Your average Joe assumes that insects defend themselves by biting with their mouthparts or by stinging with their stingers. It does not occur to most non-experts that insects vary just as much in their defensive features as they do in their physical features. Some insects have adapted to surviving on this planet by evolving excessively strange and complicated physical defense mechanisms that seem to defy logic. A particular group of sap-sucking insects provide an apt example of this sort of strangeness. A type of sap-sucking insect known as a “sharpshooter” uses a truly unique catapult-like physical feature to fling its urine for reasons that are still unknown. These insects are capable of flinging their urine at incredibly high speeds, and after years of research, scientists are finally able to understand how this insect achieves such an outlandish feat.
It is not unheard of for people to become doused with the urine of sap-sucking insects after walking near a tree infested with the seemingly mischievous insects. According to the engineer who led the recent study on how sharpshooter insects propel their urine, it is not known why these insects developed this odd ability, but it could be to avoid being exposed to their own urine, as the scent of urine can attract predators. The engineer who led the study, Saad Bhamla, of the Georgia Institute of Technology in Atlanta, recorded the urine-propelling behaviors of two sap-sucking species with high speed video footage in order to determine how these insects achieve such remarkable urine-speeds. The two species are commonly known as the glassy-winged sharpshooter and the blue-green sharpshooter. Video footage revealed that a tiny barb called a stylus, which is located at the insects’ rear, works like a spring to propel urine into the air. As soon as a drop of urine falls onto the stylus, the mechanism springs forth, launching the urine droplet into the air at an acceleration of 20 times that of earth’s gravity. The stylus is outfitted with tiny hairs that also work to launch the urine droplets into the air. Sharpshooting sap-suckers do a lot of damage to the natural environment, as they transmit bacteria that causes disease in plants. Unfortunately, sharpshooters have recently expanded beyond their native southeastern US habitat to infect vineyards in Northern California.
Have you ever found a sap-sucking insect in the wild?