A ball bearing is a type of rolling-element bearing that uses balls to maintain the separation between the bearing races.
The purpose of a ball bearing is to reduce rotational friction and support radial andaxial loads. It achieves this by using at least two races to contain the balls and transmit the loads through the balls. In most applications, one race is stationary and the other is attached to the rotating assembly (e.g., a hub or shaft). As one of the bearing races rotates it causes the balls to rotate as well. Because the balls are rolling they have a much lower coefficient of friction than if two flat surfaces were sliding against each other.
Members of the genus Bocydium are found only in the northern half of South America. The various species range from 4.6 to 7.5 mm in length (Godoy et al., 2006).
The purpose of the balls on the pronotal extensions has not been definitively explained.
Bocydium globulare is a solitary species. These hoppers are most often found feeding on the undersides of Glory Bush leaves (Miconia spp.) a couple of meters above the forest floor. The species is also attracted to lights.