When I went out to check the water troughs this morning, I was delighted to find a Diamond Weevil (Chrysolopus spectabilis) perched on a Silver Wattle. This gorgeous bug is also commonly known as the Botany Bay Diamond Weevil or the Sapphire Weevil. I like weevils. They look like tiny, humble elephants, with their lumbering gait and long snouts.
Weevils are the most successful and abundant family of creatures on earth. There are estimated to be over 10,000 species in Australia alone, with only 5,000 having been named. The Diamond Weevil has a proud history. A specimen was collected by Joseph Banks at Botany Bay during Cook’s voyage of discovery in 1770. It was the very first Australian insect to be scientifically described.
Diamond Weevils are specialist feeders, living only on a few species of wattle. Females lay eggs inside the stems. They hatch into grubs which feed on roots and then undergo metamorphosis. The adults or imagines (what a lovely name!) emerge during spring in all their brilliance. They are black, but beautifully patterned with palest, iridescent green. Put a Diamond Weevil on your hand, and it it so bright and shiny, one wonders how it ever escapes predators. But back on on the feathery, silver-green foliage of the Silver Wattle, it is surprisingly hard to see. The map above shows the distribution of the Diamond Weevil on mainland Australia.