Are thrips really the indicator of thunderstorms?

Although there are over 6,000 different species of thrips, their tiny size means they are often overlooked, except when there is an approaching thunderstorm.

Thunderstorm creatures, also known as thrips or fringed wing insects, are often little, black, and very unpleasant. They are often called thunderflies, thunderbugs, storm flies, thunderblights, or storm bugs. These tiny insects, which rarely exceed 0.12 inches (3 millimeters) in length, seem to arrive en masse if the weather is hot and humid and a rainstorm is on the horizon. Although there are over 6,000 different species of thrips, their tiny size means they are often overlooked.

When thrips cluster in thousands

They cluster together in the thousands, resembling dark clouds, which are unpleasant for anybody who is caught in them because the thrips fall on any exposed skin and also in the nasal passages, oral cavity, and eyes, producing a crawling, itchy sensation. But may the reason for their mass hording be the approaching thunderstorm? Are they really suitable as thunderstorm indicators? If that’s the case, then how can thrips anticipate the arrival of a thunderstorm?

On hot, humid summer days, several species of thrips are known to engage in swarming flights. Temperatures over 70 degrees Fahrenheit (20 degrees Celsius) and stable, unchanging climatic conditions trigger the huge swarming of thrips. Thrips may rapidly become a nuisance when they emerge in masses, landing on humans and being drawn to all bright colors. When it’s hot and steamy outside, humans sweat, and thrips lick this perspiration off their skin and sometimes even bite through it. This causes irritation and, in really sensitive individuals, skin inflammation.

Humans as landing pands

But the thunderstorm is not the cause of thrips’ mass presence. Instead, the little insects, which are normally dispersed across the skies, settle on the ground in a coordinated effort when a storm is approaching. So they cluster around the places where people like us go and even utilize us as landing pads.

Thus, an increase in the number of thrips in the lower levels of the atmosphere may actually be an indicator of an approaching thunderstorm.

Electric field as a thunderstorm indicator

However, how can thrips know when a storm is about to hit the area? This is related more to a physical phenomenon than the weather itself. This is because electrically charged thunderclouds also alter the atmospheric electric field. Thunderstorms may produce electric fields as strong as 15 kilovolts per foot (kV/ft) (50 kilovolts per meter), compared to the typical 0.03 kV/ft (0.1 kV/m).

Research on fruit flies and other insects demonstrates that strong electric fields may cause thrips to lose control of their flight and become disoriented. For instance, British thrips researcher William Kirk believes that tiny insects like thrips, in particular, are impacted by variations in electric field strength and are no longer able to fly at roughly 2.4 kV/ft (8 kV/m) and beyond. So this electric charge might also be responsible for the sudden swarms of thrips that arrive near the ground just before a rainstorm. In most cases, though, it appears that thrips swarms are indicators of an impending storm.

By Bertie Atkinson

Bertie Atkinson is a history writer at Malevus. He writes about diverse subjects in history, from ancient civilizations to world wars. In his free time, he enjoys reading, watching Netflix, and playing chess.