Common Imperial Blue

Common Imperial Blue

Jalmenus evagoras

Endemic
Daily sighting probability ~10% · With luck
at Royal National Park

In 3 days ~20% in a week ~40%

5 Verified sightings at Royal National Park From 2019 to 2026
45 In all 2 parks
March Best month
☀️ Diurnal When it's spotted

About the Common Imperial Blue

Jalmenus evagoras, the imperial hairstreak, imperial blue, or common imperial blue, is a small, metallic blue butterfly of the family Lycaenidae. It is commonly found in eastern coastal regions of Australia. This species is notable for its unique mutualism with ants of the genus Iridomyrmex. The ants provide protection for juveniles and cues for adult mating behavior. They are compensated with food secreted from J. evagoras larvae. The ants greatly enhance the survival and reproductive success of the butterflies. J. evagoras lives and feeds on Acacia plants, so butterfly populations are localized to areas with preferred species of both host plants and ants.

The wings of Jalmenus evagoras are metallic blue outlined with black. The hindwings have tails and orange spots towards the bottom. On the ventral side, wings are buff-coloured with black streaks and orange hindwing spots similar to the dorsal side. The butterfly has a maximum wingspan of 4 cm.

Little to no sexual dimorphism is observed between male and female adult butterflies. In the pupal stage, females can be up to 60% larger than males. Jalmenus evagoras lives along the east coast of Australia in... Wikipedia →

Global Distribution

Parks Where Found

# Park Country Daily sighting probability
1 Blue Mountains National Park 🇦🇺 Australia
~10%
2 Royal National Park 🇦🇺 Australia
~10%

Cities Where Found

# City Country Daily sighting probability
1 Brisbane 🇦🇺 Australia
~10%
2 Melbourne 🇦🇺 Australia
~10%
3 Sydney 🇦🇺 Australia
<5%

Before you go

What are the chances of seeing a Common Imperial Blue in Royal National Park?

With luck

About 10% of wildlife watchers report a Common Imperial Blue sighting in Royal National Park on a given day, based on 5 verified sightings from GBIF citizen-science data from 2019 to 2026. It is the 147th most-seen of the 175 insects we can rate there. Over three days the chance rises to about 20%, and over a week to about 40%, if each day is a fresh chance.

When is the best time to see a Common Imperial Blue in Royal National Park?

February–March and December

In those months about 10% of wildlife watchers report a Common Imperial Blue in Royal National Park on a given day, against under 5% in January and April–November, the lowest months.

What time of day is best to see a Common Imperial Blue?

Between 1 and 4 pm

Across all the parks we cover, that three-hour window holds the most Common Imperial Blue sightings with a recorded time, and about 9 in 10 of them come between 6 am and 6 pm: it is a daytime animal.

Is Royal National Park the best place to see a Common Imperial Blue?

Among the best

Of the 2 parks where we can rate Common Imperial Blue sightings, Royal National Park ranks 2nd at about 10%, level with the leaders once rounded. The best odds are in Blue Mountains National Park (Australia, about 10%).

Which relatives of the Common Imperial Blue live in Royal National Park?

Same family: Lycaenidae

The closest relatives of the Common Imperial Blue that you can see in Royal National Park (family Lycaenidae, Gossamer-winged Butterflies) are Lesser Grass Blue (about 10%), Zizina labradus (about 10%) and Small Green Banded Blue (about 10%), with each one's daily chance of a sighting.

Where does the Common Imperial Blue sighting chance come from?

GBIF citizen-science records

It is estimated from how often the Common Imperial Blue is recorded against all the insects logged in Royal National Park (5 verified sightings from 2019 to 2026), calibrated against known sighting rates. Figures are rounded to the nearest 10% because citizen-science data supports honest approximations, not decimals, and months with records from fewer than five people show "—". How it works.

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