Two broods of cicadas, numbering about a trillion, about to emerge in US
News and notes about science
In a rare occurrence, a trillion cicadas from two different broods are expected to begin appearing in the Midwest and Southeast regions of the United States at the end of April.
It’s the first time since 1803 that Brood XIX, or the Great Southern Brood, and Brood XIII, or the Northern Illinois Brood, will appear together in an event known as a dual emergence.
Thomas Jefferson was president the last time that the Northern Illinois Brood’s 17-year cycle aligned with the Great Southern Brood’s 13-year period in 1803. After this spring, it’ll be another 221 years before the groups, which are geographically adjacent, appear together again.
A roughly 16-state area will be center stage for these periodical cicadas, which differ from those that appear annually in smaller numbers.
Forested areas, including urban green spaces, are more likely to see higher numbers of cicadas than agricultural regions.
To put into perspective just how many of these bugs could emerge, 1 trillion cicadas, each just over 1 inch long, would cover 15,782,828 miles if they were placed end to end, said Floyd Shockley, an entomologist and collections manager at the Smithsonian National Museum of Natural History.
The first cicadas are expected to start emerging late this month. Temperature determines when they come out, said Gene Kritsky, a retired professor of biology at Mount St. Joseph University in Cincinnati, and the author of several books on cicadas.
Kritsky said that first the soil needed to reach 64 degrees Fahrenheit, about 6 inches deep, and “then you get a good soaking rain, and that’s when they really pop.”
They’ll use their forelegs to tunnel out from the earth, their beady red eyes looking for a spot where they can peacefully finish maturing.
A few days after they emerge and molt, the males will start buzzing in an effort to find a mate, a slow-building crescendo of noise that as a chorus can be louder than a plane.
— Aimee Ortiz
New method may curb illegal timber
Using a unique combination of old-fashioned fieldwork and sophisticated computer modeling, scientists in Sweden have found a way to trace a single beam of lumber to the forest in Europe where it originated.
The researchers said the new method, described in a recent paper in the journal Nature Plants, could significantly curb the sale of Russian timber, which is prohibited in the European Union because of the war in Ukraine. But birch, oak, pine and other types of lumber from Russia are still finding European buyers amid surging demand.
The novel approach was recently used to identify large shipments of illegal Russian lumber in Belgium.
The new study looked at the chemical composition of 900 wood samples collected from 11 countries in Eastern Europe. The data was fed into a model powered by machine learning, which found patterns that could predict the geographic origin of the samples.
Overall, the model caught 60% of the samples that had been intentionally labeled with the wrong country of origin. The model could also narrow the wood’s origin to a roughly 125mile radius, a remarkable feat in a continent that’s roughly 40% covered by forest. The method is “very, very solid from a technical point,” said Naren Ramakrishnan, a data scientist at Virginia Tech who was not involved in the research.
Under the direction of Victor Deklerck, a lead author of the study, researchers with Preferred by Nature, a nonprofit based in Copenhagen, Denmark, fanned out across Europe to collect tree samples by using a long, tubelike device that pulls out wood tissue. A tree is not harmed when a sample is extracted from its trunk, Deklerck said, because the rest of the organism “walls off” the wounded tissue.
The samples were analyzed for the minerals they pulled in from the soil, as well as elements, such as nitrogen and carbon, that they absorbed through rainfall. The result was a “chemical fingerprint” for each tree sample in the study, said Deklerck, who is also the chief scientist at World Forest ID, a nonprofit in Washington that fights deforestation.
— Alexander Nazaryan
How a snake uses its sense of smell
Say the words “animal self-recognition,” and many scientists will think of chimpanzees, crows and elephants. But now researchers have found evidence that garter snakes can distinguish themselves from others, using not sight but scent.
Noam Miller, a comparative psychologist at Wilfrid Laurier University in Ontario, Canada, and an author of a new paper in the journal Proceedings of the Royal Society B, said, “There’s a bias out there that they’re these boring, not very cognitive animals, and that’s completely wrong. ” One sign of cognition has been whether an animal can recognize itself in a reflective surface, a trait thought to be a proxy for more sophisticated intelligence. The test involves marking an animal with paint somewhere visible only in the mirror and waiting to see if it investigates the change.
Similar tests have been done with a range of species: elephants (passed), pandas (failed) and roosters (passed). But the mirror test is geared toward animals that are primarily visual. Many species — such as snakes — rely mostly on their sense of smell.
Two species of snakes were tested: North American eastern garter snakes (predators of insects and fish) and African ball pythons (largely solitary snakes that ambush rodents).
Snakes, like humans, have oils in their skin that leave a scent trail. The team rubbed makeup removal pads along the snakes’ undersides to collect scent samples, some of which they doctored with olive oil. They placed the pads at either ends of narrow boxes and offered the snakes choices between their own odor and straight olive oil; their own odor modified with olive oil; and the modified or unmodified odors of other snakes of the same species.
The snakes’ interest was measured by gauging how long they flicked their tongues to taste the air — longer indicated sustained interest. The ball pythons showed no apparent distinction. But the garter snakes zeroed in on their own tampered smell and ignored variations of the other snakes’ smells.