From Nookipedia, the Animal Crossing wiki
Donating to the Museum
As with all insects in the Animal Crossing series, the Tiger Beetle can be donated to the Museum followed by a small talk by Blathers, the curator. A sign in the bug exhibit displays information about the Tiger Beetle.
In New Leaf
"Tiger beetles are known for their aggressive predatory habits and fast running speed. Their bodies are rather colorful and reflect the sunshine, giving them a shimmery appearance. Tiger-beetle larvae live in cylindrical burrows and capture insects that wander past with their mandibles."
It can be found in the top section of the upper right room in the bug habitat of the museum.
Names in other languages