Biology: Why are cicadas released with urine – Wikiwand

Some leafhoppers have a huge amount of food. Day after day, they ejaculate up to 300 times their body weight in small drops of urine from their hind end. This is made possible by some kind of specialized device, like scientists led by Saad Bahmala of the Georgia Institute of Technology in the specialized magazine Nature Communications He writes. The researchers’ videos show how the tiny animals release tiny droplets roughly every second.

For comparison: according to researchers, the daily amount of feces in humans corresponds to an average of only about 2.5 percent of body weight.

The release of urine drops saves energy

According to the researchers, the cicadas (Homalodisca vitripennis), which are only a few millimeters in size, feed exclusively on the so-called xylem tissue from the water supply system of plants. The juice is very low in nutrients and consists almost entirely of water. Animals must suck up similarly large amounts of plant sap. They have an efficient digestive system that can filter and transport large amounts of plant secretions throughout their body. In order to then get rid of the water, these cicadas use a special mechanism that specifically accelerates the excreted droplets, the researchers write.

Perhaps the whole thing is a strategy for the cicadas to save energy, because with other methods of urine separation, energy consumption is significantly higher, write the researchers, who used several mathematical models for their study, among other things. Additionally, by throwing the droppings away, enemies will not easily realize where the cicadas are.