First report of dorsal navigation of flying bugs

Under this shadow, the entrances to the beehives are lined up and various patterns can be seen. As the bees left the nest looking for food, the researchers rearranged the order of the nests, and when the bees returned, they were able to clearly find the nests based on the shadow pattern. Photo credit: Sandra Chaib

People who tend to get lost in the extraordinary darkness of tropical forests have a great deal to learn from bees, who can find their way home in starlight ten times as weak. Researchers at the Smithsonian Tropical Research Institute (STRI) research station on Baro Colorado Island in Panama and Lund University in Sweden (Megalopta genalis), use your dorsal vision to find a way home based on the pattern of the canopy. This first report on flying insect dorsal navigation Current Biology, it might be of particular interest to manufacturers of drones and other night-flying vehicles.

“One of the pioneers in researching bee homing behavior was Charles H. Turner, an African-American scientist at the University of Chicago,” said William Wcislo, a research fellow at STRI on the way home, and they say they nest to form a memory image of the topographical surroundings of the building. But what we didn’t understand until now was that the clues that bees remember were not only above their heads but also in front of their faces. “

Why Nobody Knows Bee On the island of Baro Colorado, she wanders from flower to flower like a crepuscular cat and only collects pollen about 70 minutes before sunrise and after sunset. Especially on tropical soils, where bees live in dead twigs and tendrils that are 100 times darker than above. Canopy..

Eric Warrant and his Vision Group team at Lund University in Sweden have been working with Wcislo since the late 1990s to learn more about Megalopta’s lightweight superpowers. Their study showed that Megalopta’s special compound eye was 30 times more sensitive to light and focused light photons, which the eyes of flying honeybees could not do during the day. By identifying pollen from the body and nest of honeybees, we found that honeybees collect pollen from more than 60 species of plants.

This powerful experiment showed that the bees chose the wrong nest when rotating the canopy pattern on the roof tile. Photo credit: Sandra Chaib

“To human observers, the most obvious visual cue in the night forest is the gap in the canopy when looking straight up, as the sky is much brighter than the forest below,” Warrant said. -Cross the branches, but the bee’s view is not that complicated. You can see a large mass of light with different shapes and positions. I was wondering because ants knew they could walk in the forest with the canopy pattern. When the bees do the same. “

Bees can’t, but to find out if the megaloptic bees have another superpower, Lund University student Sandra Chives moved to Baro Colorado to do an experiment.

To test this idea, Sandra first set up a special bee motel. Imagine the entrance to five rooms. Each entrance is the same circular gray disc. The door is a small round opening in the middle of the pane, at the end of the barnest.

In the first experiment, she asked if bees could find a way home with a single landmark. She placed a black bar over an entrance to the nest. She rearranged the nests after the bees left to look for pollen, but the actual nests were still marked with a black bar above the entrance. When the bees returned, they chose the right nest.

The bee Megaloptagenalis can be seen even in very dark places. This study by M. genalis is the first report on the use of back navigation by flying insects. Photo credit: Ajay Narendra

Then she made it a little more complicated by building some sort of canopy, like the roof of a carport, over the entrance to each nest. She placed an umbrella with a pattern of black and white bars over four empty nests and another pattern over the occupied nests. When the bees went out, she repositioned the nest, and when they returned they found the right nest again. However, she hasn’t ruled out the possibility of bees using other cues, such as their sense of smell, to find their nests. So she left the nest in the same place, but put the pattern the bees had learned on the empty nest … and the bees chose the empty nest and put the pattern in place of smell or other signals. Nest that showed it was used as a guide.

Her last experiment was the most elegant. This time the two nests shared a common awning. This is a light background bear design that depicts the light and dark patterns of a real forest roof. The entrance to the empty nest was at one end of the shade and the entrance to the occupied nest was at the other end. This time, when the bees were gone, Sandra turned the parasol upside down and reversed the pattern. Bees have a greater than 80% chance of choosing the wrong nest and have only shown once that they navigate according to the above pattern.

Understanding how Megalopta navigates can be interesting for military applications. Currently, most drones use GPS for navigation, but GPS and satellites can be disrupted or destroyed.

“Animals navigate with a multitude of clues. Vision is clearly very important, but many animals have magnetic sensation, which measures the properties of the Earth’s magnetic field and anywhere on the Earth’s surface. Or you can find out the direction. You have already learned about insects and other animals that can use stars to navigate. Pigeons can use scents to navigate … there are several clues. The canopy is one of the drones. You can navigate with a hint, but a very robust navigation system uses different cues like animals to navigate with all of these systems at the same time. “

The STRI facility is still closed due to COVID-19 restrictions, but researchers say, “So far, when the bees return home, all the bees know is how to identify the bee motel in their room. Not me. “We still don’t know how they move through the forest after they leave the nest.”

Large bumblebees start working early

For more informations:
Sandra Chaib et al., Dorsal Landmark Navigation in Neotropical Nocturnal Bees, SSRN E-Journal (2021). DOI: 10.2139 / ssrn.3805162

Provided by
Smithsonian Tropical Research Institute

Quote: The first report on back navigation of flying insects (June 17, 2021) is from https://phys.org/news/2021-06-dorsal-insect.html on June 17, 2021. Received.

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