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These moths fly at night Scientists do not yet know how they do this

The used very complex technology to track the death’s-head hawkmoth.

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When provoked, Death’s-head hawkmoths can shriek. They have a pattern on their backs that mimics a human skull, and because of this, they made a lethal cameo in the movie The Silence of the Lambs. And now, the dreaded insects have assisted scientists in accomplishing a task that was once regarded as impossible.

Scientists were able to see moths performing their yearly southbound migration by equipping them with tiny temporary backpacks with radio-transmitters and releasing them at night.

The most remarkable flight route was that of a moth, the longest insect flight ever continually tracked, which flew from an airfield in Konstanz, Germany, more than 55 miles south into the Swiss Alps.

The death’s-head hawkmoth’s 2,400-mile migration from northern Europe to the Mediterranean coast and beyond—possibly as far south as sub-Saharan Africa—represents only a small piece of the newly discovered one-night trip. Typically, one generation of the moths leaves Europe in the fall to travel to their southern breeding grounds, and the following generation returns to Europe in the spring.

Death’s-head hawkmoths fly quickly compared to the majority of other insects, reaching maximum flying speeds of 43 miles per hour. However, to follow them in an aircraft moving at a considerably higher speed, the researchers flew in close succession while keeping an ear out for the unique woppp sound generated when the aircraft’s antennae picked up a moth more than a thousand feet below.

According to Martin Wikelski, director of the Max Planck Institute of Animal Behavior and senior author of a study that was just published in the journal Science, “With an antenna on each wing, it’s almost like you have two ears listening.”

Wikelski was able to operate the Cessna 172 while his colleagues dropped one to two moths on the ground below because he has experience flying. When Myles Menz, the study’s principal author, would announce over the radio, “Moths away,” he would know to begin listening for pings.

Similar tracking investigations on birds have been done, and Wikelski has successfully applied the technique to bats and dragonflies. But because death’s-head hawkmoths are larger than most common moths and have wingspans broader than the height of a Coke can, they have made significant strides in radio-transmitter technology.

According to National Geographic Explorer and butterfly migration specialist Gerard Talavera, who was not involved in the current study, “they have been attempting to do this with insects, and they finally achieved it.” “It is amazing to watch people performing such courageous job.”

“Absolutely straight” flight

The work has shown some intriguing characteristics of moth migration, which makes it impressive as a proof-of-concept that could be helpful in the study of other insects.

One such theory is that insects are blown off course by the wind as they migrate; this hypothesis makes sense given that even giant lepidopterans like death’s-head hawkmoths weigh less than an ordinary shirt button.

As a result, when Wikelski first took to the air, he used his onboard instruments to track the direction and speed of the wind and design a trajectory under the presumption that the moths would be blown in that direction. He immediately lost sight of the moths while doing this though.

The moths are still there, I noticed later, he says. No matter what the wind was doing, we noticed they were traveling straight ahead—absolutely straight ahead.

The scientists turned to the moths’ altitudes to learn how they managed the feat. The moths flew low to the ground, picking up speed when the wind blew in their faces. The animals increased their altitude to about 1,000 feet to better utilize the acceleration when the wind was at their backs, but did so at the expense of their airspeeds.

The moths seemed to be carefully balancing their sense of direction with their speed. The moth’s internal compass, like those of many other insects, is thought to be calibrated by a mix of magnetism, eyesight, and perhaps smell.

Another first for migratory insects was the moths’ ability to demonstrate “full compensation,” or keeping a straight path despite being attacked by various wind speeds and directions.

According to Wikelski, it appears that these insects have discovered a method for maintaining absolute accuracy in their navigational path. And that is really thrilling.

The future of insect tracking

The ability to follow individuals is revolutionary for researchers investigating insect migration since it will enable them to provide answers to issues that were previously speculative.

What do they eat, where do they stop, and at what pace can they fly? These were largely presumptions, although Talavera notes that several of these questions are now supported by actual facts for the first time.

Learning more about the trillions of migratory insects in the world is also important for practical reasons.

According to Wikelski, one in ten people are still impacted annually by desert locusts, which devour crops and cause famine and starvation. And that leads to serious interpersonal difficulties.

According to him, the capability to detect insects may one day aid in preventing the spread of invasive species, preserving endangered species like the monarch butterfly, and reducing the spread of diseases transmitted by insects.

It might occur sooner than you anticipate. Scientists will be able to track large individual insects like moths and dragonflies not just over the course of one night but as they fly all over the world thanks to a new pair of satellites that are expected to enter orbit in 2028 as part of a collaboration between NASA and European space agencies.

Indeed, moths have fled.