The Ox Beetle or Elephant beetle (Strategus aloeus) is the largest and most common beetle species found in the United States ranging from Florida to Arizona. In fact, this beetle is sometimes called (erroneously) the "Southwestern Ox Beetle", perhaps because of its prevalence in that area of the country. It also occurs southward into South America. Other common names are Eeastern Hercules Beetle and Elephant Beetle.
The Ox Beetle is relatively large (up to 2½ inches long) and colored yellowish or greenish-gray with brown to black spots. Rarely are they reddish-brown. The Ox Beetle's mouthparts are for chewing.
The name rhinoceros beetle has been used for this species as well as the close relatives. However, the name now appropriately is applied to Xyloryctes jamaicensis, a dark brown species about 1 inch long and with a single long upright horn on the head of the males. Females have a small tubercle instead of a horn. Xyloryctes jamaicensis larvae feed on roots of ash trees.
Interestingly, male Ox Beetles come in "major" and "minor" varieties. The major males have three large projections or horns on the thorax with the central one the longest. These horns are located behind the head (on the pronotum), resembling a triceratops, the three-horned dinosaur. Minor males have horns as well, but the two in back are small and stubby. Female Ox Beetles have no horns, per se, only a small raised area (tubercles) in place of the horns.
Adult Ox Beetles live between four to six months. They are active in the summer and dig deep holes in sandy soil that they use to hide in during the day. The adult stage do not seem to require much food. They eat apples and other types of fruit that are available, and may even eat leaves.
Adults are proficient diggers Females lay their eggs singly in anything from old middle-decayed wood to flake soil. They often add dried leaves to this earthy material to help promote protection and proper temperature, which results in more eggs hatching and maturing. The larvae or grubs grow very quickly, taking almost a year to develop. Pupation is affected by weather conditions and the long pupation period is shortened if the pupae are kept in a warmer environment.
Larvae look like large, white, C-shaped grubs similar to June beetles. Larvae live in rotten logs or high organic matter. They are also found in compost heaps and occasionally infest potting media. Hence, living inside wood blocks and the like, their diet consists of rotten wood and composted vegetation (decayed roots and leaves). Thus, they serve a vital role of recycling organic matter.
Ox beetles are easy to keep and are terrific beetles to play with. Don't forget to feed them the occasional apple slice. Ox beetles are easy to raise from egg to adult, but there is one catch – it is very difficult to get them to lay more than a couple eggs. (Remember females will only lay eggs in very sandy soil with old grass and rotten leaves. Without these conditions the female is unlikely to lay any eggs, but adding crushed leaves to the substrate may help egg production.)
Ox beetles are medically harmless and the worse thing that can be said about these benign creatures of nature is that their size and appearance may startle you. If you see an adult, please don't kill it. Ox beetles are important in recycling plant material back into the ecosystem.
Beneficials in the Garden & Landscape is an Earth-KindTM program coordinated through Extension Horticulture at Texas A&M University. Earth-Kind uses research-proven techniques to provide maximum gardening and landscape enjoyment while preserving and protecting our environment.
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