June, 2010

Ox Beetle

Large insects are always impressive, but this massive beetle is a real head-turner. The ox beetle (Strategus aloeus) is a common inhabitant of compost bins and neglected wood piles in the Austin area. A kind of scarab, the 1.5 inch long ox beetle has equally sizeable grubs, which look much like the small white grubs that are a pest of lawns and gardens but can cover the palm of one's hand. These big larvae are most often seen when digging in compost that contains bits of branches or wood scraps; most of their diet consists of dead wood. This nutrient-poor diet means that the grubs grow slowly and take months to mature, at which point they become a pupa with a distinctive orange color. The pupae may be easily damaged by shovels, which makes me loathe to dig in our own compost bins.

Female ox beetles do not have the horns that are found on males. They are usually seen near suitable grub habitat because they are there to lay eggs. Males are sometimes attracted to lights. Although the beetles have functional wings, they don't fly often, and then it is the males that are more likely to take wing in order to seek females. These beetles reportedly feed on fruit and other sweet substances but I've never seen them attracted to sap or flowers like other scarabs.