Eastern Tailed-Blue Butterfly: ID Secrets!

The Eastern tailed-blue butterfly (Cupido comyntas) is a small, charming butterfly found throughout eastern North America. Known for its iridescent blue color and delicate “tails” on its hindwings, it’s a delightful sight in gardens and fields. This butterfly favors legumes like clover and beans as host plants for its caterpillars, and it plays a vital role in pollination. Spotting one is easy with its small size and distinctive markings!

Have you ever been captivated by a tiny flash of blue flitting through your garden? Chances are, you’ve encountered the delightful Eastern tailed-blue butterfly! These little beauties are common throughout eastern North America, but their small size often means they go unnoticed. Identifying them can be tricky, and understanding their life cycle is key to attracting them to your yard.

Don’t worry! With a few simple tips and tricks, you’ll become an Eastern tailed-blue expert in no time. We’ll explore their unique characteristics, preferred habitats, and how you can create a butterfly haven right in your backyard. Get ready to discover the enchanting world of these tiny blue jewels!

Table of Contents

What is the Eastern Tailed-Blue Butterfly?

The Eastern tailed-blue (Cupido comyntas) is a member of the Lycaenidae family, also known as the gossamer-winged butterflies. These butterflies are generally small and often brightly colored. The Eastern tailed-blue is a particularly widespread and common species, making it a favorite among butterfly enthusiasts. The species was named by American entomologist John Abbot in 1797.

Key Characteristics:

Size: Small, with a wingspan typically ranging from 7/8 to 1 1/8 inches (2.2 – 2.9 cm).
Color: Males are generally bright blue on the upper side of their wings, while females are blue only at the base, with the outer portions brown or gray. Both sexes have gray or light brown undersides.
Tails: Distinctive, thread-like “tails” on their hindwings, which are often mistaken for antennae.
Spots: A row of black spots bordered with orange on the hindwing underside near the tails.

Habitat and Range:

The Eastern tailed-blue is found throughout eastern North America, from southern Canada to Florida and west to the Great Plains. They thrive in a variety of open habitats, including:

Fields
Gardens
Roadsides
Open woodlands

They are highly adaptable and can be found in both rural and urban environments. The Eastern tailed-blue can also be found in Central America.

Life Cycle:

Like all butterflies, the Eastern tailed-blue undergoes complete metamorphosis, with four distinct stages:

Egg: Tiny, greenish-white eggs are laid singly on the flower buds or young leaves of host plants.
Larva (Caterpillar): The caterpillar is small, green, and slug-like. It feeds on the leaves, flowers, and seedpods of its host plant.
Pupa (Chrysalis): The pupa is typically green or brown and blends in with its surroundings. It is attached to the host plant by a silk girdle.
Adult: The adult butterfly emerges from the pupa, ready to reproduce and continue the cycle.

Step-by-Step Guide to Identifying the Eastern Tailed-Blue Butterfly

Identifying butterflies can sometimes feel like a puzzle, but with a few key observations, you can confidently identify the Eastern tailed-blue. Here’s a step-by-step guide:

Step 1: Observe the Size

The Eastern tailed-blue is a small butterfly. If the butterfly you’re observing is significantly larger than an inch, it’s likely not an Eastern tailed-blue.

Step 2: Check the Wing Color

Observe the upper side of the wings. If it’s a male, it will be mostly blue. If it’s a female, it will be blue near the body, with the rest of the wing being brown or gray. However, the most reliable way to ID is to inspect the underside.

Step 3: Look for the “Tails”

This is the most distinctive feature. Look for the delicate, thread-like tails on the hindwings. These tails are fragile and can sometimes be missing, but they are usually present.

Step 4: Examine the Underside Markings

The underside of the wings is gray or light brown with a row of black spots bordered with orange near the tails. These spots are a key identifying feature.

Step 5: Consider the Location and Habitat

Are you in eastern North America? Is the butterfly in a field, garden, or roadside? The Eastern tailed-blue is common in these areas. If you’re in a different region or habitat, it might be a different species.

Step 6: Use a Field Guide or App

If you’re still unsure, consult a butterfly field guide or a butterfly identification app on your smartphone. These resources can provide additional information and images to help you confirm your identification. Some popular options include the Audubon Butterfly Field Guide and apps like iNaturalist.

Attracting Eastern Tailed-Blue Butterflies to Your Garden

Want to see more of these beautiful butterflies in your yard? Here’s how to create a butterfly-friendly habitat:

1. Plant Host Plants

Host plants are essential for caterpillars. Eastern tailed-blues rely on legumes as host plants. Some excellent choices include:

Clover (Trifolium species)
Alfalfa (Medicago sativa)
Beans (Phaseolus species)
Peas (Pisum sativum)
Vetch (Vicia species)

Planting a variety of these legumes will provide a buffet for hungry caterpillars.

2. Provide Nectar Sources

Adult butterflies need nectar for energy. Plant a variety of nectar-rich flowers that bloom throughout the growing season. Some favorites include:

Asters (Aster species)
Black-eyed Susans (Rudbeckia hirta)
Butterfly Bush (Buddleja davidii)
Coneflowers (Echinacea species)
Lantana (Lantana species)

3. Create a Butterfly Puddling Area

Butterflies need water and minerals. Create a “puddling” area by filling a shallow dish with sand or gravel and keeping it moist. You can also add a pinch of sea salt or wood ashes to provide essential minerals.

4. Avoid Pesticides

Pesticides can harm or kill butterflies and caterpillars. Avoid using pesticides in your garden, or choose organic options that are less harmful. Consider using natural pest control methods like introducing beneficial insects or hand-picking pests off plants.

5. Provide Shelter

Butterflies need shelter from wind and predators. Plant shrubs and trees to provide resting places and protection. A brush pile in a corner of your yard can also provide shelter for butterflies and other wildlife.

6. Let the Sun Shine

Butterflies are cold-blooded and need sunlight to warm up. Make sure your garden has plenty of sunny spots where butterflies can bask.

Eastern Tailed-Blue Butterfly vs. Similar Species

Several other small blue butterflies can be confused with the Eastern tailed-blue. Here’s a comparison to help you tell them apart:

Species	Key Characteristics	Range
*Eastern Tailed-Blue (Cupido comyntas)*	Small size, tails on hindwings, row of black spots bordered with orange on underside.	Eastern North America
*Spring Azure (Celastrina ladon)*	Small size, blue upperwings, underside pale blue or white with faint markings, lacks tails.	North America
*Summer Azure (Celastrina neglecta)*	Similar to Spring Azure, but emerges later in the season.	Eastern North America
*Ceraunus Blue (Hemiargus ceraunus)*	Small size, blue upperwings, underside with more prominent dark markings, has tails.	Southeastern United States
*Western Tailed-Blue (Everes amyntula)*	Very similar to Eastern Tailed-Blue, but found in western North America.	Western North America

Important Note: The Western Tailed-Blue is nearly identical to the Eastern Tailed-Blue. Unless you are certain of your location being in the West, it’s safer to assume it’s an Eastern Tailed-Blue if you’re in the East!

The Ecological Importance of Eastern Tailed-Blue Butterflies

Eastern tailed-blue butterflies play a vital role in the ecosystem:

Pollination

As they flit from flower to flower in search of nectar, they transfer pollen, helping to pollinate plants. While they are not as efficient pollinators as bees, they still contribute to the reproduction of many plant species.

Food Source

Eastern tailed-blue caterpillars and butterflies serve as a food source for birds, spiders, and other insects. They are an important part of the food web.

Indicator Species

The presence or absence of Eastern tailed-blue butterflies can indicate the health of an ecosystem. Their sensitivity to environmental changes makes them valuable indicator species. A decline in their population could signal habitat loss, pollution, or other environmental problems.

Fun Facts About Eastern Tailed-Blue Butterflies

The “tails” on their hindwings are thought to mimic antennae, confusing predators and causing them to attack the wrong end of the butterfly.
Eastern tailed-blue caterpillars have a symbiotic relationship with ants. The caterpillars secrete a sugary substance that ants feed on, and in return, the ants protect the caterpillars from predators.
They are multivoltine, meaning they have multiple broods per year. This allows them to quickly repopulate areas after disturbances.
The Eastern Tailed-Blue is not endangered, but habitat loss and pesticide use can threaten local populations. Supporting butterfly conservation efforts and creating butterfly-friendly habitats can help ensure their survival.

Conservation Efforts for Butterflies

While the Eastern tailed-blue is not currently endangered, many other butterfly species are facing serious threats. Here are some ways you can help protect butterflies:

Support butterfly conservation organizations: Organizations like the Xerces Society work to protect butterflies and their habitats.
Create butterfly-friendly habitats: Plant host plants and nectar sources in your garden, and avoid using pesticides.
Advocate for conservation policies: Support policies that protect butterfly habitats and reduce pesticide use.
Educate others: Share your knowledge about butterflies with friends, family, and community members.
Citizen Science: Participate in citizen science projects to help monitor butterfly populations and track their movements. The North American Butterfly Association (NABA) is a great place to start.

Resources for Further Learning

Want to learn more about butterflies? Here are some helpful resources:

Butterfly Field Guides: Peterson Field Guide to Eastern Butterflies, Kaufman Field Guide to Butterflies of North America
Websites:
Books:
- “Butterflies of North America” by Jim P. Brock and Kenn Kaufman
- “National Audubon Society Field Guide to North American Butterflies”

FAQ About Eastern Tailed-Blue Butterflies

What do Eastern Tailed-Blue caterpillars eat?

Eastern Tailed-Blue caterpillars primarily eat legumes, such as clover, alfalfa, beans, peas, and vetch. They feed on the leaves, flowers, and seedpods of these plants.

How can I tell the difference between a male and female Eastern Tailed-Blue butterfly?

Male Eastern Tailed-Blue butterflies are generally bright blue on the upper side of their wings. Females are blue only at the base of their wings, with the outer portions being brown or gray.

Are Eastern Tailed-Blue butterflies migratory?

No, Eastern Tailed-Blue butterflies are not migratory. They typically stay within a relatively small area throughout their lives.

How long do Eastern Tailed-Blue butterflies live?

The lifespan of an Eastern Tailed-Blue butterfly is relatively short, typically lasting only a few weeks as an adult.

What is the purpose of the “tails” on their wings?

The “tails” on their hindwings are thought to mimic antennae, confusing predators and causing them to attack the wrong end of the butterfly. This gives the butterfly a better chance of escaping.

Are Eastern Tailed-Blue butterflies endangered?

No, Eastern Tailed-Blue butterflies are not currently endangered. However, habitat loss and pesticide use can threaten local populations.

What is the best way to attract Eastern Tailed-Blue butterflies to my garden?

To attract Eastern Tailed-Blue butterflies, plant host plants like clover and beans, provide nectar sources like asters and coneflowers, create a butterfly puddling area, avoid pesticides, and provide shelter.

Conclusion

The Eastern tailed-blue butterfly, though small, is a captivating creature that adds beauty and ecological value to our world. By learning to identify these butterflies, creating butterfly-friendly habitats, and supporting conservation efforts, we can help ensure their survival and enjoy their enchanting presence for generations to come. So, step outside, observe these tiny jewels, and become a champion for butterfly conservation!