Posts Tagged ‘entomology’
“If all insects disappeared, all life on earth would perish. If all humans disappeared, all life on earth would flourish.”
As Lars Chittka explains, insects have surprisingly rich inner lives—a revelation that has wide-ranging ethical implications…
In the early 1990s, when I was a Ph.D. student at the Free University of Berlin modeling the evolution of bee color perception, I asked a botany professor for some advice about flower pigments. I wanted to know the degrees of freedom that flowers have in producing colors to signal to bees. He replied, rather furiously, that he was not going to engage in a discussion with me, because I worked in a neurobiological laboratory where invasive procedures on live honeybees were performed. The professor was convinced that insects had the capacity to feel pain. I remember walking out of the botanist’s office shaking my head, thinking the man had lost his mind.
Back then, my views were in line with the mainstream. Pain is a conscious experience, and many scholars then thought that consciousness is unique to humans. But these days, after decades of researching the perception and intelligence of bees, I am wondering if the Berlin botany professor might have been right.
Researchers have since shown that bees and some other insects are capable of intelligent behavior that no one thought possible when I was a student. Bees, for example, can count, grasp concepts of sameness and difference, learn complex tasks by observing others, and know their own individual body dimensions, a capacity associated with consciousness in humans. They also appear to experience both pleasure and pain. In other words, it now looks like at least some species of insects—and maybe all of them—are sentient.
These discoveries raise fascinating questions about the origins of complex cognition. They also have far-reaching ethical implications for how we should treat insects in the laboratory and in the wild…
Insects are key enablers of much life on earth. They appear to exhibit intelligence, and maybe more: “Do Insects Feel Joy and Pain?” in @sciam.
Bugs are not going to inherit the earth. They own it now. So we might as well make peace with the landlord.
– Thomas Eisner
Pair with this helpfully skeptical (but respectful) review of Chittka’s book, The Mind of a Bee.
* Jonas Salk
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As we ponder our place, we might recall that it was on this date in 1897 that physician Sir Ronald Ross made a key breakthrough when he discovered malaria parasites while dissecting a mosquito. This day is now known as World Mosquito Day, in celebration of his critical discovery.
“Look deep into nature, and then you will understand everything better”*…
Philip Ball unpacks the geometric rules that define eyes, honeycombs, and soap bubbles…
How do bees do it? The honeycombs in which they store their amber nectar are marvels of precision engineering, an array of prism-shaped cells with a perfectly hexagonal cross-section. The wax walls are made with a very precise thickness, the cells are gently tilted from the horizontal to prevent the viscous honey from running out, and the entire comb is aligned with the Earth’s magnetic field. Yet this structure is made without any blueprint or foresight, by many bees working simultaneously and somehow coordinating their efforts to avoid mismatched cells.
The ancient Greek philosopher Pappus of Alexandria thought that the bees must be endowed with “a certain geometrical forethought.” And who could have given them this wisdom, but God? According to William Kirby in 1852, bees are “Heaven-instructed mathematicians.” Charles Darwin wasn’t so sure, and he conducted experiments to establish whether bees are able to build perfect honeycombs using nothing but evolved and inherited instincts, as his theory of evolution would imply.
Why hexagons, though? It’s a simple matter of geometry. If you want to pack together cells that are identical in shape and size so that they fill all of a flat plane, only three regular shapes (with all sides and angles identical) will work: equilateral triangles, squares, and hexagons. Of these, hexagonal cells require the least total length of wall, compared with triangles or squares of the same area. So it makes sense that bees would choose hexagons, since making wax costs them energy, and they will want to use up as little as possible—just as builders might want to save on the cost of bricks. This was understood in the 18th century, and Darwin declared that the hexagonal honeycomb is “absolutely perfect in economizing labor and wax.”
Darwin thought that natural selection had endowed bees with instincts for making these wax chambers, which had the advantage of requiring less energy and time than those with other shapes. But even though bees do seem to possess specialized abilities to measure angles and wall thickness, not everyone agrees about how much they have to rely on them. That’s because making hexagonal arrays of cells is something that nature does anyway…
More at: “Why Nature Prefers Hexagons,” from @philipcball in @NautilusMag.
* Albert Einstein
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As we study structure, we might spare a thought for Agostino Bassi; he died on this date in 1856. An entomologist, he discovered that the muscardine disease of silkworms was caused by a very small parasitic organism, a fungus that would be named eventually Beauveria bassiana in his honor. The insight led him to argue that not only animal (insect), but also human diseases are caused by other living microorganisms (e.g., measles, syphilis, and the plague)– meaning that he preceded Louis Pasteur in the discovery that microorganisms can be the cause of disease (the germ theory of disease).
“Am I as admirable as that ant?”*…
There are lots of ants on earth. And, as Anna Turns explains, they play a big role as ecosystem engineers– as well as providing insights on everything from the climate to aging…
To most of us, they are small, uninteresting and sometimes annoying, but 2022 revealed just how ubiquitous ants are and how indispensable they are to the planet. Scientists revealed in September that there are an estimated 20 quadrillion (or 20 million billion) ants globally – that’s 2.5 million for every person on the planet.
More than 12,000 known species of ant live in all sorts of habitats, from the Arctic to the tropics and they represent one of the most diverse, abundant and specialist groups of animals on the planet. Leafcutter ants are fungus farmers, slave-making ants capture broods to increase their work force, while wood ants herd aphids to the juiciest parts of a plant to harvest their honeydew sap…
Experts agree that ants are ecosystem engineers because they play a crucial role in decomposing organic matter, recycling nutrients, improving soil health, removing pests and dispersing seeds. But, historically, ants haven’t attracted as much attention as crop pollinators, such as bees, which perhaps have more of an obvious economic value. That bias could soon change. Ants have been used as a biological pest control on citrus crops in China for centuries, and research published in August indicates that the pest control potential of some predatory ants could work better than some agricultural chemicals.
The wonders of ant biology throw up plenty of other possibilities for real-world applications. Queen ants that live more than 30 years – yet have the same genetic material as a short-lived worker ant – could teach us something about senescence. Nobody understands how queens store sperm for decades inside their bodies without any degradation, despite colonies living in different climates. Meanwhile, Schultheiss’ [Dr Patrick Schultheiss, of the University of Würzburg] research into ant navigation – how they find food and how they behave when they get lost – could help build mathematical models that instruct a robot searching for missing people.
Looking back at how ants evolved can shed light on a huge array of other plants and animals, too. Butterflies that rely on ants to tend to their caterpillars could disappear if those ants are wiped out, says Corrie Moreau, a professor at Cornell University: “Nature is this intricate woven tapestry and if you pull one thread, you’ll never know which is the critical thread that makes the whole thing fall apart.”…
“Insects and us: a mind-blowing 20 quadrillion ants and what they mean for the planet,” from @AnnaTurns in @guardian.
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As we get antsy, we might spare a thought for Swedish botanist Carl Linné, better known as Carolus Linnaeus, “the Father of Taxonomy,” died on this date in 1778. Historians suggest that the academically-challenged among us can take heart from his story: at the University of Lund, where he studied medicine, he was “less known for his knowledge of natural history than for his ignorance of everything else.” Still, he made is way from Lund to Uppsala, where he began his famous system of plant and animal classification– still in use today.
“If locusts are ravenous sociopaths, cicadas are more like frat boys – clumsy, loud, and obsessed with sex”*…
… and they are, themselves, the object of other species’ obsessions…
This spring’s emergence of periodical cicadas in the eastern U.S. will make more than a buzz. Their bodies—which will number in the billions—will also create an unparalleled food fest for legions of small would-be predators, including many birds and mammals. But some animals may benefit more than others, and any boost predator populations get from the coming buffet of winged insects will likely be short-lived, researchers say.
Tiny chickadees and mice have been known to wrestle these chunky bugs for a quick snack. Raptors, fish, spiders, snakes and turtles will gulp them down when given the chance. Captive zoo animals, such as meerkats, monitor lizards and sloth bears, will do so as well if the insects show up in their enclosure. Observers have even reported seeing domestic cats trap two cicadas at once, one under each forepaw.
This spring, three species of cicadas (collectively referred to as Brood X or Brood 10) will crawl out of the ground where they have spent the previous 17 years. They will coat the limbs and leaves of trees, sing, mate, lay eggs and then die. Uneaten corpses and body parts will add nutrients to the soil, bolstering the ecosystem and its denizens long after the boisterous insects disappear. But the famous periodicity of cicada broods can set some predators up for feast-then-famine scenarios—population booms followed by food insecurity and then sudden drops in numbers.
“In response to this superabundance of food, a lot of the predator populations have outrageously good years,” says Richard Karban, a University of California, Davis, entomologist who studies periodical cicadas. “But then the next year, and in the intervening years, there’s no food for them, so their populations crash again.”
Predators could be part of the reason that these slow-flying, defenseless and colorful cicadas emerge periodically instead of perennially. Over millennia, synchronized periodic emergences as a dense mob could have led to higher adult survival rates. Thus, the insects evolved to adopt their unusual life cycle—most of which is spent feeding underground—explains University of Connecticut evolutionary biologist and ecologist Chris Simon, who studies cicadas. “The predators are really important in driving the whole story,” she says. The success of the species effectively banks on sheer volume…
Most bird species do not travel to take advantage of cicada emergences… They live and eat in the same areas year after year, picking off the insects opportunistically instead of traveling to the cicada motherlode… cuckoos are an exception: they migrate to take advantage of insect outbreaks all over the country…
Despite all the eager predators, the life-cycle gamble on high-volume emergences pays off for periodical cicadas. Most survive predation to mate and then drop dead to the forest floor. But even if they go uneaten, their ecosystem impact does not stop there. Cicada bodies contain about 10 percent nitrogen, which is more than the concentration found in dead leaves and other typical forest litter, says Louie Yang, a University of California, Davis, entomologist, who studies resource pulses and phenological shifts. Plants such as American bellflowers will take up the nitrogen from the dead cicadas, and herbivorous mammals and insects will selectively feed on the higher-nitrogen fertilized leaves, he adds.
Patterns such as this one illustrate the ecological lens that periodical cicadas can provide on biological communities and evolutionary timelines. “I love the reciprocity of the whole system,” Yang says. “I think this kind of stuff happens all the time, but it’s usually hard to see. When these pulse events happen, it makes it really obvious—we can see that pulse pass through the system.”…
Billions of emerging insects will likely trigger predator population surges: “Brood X Cicadas Could Cause a Bird Baby Boom.”
Oh, and given climate change, 17-year cicadas could become 13-year cicadas: “The cicadas are coming. And they’re changing dramatically.”
* Catherine Price, 101 Places Not to See Before You Die
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As we bear the buzz, we might recall that it was on this date in 1923 that insulin became publicly available for use by diabetics. Frederick Banting had discovered insulin in 1921, and refused to put his name on the patent. He felt it was unethical for a doctor to profit from a discovery that would save lives. He and his co-inventors, James Collip and Charles Best, sold the insulin patent to the University of Toronto for a mere $1. They wanted everyone who needed their medication to be able to afford it.
Today, Banting and his colleagues would be spinning in their graves: Their drug, which many of the 30 million Americans with diabetes rely on, has become the poster child for pharmaceutical price gouging.
The cost of the four most popular types of insulin has tripled over the past decade, and the out-of-pocket prescription costs patients now face have doubled. By 2016, the average price per month rose to $450 — and costs continue to rise, so much so that as many as one in four people with diabetes are now skimping on or skipping lifesaving doses…
“There is no frigate like a book to take us lands away”*…
Nor indeed, to transport pests, it seems…
In Micrographia, a “study of the Minute Bodies made by the Magnifying Glass”, London, MDCLXVII, one of the earliest publications issued under the authority of the newly-formed Royal Society, Robert Hooke described in Observation LII the “small silver-colour’d Book-worm”, “which upon the removal of Books and Papers in the Summer, is often observed very nimbly to scud, and pack away to some lurking cranny”. The third figure of the 33rd scheme pictures a monster so formidable-looking that Blades ( may be forgiven the suggestion that Hooke “evolved both engraving and description from his inner consciousness”… [source]
Bookworm (Fig. 3, top) in Hooke’s Micrographia
But as later observation confirmed, Hooke was on the money… Sir William Osler, Regius Professor of Medicine at Oxford and one of the board of trustees of the Bodleian Library — called the Curators — of the Library reported in the first Volume of the Bodleian’s Quarterly Record…
‘In October 1915 I received from a Paris bookseller, M. Lucien Gougy, three volumes of the Histoire abregie de la derniere persecution de Port-Royal. Edition Royale, MDCCL.’ In one of the volumes Osler found a living book-worm, of species Anobium hirtum, ‘not a native of England, but met with occasionally in the centre and south of France.’
In true scientific fashion, Osler arranged for a portrait of the larva [the image at the top of this post] to be made by Horace Knight, natural history illustrator of the British Museum. Knight sent the picture in September 1916, apologising that he had ‘been waiting in hopes the larva would pupate, but it has not even commenced to make a case…’.
Bookworms and the Bodleian: “The Bodleian Quarterly Record, Vol. I (1914-16); and Osler’s ‘Illustrations of the book-worm’.”
* Emily Dickinson
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As we devour books, we might recall that it was on this date in 1890 that Alfred Harmsworth published the first edition of Comic Cuts, the first British weekly comic paper. A savvy publicist, Harmsworth relentlessly advertised the then-amazing fact that his paper was only a halfpenny an issue. Indeed in his manifesto in the first issue he wrote:
How is it possible for any one to provide an illustrated paper… for a halfpenny? Well, it is possible to do it, but that is all. I feel sure that the public will appreciate the fact that they are getting full value for their money, and will therefore buy the paper in immense numbers weekly.
And indeed his comic book was published from 1890 to 1953, lasting for 3006 issues– during which time it inspired the birth of an industry, as other publishers began to emulate him, producing rival comic magazines.
Vol 1, No 1 (source and larger version)
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