Cnaphalocrocis medinalis
In 3 days ~10% in a week ~30%
Cnaphalocrocis medinalis, the rice leafroller, is a species of moth of the family Crambidae. It is found in south-east Asia, including Hong Kong, Sri Lanka, Taiwan, Thailand and most of Australia. This moth typically has a wingspan of approximately 16 millimeters.
Its larvae are recognized as pests of various crops, including Oryza sativa, Zea mays, and Triticum, Saccharum and Sorghum species. The adult moth is characterized by its vibrant yellow or straw coloration, with distinct wavy lines visible on its forewings and hindwings. Eggs are usually laid individually or in groups on the undersides of leaves, appearing scaly and white. A female moth can lay around 56 eggs, with an incubation period lasting between 4 and 8 days. Larvae go through 5 to 6 instars over a period of approximately 22 to 23 days before pupating within folded leaves for about 6 to 7 days. Fully grown caterpillars are green and measure around 16.5 millimeters in length. The entire life cycle of this moth spans about 5 weeks.
Throughout its life stages, the rice leafroller can cause significant damage to crops. Newly hatched caterpillars initiate damage by cutting leaf edges and folding them. In the case of young seedlings, they may fold multiple adjacent leaves and consume the green tissue, leaving affected leaves with a whitish appearance. A single caterpillar can damage numerous leaves, leading to reduced plant vigor and eventual crop yield loss, which can range from 10% to 50%. This pest poses a more severe threat during the boot leaf stage of crop development. Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Lamington National Park | 🇦🇺 Australia |
More parks will be added in future updates.
Rare
Under 5% of wildlife watchers report a Rice Leaf-Roller sighting in Hong Kong on a given day, based on 26 verified sightings from GBIF citizen-science data. It is the 374th most-seen of the 1125 insects we can rate there. Over three days the chance rises to about 10%, and over a week to about 30%, if each day is a fresh chance.
April and September–October
In those months about 10% of wildlife watchers report a Rice Leaf-Roller in Hong Kong on a given day, against under 5% in May–August and November–March, the lowest months.
Between 7 and 10 pm
Across all the parks we cover, that three-hour window holds the most Rice Leaf-Roller sightings with a recorded time, and nearly all of them come between 6 pm and 6 am: it is mostly seen at night.
13th of 16
Of the 16 cities where we can rate Rice Leaf-Roller sightings, Hong Kong ranks 13th at under 5%. The best odds are in Jabalpur (India, about 20%), Vadodara (India, about 20%) and Prayagraj (India, about 10%).
GBIF citizen-science records
It is estimated from how often the Rice Leaf-Roller is recorded against all the insects logged in Hong Kong (26 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.
