Scarab beetle

The scarab beetle (プラチナコガネ, Purachina kogane) is a rare insect that appears in the. It looks like a Fruit Beetle in size and shape, with only the golden color separating it. It can be sold for 6,000 Bells.

In
Upon donation to the Museum, Blathers the curator will say;

"From the gorgeous to the grotesque, the fruit-beetle family has a wide variety of members, indeed... Among them, the shiniest by far is the scarab beetle. Not that it makes any bit of difference to me. If it has antennae, it's most unconscionably vile..."

It can be found on the top terrace of the insect exhibit, on the second cedar trip from the right - sharing it with the Fruit Beetle.

Encyclopedia Information
In and Animal Crossing: City Folk, players can access information about fish and insects in the menu. Regarding the scarab beetle:

Further Information
The Plusiotis resplendens (also known as Golden Scarab Beetle or Jewel Scarab Beetle) gets the name from its elegant, metallic body, which is said to "gleam like gold." They are native to the Americas, unlike the common idea of the location for scarabs, which is Egypt (where they were made famous). They sell for alarmingly high prices. The young larva form can be found living in rotten logs, while the adults are found living on foliage. Common colors for jewel scarabs are green, silver, and gold.