Purple Hairstreak Butterfly: Identification, Life Cycle, and Behavior

Discover the fascinating world of the Purple Hairstreak Butterfly. Learn about its identification, life cycle, and unique behavior.

Get ready to encounter intriguing insights that will deepen your understanding of this remarkable creature.

Purple Hairstreak butterfly

What is the Classification of Purple Hairstreak Butterfly?

The Purple Hairstreak Butterfly, scientifically named Favonius quercus, falls under the broad categorization of butterflies in the family Lycaenidae.

Also known as the hairstreaks, Blues, or coppers. This family is the second largest among butterfly families, hosting more than 6,000 species worldwide.

Favonius quercus is split into numerous species based on slight differences in appearance and habitats. Despite these variations, all species share common, observable characteristics that make identification possible.

The Purple Hairstreak, being native to the United Kingdom and parts of Europe, is notably distinct from its North American counterparts.

Here’s a breakdown of its classification:

  • Kingdom: Animalia (animals)
  • Phylum: Arthropoda (invertebrates with an exoskeleton)
  • Class: Insecta (insects)
  • Order: Lepidoptera (moths and butterflies)
  • Family: Lycaenidae (hairstreaks, coppers, Blues)
  • Genus: Favonius (hairstreak butterflies)
  • Species: quercus (the specific species that is the Purple Hairstreak Butterfly)

Exploring this classification reveals that a Purple Hairstreak Butterfly is an animal, specifically a type of invertebrate known as an arthropod.

It is an insect that belongs to the order of moths and butterflies, and within that, to the family of Hairstreaks, Blues, and Coppers.

Its genus is Favonius, which comprises various Hairstreak butterflies, and then finally, we have the specific species that is the Purple Hairstreak, Favonius quercus.

What is the Distribution of Purple Hairstreak Butterfly?

The Purple Hairstreak Butterfly, scientifically known as Quercusia quercus, enjoys a wide distribution range; from Western Europe through to Eastern Asia.

Specifically, in Britain and Ireland, they’re widespread but are not so apparent due to their high-flying nature.

Here’s a glimpse of their global distribution:

  • Europe: Found in the majority of Europe, absent only in the far North.
  • Asia: From western Asia, extending to Japan in the East.

Revealing a preference for deciduous forests and woodlands, these butterflies particularly appreciate areas with a high concentration of oak trees, their primary host.

This explains their common presence in oak woodland habitats across Ireland and the British Isles.

The species adapts well to warmer climates, so they’re typically spotted in Southeast Asia.

However, their distribution range reduces significantly in colder regions of Mongolia and Siberia, as they tend not to thrive in those cooler territories.

What are the Main Characteristics of the Purple Hairstreak Butterfly?

The Purple Hairstreak Butterfly possesses some striking physical traits which set it apart from its counterparts.

This butterfly species is typically small in size, with the wingspan ranging from 1.2 to 1.6 inches (30 to 40 millimeters).

Their fascinating coloration is undoubtedly their most unique characteristic.

  • Colour: The defining aspect of these butterflies is their distinctive purple-blue iridescent sheen on the upper side of their wings. This dazzling color is most prominent in males, becoming an effective means of identification. However, it’s worthwhile to note that this color isn’t always visible, as it strongly depends on the angle of light. A dark border is also present, providing a striking contrast.
  • Shape and Layout: The wings of the Purple Hairstreak Butterfly have an interesting shape and layout that further aids in identification. Their forewings are relatively smaller, giving a uniquely compact outline when their wings are held together.
  • Underwing: One unique feature tied to the Purple Hairstreak is the intricate patterning upon the underwings. These display a combination of white, black and orange, intermingled in a unique and complex pattern.
  • Eye-spots: A trait commonly recognized in this butterfly species relates to the eye-spots found on the underwings. This adaptive mechanism aids in the butterfly’s survival as it confuses potential predators.

These characteristics, from the iridescent color to the unique pattern on their underwing, make the Purple Hairstreak Butterfly an enthralling species to observe and study.

How to Identify Male and Female Purple Hairstreak Butterfly?

There is a slight difference between the male and female Purple Hairstreak butterfly that you can use for identification purposes.

Male Purple Hairstreaks possess an impressive flash of iridescent purple on the upper side of their wings.

On the other hand, the iridescent purple on the upper sides of female Purple Hairstreaks can only been seen at a certain angle, given it is limited to a small area.

  • Males: Look for a palpable iridescent purple sheen that spans across the upper side of their wings. This vibrant colour is prominent and quite striking which makes the identification of males significantly easier.
  • Females: The females display a more subdued display of colours. The iridescent purple is contained only to a restricted area near to the body of the butterfly.

To help you distinguish between the two, remember that while both share the purple streak on their upper wing, in females it’s only a strip, whereas in males it’s more prevalent.

The intricate details of these patterns are your guide to determining the sex of a Purple Hairstreak Butterfly.

What is the Mating Ritual of Purple Hairstreak Butterfly?

The mating ritual of the Purple Hairstreak butterfly is a captivating spectacle. Males usually start the courtship, flying up high into the tree canopy searching for females.

Once they find a potential partner, they begin to exude pheromones which compel the response from the female.

After the female is attracted, the couple participates in a dance-like ritual. They flutter around each other in a rhythmic, mesmerizing flight.

This process may last from several minutes to an hour. After this ballet in the air, if the female accepts the male’s advances, they eventually mate.

It’s worth noting that timing plays a crucial role in Purple Hairstreak’s mating process. As dusk falls, these butterflies find their mates, and it’s not uncommon for their mating to continue overnight.

By using these cues, you can witness the fascinating romance of the Purple Hairstreak butterflies.

What Does the Caterpillar of Purple Hairstreak Butterfly Look Like?

Caterpillars of the Purple Hairstreak Butterfly are distinct, the design is ingenious. About 16mm long or just under 3/4 inch, these larvae are a feast of colors.

Exhibiting a pattern of yellow and white on a bed of different shades of green, they blend admirably with their favorite food – the oak leaves!

The journey starts off as minute, oval-shaped eggs, nearly 1mm wide. Tiny caterpillars emerge, bearing a striking pale-yellow hue.

Observing closely, you’d notice their bodies are cylindrical, juxtaposed with segments that bear minute hairs.

As they mature, so does their mimicry. Developing a green color, they masquerade as buds, leaves or even oak twigs.

Here’s the kicker – the deception is so compelling, even a trained eye might overlook them. Their bodies bear remarkable twisted ridges, akin to oak leaf veins, boosting their deceiving appearance.

Interestingly, they possess unique tentacle-like structures called ‘scoli’, their use largely unknown. Speculations suggest they play a part in communication or defense.

Lastly, the larvae of the Purple Hairstreak have a fascinating trait. They’re active mainly at night, hidden in the safety of the oak tree in the daytime.

Undoubtedly, these caterpillars are masters of camouflage who embrace a journey of deception ultimately leading them to their beautiful transformation.

What is the Life Cycle of Purple Hairstreak Butterfly?

The life cycle of the Purple Hairstreak Butterfly, just like other butterflies, comprises of four stages, such as egg, larva (caterpillar), pupa (chrysalis), and adult butterfly.

Each of these stages presents a different survival strategy, fascinating in its unique adaptations to the woodland environment these butterflies inhabit.

Egg The female Purple Hairstreak Butterfly starts this life cycle by laying small, spherical, white eggs on young leaves or buds of specific host plants, primarily oak trees.

These tiny gems, often undetectable to an unaware eye, hatch into caterpillars within 10-14 days in warm weather.

Larva The caterpillar, or larva stage, is focused on growth. The Purple Hairstreak caterpillar has a green body with diagonal white stripes on their sides, and their head is black.

Over approximately 30 days, the caterpillar will experience rapid growth, shedding its skin, also known as ‘molting’, up to four times as it grows to approximately 1/2 inch (1.27 cm).

Pupa The caterpillar forms a chrysalis, also known as a pupa—an intricate envelope resembling dead leaf fragments, almost 9/16 of an inch (1.5 cm) in length. Inside, a remarkable transformation (metamorphosis) occurs. This phase lasts about two weeks, give or take due to weather conditions.

Adult From the chrysalis emerges a winged adult, ready to commence the cycle again, populating the treetops with a flicker of metallic purple hues.

The adult Purple Hairstreak Butterfly is truly a sight to behold, with females displaying more dramatic coloration than males. Their short adult life of 7-15 days is mostly spent feeding, mating, and laying eggs.

This cycle, unique to insects, is the Purple Hairstreak Butterfly’s strategy to ensure its genetic legacy, a beautiful life journey emblematic of its resilience and adaptability.

What Is the Average Life Expectancy of a Purple Hairstreak Butterfly?

The life span of the Purple Hairstreak Butterfly, like most butterflies, is relatively short. The adult butterfly phase lasts only around 2 weeks in summer, an ephemeral existence structured around mating and reproduction.

Their total life cycle, however, encompassing the egg, caterpillar, chrysalis, and adult stages, spans roughly a year.

It’s imperative to understand this discrepancy; when discussing ‘life expectancy’, we frequently refer to the adult phase.

Here’s a brief breakdown:

  • Egg Stage: Lasts approximately 2 weeks
  • Caterpillar Stage: Lasts around 4 weeks
  • Pupa or Chrysalis Stage: Can be up to 10 months (as they overwinter in this stage)
  • Adult Butterfly Stage: Approximately 2 weeks

The simple truth is their flighty, glistening presence is as fleeting as it is beautiful. Yet, that transience makes their part in our ecosystem even more crucial.

If we take the time to appreciate these delicate creatures, we also learn to value their fragility, and that of the natural world in general.

What Does the Diet of a Purple Hairstreak Butterfly Consist Of?

The diet of a Purple Hairstreak butterfly is both distinct and straightforward.

Adult butterflies mainly consume honeydew, a sweet liquid produced by aphids, quite unlike many other butterfly species that feed on flower nectar.

Honeydew is rich in amino acids and sugars, providing all essential nutrients needed for the butterfly’s survival and reproduction.

For ease of understanding, here’s a breakdown:

  • Main food source: Honeydew
  • Rarely consumes: Flower nectar

On the other hand, caterpillars feed exclusively on leaves of their host plants. The Purple Hairstreak larvae predominantly prefer Oak trees (both English and Turkey oaks), serving as their primary source of nutrition.

It’s fascinating to see how they follow the rhythm of nature, synchronizing their feeding with growing seasons of their specific host plant.

From emergence to becoming a pupa, the caterpillars feast on the rich, fresh foliage, ensuring they are well fed before reaching dormancy.

  • Primary caterpillar food source: Oak leaves

Understand that the dietary choices of the Purple Hairstreak butterfly influence its lifecycle and habitat preference.

This relationship between the Purple Hairstreak butterfly and its food sources is yet another testament to the delicate balance found within ecosystems.

By focusing on their diet, you now hold a bunch of vital pieces in the big puzzle of the life and behavior of the Purple Hairstreak butterfly.

Remember, it’s the small details that compile into the big picture. With every morsel of honeydew they consume or leaf they munch on, these butterflies continue to dance their harmonious ballet with nature.

Which Plants Serve as the Primary Hosts for Purple Hairstreak Butterfly?

When it comes to forming a habitat and laying their eggs, Purple Hairstreak Butterflies show a clear preference. Their primary hosts are oak trees.

Yes, you heard it right! Oak trees are at the epicenter of their existence.

Within the oak species, the Purple Hairstreak Butterfly seems to favor the Quercus robur or commonly known as the Pedunculate Oak in the UK.

Why this particular species? Well, it boasts broad crowns and lobed leaves—perfect for shielding tiny eggs and later, the hungry caterpillars!

An outlier in this respect is the Mediterranean subspecies, which tends to lay its eggs on holm oaks. The Italian and Grecian landscapes, dotted with these evergreen oaks, offer them a perfect home.

Let’s not ignore the outliers. Although not their primary choice, Purple Hairstreaks have been found to establish colonies on other types of trees.

To name a few, Apple, Pear, and Cherry trees can sometimes play host to these butterflies. But remember, these are exceptions to the rule.

To summarize, the Purple Hairstreak Butterfly primarily depends on oak trees for survival. However, adaptability is a trait that all creatures share, and this butterfly is no different.

When the need arises, it can and will make a home on other trees.

What are the Unique Mimicry Behaviors in Purple Hairstreak Butterfly?

Purple Hairstreak Butterflies are masters of deception. They are known for their incredible mimicry skills.

Mimicry is a vital survival tool for these butterflies, enabling them to avoid predators and increase their lifespan.

One of the key features of this mimicry lies in the butterfly’s wings. The upper side of the wings are striking, metallic purple, and the underside is brown with a white streak. This side mimics leaf veins to blend in with their surroundings.

Another notable aspect is their antennae positioning. The Purple Hairstreak’s long, thread-like antennae and tail can give an illusion it’s the head of the butterfly.

This confuses predators, redirecting them to the less vital part of the butterfly.

Additionally, these butterflies mimic the movement of leaves in the wind by shaking their wings rapidly. Predators mistake them for leaves, giving the butterflies a better chance of survival.

Hence, the mimicry behavior of the Purple Hairstreak Butterfly is multifold – their color pattern, the strategic structure of their body, and their peculiar movements all contribute to convincing and diverting predators.

This unique behavior has fascinated scientists and enthusiasts alike, contributing to the overall charm and allure of these splendid creatures.

In essence, the Purple Hairstreak Butterfly’s survival and success as a species can be attributed largely to its remarkable mimicry behavior – a truly remarkable adaptation.

What Are the Main Threats to Purple Hairstreak Butterfly Populations?

Habitat loss remains the biggest threat to the Purple Hairstreak Butterfly. As with many wildlife species, the destruction of their natural habitats has a devastating effect on their populations.

These habitats may be destroyed for several purposes. Specifically, issues such as urban development, deforestation, and agricultural intensification have greatly reduced their living spaces.

Climate change is another significant problem. The consistent shifts in weather patterns create an unstable environment for the butterflies.

Sudden extreme weather events or incremental changes in temperature and rainfall affect their ability to breed and find food.

Intensive farming also plays a role in the declining populations. Notably, the use of pesticides harmful to butterflies has detrimental effects on Purple Hairstreaks.

These chemicals poison their food sources or directly kill them.

Lastly, the invasive species introduced into the butterflies’ habitats outcompete them for resources. With limited food and nesting sites, survival becomes a stiff competition that Purple Hairstreaks often lose.

Overall, the causes identified are:

  • Habitat loss due to urban development, deforestation, and agricultural intensification.
  • Climate change which impacts breeding and food sources.
  • Pesticides from intensive farming practices.
  • Competition from invasive species.

Preserving the Purple Hairstreak butterfly populations requires mindful practices such as maintaining their habitats, reducing pesticide use, and controlling invasive species.

By tackling these threats, we help ensure the existence of this beautiful creature for generations to come.


In summary, understanding the Purple Hairstreak Butterfly provides a unique lens on the fascinating world of lepidoptery.

Delving into its identification, life cycle, and varied behavior brings its natural wonder right into focus.

If you’ve enjoyed learning about this beautiful creature, please leave a comment with your thoughts or any further questions!

Butterflies   Updated: September 19, 2023
avatar Welcome to Insectic, a blog to learn about insects and bugs. I'm Richard, and I've created this website to share my experience, knowledge, and passion with others.

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