These insect cocoons were found in the Holocene deposits of Australia.. they are believed to be from the Weevil, Leptopius duponti. Analysis shows that these cocoons were made of sand or gravel with a secretion from the weevil larva. The larva lived underground feeding on the roots or underground stems. When fully fed it prepared to pupate by making a chamber, or cocoon, where it underwent the change from larva to adult beetle. Instead of spinning a cocoon like other insects, the larva makes a cell in the earth by tamping the soil around it to form a hard wall, perhaps exuding a secretion which makes the soil or sand set like concrete. The larva entered the pupal stage which may have lasted for months. The new adult then pushed its way through the cell wall and burrowed to the surface
