – Alfalfa Looper, Dingy Cutworm, Sigmold Prominent, Lappet Moth and Black Witch

The Monarch Butterfly and Black Witch Moth do not reproduce here but have been observed in recent years. Local lepidopterist Dave Larson wishes to track their local appearance.

There are five families of butterflies found In Alberta:

Skippers – distinguished by antennae which are thickened and hooked near the tip, they have strong thick bodies, large eyes and subdued colouring.

Swallowtails – distinguished by large wings commonly yellow and black in colour with a tail on the rear edge of each hind wing. 

Whites, Sulphurs and Marbles – medium-sized with mainly white or yellow wings.

Gossamer wings – small butterflies divided into three sub-families: coopers which are mainly orange and black, hairstreaks which are usually brown or grey and blues which are primarily bright blue.

Brushfoots – the largest family of butterflies in Alberta. They have tiny brush-like front legs.

The migrating ranges of individual butterfly species vary widely with some species such as the Painted Lady and the Monarch migrating over long distances. These migrations take place over several generations and no one individual makes the whole trip. Monarch migration can be as far as 3800 km while the Painted Lady can extend as far as 5000 km.

Lepidoptera are flying insects and have two pairs of scaly wings. Since they have four wings, they have eight wing surfaces and often the upper and lower wing surfaces have different patterns. The patterns and colours on the wings of butterflies and moths are made up of tiny, coloured scales. The scales are so small that without a microscope, they look like coloured dust. The scales are also very fragile and will brush off the wing if rubbed.

Butterflies and moths have six legs and three main body parts: head, thorax, and abdomen. On many, the front two legs are reduced, and the insect walks on 4 legs. Their heads have two large compound eyes, two antennae and a long sucking tube called a proboscis which is often coiled when not in use. The proboscis is the butterfly’s mouthpart and it is used to suck up liquids such as nectar and water. They are only able to sip on liquids with their proboscis and cannot pierce or break the skin, so there is no such thing as a stinging or biting moth or butterfly.

How can I tell a butterfly from a moth?

• Butterflies have thin wire-like clubbed or hooked antennae, moths have feathered antennae
• Butterflies pupate in a chrysalis, most moths spin a cocoon
• Butterfly caterpillars are generally spiny (not hairy), moth caterpillars are generally hairy (not spiny)
• Butterflies are active during the day while most moths are active at night. An exception is the Hummingbird Hawk-moth which is a day flyer
• Butterflies primarily rest with wings folded back and moths rest with wings in a horizontal position

Lepidoptera have four stages of development: 

• egg
• larva (caterpillar)
• pupa (cocoon or chrysalis)
• adult. 

Some species will remain dormant as eggs or pupa for long periods, in order to survive winters. The longest period of their life cycle is spent in the larval stage. Most adult Lepidoptera live for only one or two weeks.

Due to their short life span, most of an adult butterfly’s focus is on reproduction. When you see an adult butterfly, it is likely in search of a mate (males) or searching for a place to lay eggs (female) or finding food to fuel its searches.

Butterflies tend to lay their eggs on or near the food plant of their caterpillar and each species has its own food preference. In the caterpillar stage, there are four or more molts of the entire outer skin with the final shedding exposing the pupa or chrysalis. While in the pupa, the caterpillar body undergoes metamorphosis and is transformed into that of an adult butterfly. When metamorphosis is complete, the pupal skin splits and the butterfly emerges, unfolds, dries its wings and then takes flight.

Both butterfly and moth caterpillars have chewing mouthparts. Caterpillars eat vegetation, mostly leaves and sometimes flowers and flower buds, while adult butterflies feed primarily on nectar from flowers. They may also feed on pollen, tree sap, rotting fruit, dung, decaying flesh, and dissolved minerals in wet sand or dirt. 

The caterpillar stage is the growth stage of the life cycle and the amount a caterpillar can eat will determine the size of the adult and how many eggs can be laid. Some species are considered pests because in their larval (caterpillar) stage they can cause damage to domestic crops and trees. Some moth caterpillars will even chew holes in clothes, blankets and carpets made from natural fibres like wool, felt, silk and fur.

Do they cause problems? What role do they play in our ecosystem?

Moth caterpillars can cause significant agricultural damage. One example is the Diamondback moth larvae which feed on all plants in the Brassicaceae family. In Alberta, canola and mustard are its primary targets as well as vegetable crops such as broccoli, cabbage, cauliflower, and kale. Other examples of damaging moth larvae in Alberta include the forest tent caterpillar, the Cutworm moth, the Alfalfa Looper and the Bertha Armyworm.

A butterfly pest well known to gardeners is the Cabbage Butterfly. Its green caterpillars feed on cabbage and other related plants. Cabbage butterflies have two or three broods per year with the last brood hibernating over winter as the chrysalis and emerging in early spring.

While they do cause damage, moths and butterflies also benefit plants by pollinating flowers while feeding on nectar.  Pollen collects on their feet while feeding and although they may not carry as much pollen as bees, they can transport it over greater distances and thus they aid in seed production of both wild and food crops. To attract them to your garden you need to plant host plants as well as nectar plants. Host plants are those where butterflies lay their eggs and they provide food for caterpillars. Certain species of caterpillars will only eat certain plants so that is where butterflies will lay their eggs.

Do they have predators and how do they protect themselves?

Butterflies experience predation in all life stages. Their main predators include birds, ants, spiders, and wasps.  By virtue of being present on plants, caterpillars are exposed to predation from birds, wasps, and hornets.  In addition, eggs and larvae are threatened by parasitoids - organisms that live in close association with their host, at the host’s expense, resulting in the death of the host. One such example is the Parasitic wasp which lays its eggs in Lepidoptera eggs or larvae.  The wasp’s parasitoid larvae then devour their hosts, usually pupating inside or outside the desiccated husk.

Butterflies use a variety of means to protect themselves from predators such as chemical defences or camouflage. Chemical defences are mostly based on chemicals of plant origin.  Plants have evolved such that they contain toxic substances as protection against herbivores, and butterflies in turn have evolved mechanisms to sequester these plant toxins and use them instead in their own defence. These defence mechanisms are then advertised by way of bright colours in unpalatable butterflies. One common example is the Monarch, which is poisonous to birds and other predators in the caterpillar and adult phases. The Monarch's colouration is often mimicked by other butterflies, such as the Viceroy which looks like a smaller version of the Monarch. Another defence is camouflage, where butterflies at rest can resemble dead leaves or bark and caterpillars can appear like sticks or branches. Other caterpillars resemble bird droppings or have large hairs that provide protection. Their colour helps them to blend in with host plants.

Another threat to butterflies and moths is habitat destruction, from agriculture, forestry, mining and other industrial activities and urbanization. Other threats of varying severity are pesticide use, pollution, artificial lighting, climate change and the spread of non-native species. Despite the damage they can cause, the decline of moth and butterfly populations should be of concern as they are an important food source for many other species. 

Enchanted Learning, All about Butterflies

Wildlife Insight, Moth Anatomy

Alberta Government, Major Crop Insect Pests

Wikipedia: Butterfly

Identification, Butterflies and Moths of Alberta

Insects of Alberta, Butterflies, Moths

Edmonton & Area Land Trust, Happy National Moth Week!

Butterfly Conservation, Butterflies

• A Guide to Familiar American Insects, Herbert S. Zim and Clarence Cottam, 1956, Golden Press

• The Complete Illustrated Book of Garden Magic, Roy E. Biles, 1969, J.G. Ferguson Publishing Company

• University of Alberta Insect Pests of the Prairies, Hugh Philip and Ernest Mengersen, 1989, U of A Printing Services

• Butterflies of Alberta, John Acorn, 1993, Lone Pine Publishing

• Nature Scape Alberta, Myrna Pearman & Ted Pike, 2001, Red Deer River Naturalists and Federation of Alberta Naturalists 

Photo sources

Darcy and Lea Polny are graduates of the Alberta University of Arts. They worked as graphic designers for many years as Groundwater Communications while raising their family and now spend time creating fine art. Darcy has written and published two children’s books and won seven international fine art competitions for his watercolours. Lea paints in acrylics and volunteers her design and marketing abilities to support the Bailey Theatre.

Shirley Rostad - Rotary Club of Camrose member

Kim Boyco - Rotary Club of Camrose member