Grass Demon

Grass Demon

Udaspes folus

Daily sighting probability ~20% · Possible
at Tuen Mun

In 3 days ~50% in a week ~80%

100 Verified sightings at Tuen Mun
6 In 1 park From 2019 to 2026
September Best month
☀️ Diurnal When it's spotted

About the Grass Demon

Ancistroides folus, the grass demon, is a small but prominent butterfly found in India & Nepal that belongs to the skipper family, Hesperiidae. It is regarded as an occasional pest of ginger and turmeric plants. Male. Upperside black, the basal half of both wings covered with minute yellowish scales, markings pure white, semi-hyaline. Forewing with a large white spot filling up the end of the cell, two similar conjoined spots outwardly below it extending from beneath vein 4 to the sub-median vein, hardly separated from each other by vein 2; four conjugated sub-apical spots, the uppermost one minute, two similar spots below them nearer the outer margin, a small spot between these and the two large conjoined spots. Hindwing with a very large medial white patch with its margin sinuous all round; abdominal area covered with yellowish hairs. Underside paler. Forewing with the markings as on the upperside. Hindwing with the white medial patch extending to the abdominal margin from near the costa to one-third above the anal angle, the extension suffused with grey, also extending narrowly to the outer margin, double blackish-brown lunular marks, within the white space at... Wikipedia →

Global Distribution

Parks Where Found

# Park Country Daily sighting probability
1 Kanha National Park 🇮🇳 India
~10%

More parks will be added in future updates.

Cities Where Found

# City Country Daily sighting probability
1 Kozhikode 🇮🇳 India
~20%
2 Tuen Mun 🇨🇳 China
~20%
3 Jabalpur 🇮🇳 India
~20%
4 Thrissur 🇮🇳 India
~20%
5 Coimbatore 🇮🇳 India
~20%
6 Thiruvananthapuram 🇮🇳 India
~20%
7 Mumbai 🇮🇳 India
~20%
8 Kochi 🇮🇳 India
~20%
9 Bengaluru 🇮🇳 India
~20%
10 Ponnani 🇮🇳 India
~20%

Before you go

What are the chances of seeing a Grass Demon in Tuen Mun?

Possible

About 20% of wildlife watchers report a Grass Demon sighting in Tuen Mun on a given day, based on 100 verified sightings from GBIF citizen-science data. It is the 36th most-seen of the 557 insects we can rate there. Over three days the chance rises to about 50%, and over a week to about 80%, if each day is a fresh chance.

When is the best time to see a Grass Demon in Tuen Mun?

August and September

In those months about 40% of wildlife watchers report a Grass Demon in Tuen Mun on a given day, against under 5% in January and February, the lowest months. Those are among Tuen Mun's wettest months, with about 200 mm of rain a month against 20 mm in December.

What time of day is best to see a Grass Demon?

Between 9 am and noon

Across all the parks we cover, that three-hour window holds the most Grass Demon sightings with a recorded time, and nearly all of them come between 6 am and 6 pm: it is a daytime animal.

Is Tuen Mun the best place to see a Grass Demon?

Among the best

Of the 26 cities where we can rate Grass Demon sightings, Tuen Mun ranks 2nd at about 20%, level with the leaders once rounded. The best odds are in Kozhikode (India, about 20%).

Which relatives of the Grass Demon live in Tuen Mun?

Same family: Hesperiidae

The closest relatives of the Grass Demon that you can see in Tuen Mun (family Hesperiidae, Skippers) are Indian Palm Bob (about 20%), Formosan Swift (about 20%) and Chestnut Angle (about 10%), with each one's daily chance of a sighting.

Where does the Grass Demon sighting chance come from?

GBIF citizen-science records

It is estimated from how often the Grass Demon is recorded against all the insects logged in Tuen Mun (100 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.

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