Japanese Beetle: a two-minute wildlife lesson

Beetles and Friends · day 4 of 7

Five facts

1. At home in Japan, natural enemies keep it in check. But in North America and parts of Europe, it feeds on about 300 kinds of plants.
2. It is about 15 mm long, with shiny copper wing covers, a green head and little tufts of white hair along each side.
3. It eats only the soft parts between a leaf's veins, leaving behind a lacy skeleton of a leaf.
4. It spends most of its life as a grub in the soil. The shiny adult only lives for about 30 to 45 days.
5. Its grubs are thought to have reached the United States as stowaways in a shipment of iris bulbs, before 1912.

The quiz

1. Why is the Japanese beetle not a pest in Japan?

• It is too cold there
• Natural predators keep it in check (correct)
• It only eats weeds there
• It sleeps all year there

Natural predators in Japan stop it from becoming a pest.

2. What colour are the Japanese beetle's wing covers?

• Bright yellow
• Black with red dots
• Shiny copper (correct)
• Pure white

It has iridescent copper wing covers and a green head.

3. What does a leaf look like after Japanese beetles feed on it?

• A lacy skeleton of veins (correct)
• Rolled into a tube
• Covered in white wax
• Completely untouched

They eat only the tissue between the veins.

4. About how long does an adult Japanese beetle live?

• About 2 days
• About 10 years
• About 5 years
• About 30 to 45 days (correct)

Most of its life is spent as a grub; the adult lives about 30 to 45 days.

5. How is the beetle thought to have first reached the United States?

• Flying across the ocean
• On the feathers of birds
• Hidden in a shipment of iris bulbs (correct)
• Frozen in ice

Its grubs probably arrived in iris bulbs before 1912.

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