Castor Semi-Looper

Castor Semi-Looper

Achaea janata

Daily sighting probability <5% · Rare
at Sydney

In 3 days ~10% in a week ~20%

5 Verified sightings at Sydney
37 In all 2 parks From 2019 to 2026
March Best month
☀️🌙 Day & Night When it's spotted

About the Castor Semi-Looper

Achaea janata, the castor semi-looper or croton caterpillar, is an erebid moth, the caterpillars of which are termed 'semi-loopers' due to their mode of locomotion. It is found from the Indo-Australian tropics and subtropics, extending south to New Zealand and east through the Pacific archipelagoes to Easter Island. It is a major pest of castor throughout the world.

Its wingspan is about 60–70 mm. The species has a pale reddish-brown body. Forewings with prominent markings. A short sub-basal waved line and an obliquely waved antemedial and excised postmedial lines are present. Postmedial lines are often black suffused inside them. A speck is found at the end of the cell. A diffuse rufous band runs beyond the postmedial line, Hindwings black with medial white band. Three large white spots can be seen on outer margin, with whitish cilia. Ventral side grey suffused. Forewings with an oblique white postmedial band not reaching the costa. Two crenulate medial lines found on each wing.

Eggs are small, spherical with a greenish color. Pupa is whitish green. Larva bluish grey speckled with blue black. Head black striped. Lateral and sub-lateral yellowish bands with intervening... Wikipedia →

Global Distribution

Parks Where Found

# Park Country Daily sighting probability
1 Daintree National Park 🇦🇺 Australia
~10%
2 Springbrook National Park 🇦🇺 Australia
~10%

Cities Where Found

# City Country Daily sighting probability
1 Jamshedpur 🇮🇳 India
~30%
2 Bengaluru 🇮🇳 India
~20%
3 Brisbane 🇦🇺 Australia
~10%
4 Ahmedabad 🇮🇳 India
~10%
5 Dhaka 🇧🇩 Bangladesh
~10%
6 Chennai 🇮🇳 India
~10%
7 Kolkata 🇮🇳 India
~10%
8 Hyderabad 🇮🇳 India
~10%
9 New Delhi 🇮🇳 India
~10%
10 Pune 🇮🇳 India
~10%

Before you go

What are the chances of seeing a Castor Semi-Looper in Sydney?

Rare

Under 5% of wildlife watchers report a Castor Semi-Looper sighting in Sydney on a given day, based on 5 verified sightings from GBIF citizen-science data. It is the 666th most-seen of the 742 insects we can rate there. Over three days the chance rises to about 10%, and over a week to about 20%, if each day is a fresh chance.

When is the best time to see a Castor Semi-Looper in Sydney?

Any time of year

In every month with enough records, under 5% of wildlife watchers report a Castor Semi-Looper in Sydney on a given day, so our monthly data shows no clear season.

What time of day is best to see a Castor Semi-Looper?

Between 9 pm and midnight

Across all the parks we cover, that three-hour window holds the most Castor Semi-Looper sightings with a recorded time, and about 6 in 10 of them come between 6 pm and 6 am: it is seen both by day and at night.

Is Sydney the best place to see a Castor Semi-Looper?

17th of 17

Of the 17 cities where we can rate Castor Semi-Looper sightings, Sydney ranks 17th at under 5%. The best odds are in Jamshedpur (India, about 30%), Bengaluru (India, about 20%) and Brisbane (Australia, about 10%).

Which relatives of the Castor Semi-Looper live in Sydney?

Same family: Erebidae

The closest relatives of the Castor Semi-Looper that you can see in Sydney (family Erebidae, Underwing, Tiger, Tussock, and Allied Moths) are White Cedar Moth (about 10%), White Antennae Wasp Moth (about 10%) and Lichen-Eating Caterpillar (about 10%), with each one's daily chance of a sighting.

Where does the Castor Semi-Looper sighting chance come from?

GBIF citizen-science records

It is estimated from how often the Castor Semi-Looper is recorded against all the insects logged in Sydney (5 verified sightings), 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.

← Back to Sydney