Floral-Scented Pesticide Lures Mosquitoes to Their Death

iStock
iStock

There are those who argue that mosquitoes serve a purpose, that their droning, blood-gorging presence represents an important link in a fragile food chain. Then there's Agenor Mafra-Neto, who mostly just wants them to die. The chemical ecologist and his colleagues presented their new strategy for mosquito control at the 254th National Meeting & Exposition of the American Chemical Society.

Irritating though they are, mosquitoes are much more than just pests; they're also vectors of deadly diseases that claim millions of lives every year. While some scientists race to develop and administer vaccines against these viruses, others are tackling the problem from the other end, hoping to block the bloodsuckers before they ever pierce a person's skin.

Today's most common chemical mosquito-protection measures are effective, but nonspecific. The same insecticide that takes out a mosquito can kill a bee or poison a dog or a baby. Pesticide runoff can contaminate the water supply. It also can't eliminate all the mosquitoes, and the survivors reproduce, thereby increasing their resistance to the chemicals.

In other words: There's room for improvement. So Mafra-Neto, founder of the pest management laboratory ISCA Technologies, teamed up with researchers from other universities to create something better.

First, they gathered piles of mosquitoes' favorite nectar-producing plants and analyzed the chemical makeup of each flower's fragrance. They exposed mosquitoes to individual elements of each fragrance to find out which ones got their attention, then eliminated any scent that also brought bees to the yard. The final result was an intoxicating perfume of sugars and proteins that no mosquito could refuse.

The researchers mixed this special blend with a highly concentrated, slow-release pesticide called Vectrax, which can be sprayed or spread onto plants and buildings. The pesticide solidifies in teeny droplets and will not spread to other surfaces, but it will spread in the bodies of the mosquitoes who come to taste it.

And taste it they do.

"The blend of chemicals that we use to attract mosquitoes is so powerful that they will ignore natural plant odors and attractants in order to get to our formulation," Mafra-Neto said in a statement. "From a mosquito's point of view, it's like having an irresistible chocolate shop on every corner. The product is so seductive that they will feed on it almost exclusively, even when it contains lethal doses of insecticide."

Mafra-Neto and his colleagues are currently conducting field tests in malaria-vulnerable villages of Tanzania. Their early results suggest that their product can cut mosquito populations by two-thirds in the first two weeks alone, and may be able to eliminate the pests entirely. Mafra-Neto wouldn't be sorry to see them go.

"I truly hate mosquitoes and ticks," he says. "Imagine: Maybe one day we will be able to go into our backyards or parks and not have to worry about being bothered by either of them."

No Venom, No Problem: This Spider Uses a Slingshot to Catch Prey

Courtesy of Sarah Han
Courtesy of Sarah Han

There are thousands of ways nature can kill, and spider species often come up with the most creative methods of execution. Hyptiotes cavatus, otherwise known as the triangle weaver spider, is one such example. Lacking venom, the spider manages to weaponize its silk, using it to hurl itself forward like a terrifying slingshot to trap its prey.

This unusual method was studied up close for a recent paper published in the Proceedings of the National Academy of Sciences by researchers at the University of Akron in Ohio. They say it's the only known instance of an animal using an external device—its web—for power amplification.

Hyptiotes cavatus's technique is simple. After constructing a web, the spider takes one of the main strands and breaks it in half, pulling it taut by moving backwards. Then, it anchors itself to a spot with more webbing in the rear. When the spider releases that webbing, it surges forward, propelled by the sudden release of stored energy. In the slingshot analogy, the webbing is the strap and the spider is the projectile.

This jerking motion causes the web to oscillate, tangling the spider's prey further in silk. The spider can repeat this until the web has completely immobilized its prey, a low-risk entrapment that doesn’t require the spider to get too close and risk injury from larger victims.

The triangle weaver spider doesn’t have venom, and it needs to be proactive in attacking and stifling prey. Once a potential meal lands in its web, it’s able to clear distances much more quickly using this slingshot technique than if it crawled over. In the lab, scientists clocked the spider’s acceleration at 2535 feet per second squared.

Spiders are notoriously nimble and devious. Cebrennus rechenbergi, or the flic-flac spider, can do cartwheels to spin out of danger; Myrmarachne resemble ants and even wiggle their front legs like ant antennae. It helps them avoid predators, but if they see a meal, they’ll drop the act and pounce. With H. cavatus, it now appears they’re learning to use tools, too.

[h/t Live Science]

Bad News: The Best Time of the Day to Drink Coffee Isn’t as Soon as You Wake Up

iStock.com/ThomasVogel
iStock.com/ThomasVogel

If you depend on coffee to help get you through the day, you can rest assured that you’re not the world's only caffeine fiend. Far from it. According to a 2018 survey, 64 percent of Americans said they had consumed coffee the previous day—the highest percentage seen since 2012.

While we’re collectively grinding more beans, brewing more pots, and patronizing our local coffee shops with increased frequency, we might not be maximizing the health and energy-boosting benefits of our daily cup of joe. According to Inc., an analysis of 127 scientific studies highlighted the many benefits of drinking coffee, from a longer average life span to a reduced risk for cancer, heart disease, type 2 diabetes, and Parkinson’s disease.

Sounds great, right? The only problem is that the benefits of coffee might be diminished depending on the time of day that you drink it. Essentially, science tells us that it’s best to drink coffee when your body’s cortisol levels are low. That’s because both caffeine and cortisol cause a stress response in your body, and too much stress is bad for your health for obvious reasons. In addition, it might end up making you more tired in the long run.

Cortisol, a stress hormone, is released in accordance with your circadian rhythms. This varies from person to person, but in general, someone who wakes up at 6:30 a.m. would see their cortisol levels peak in different windows, including 8 to 9 a.m., noon to 1 p.m., and 5:30 to 6:30 p.m. Someone who rises at 10 a.m. would experience cortisol spikes roughly three hours later, and ultra-early risers can expect to push this schedule three hours forward.

However, these cortisol levels start to rise as soon as you start moving in the morning, so it isn’t an ideal time to drink coffee. Neither is the afternoon, because doing so could make it more difficult to fall asleep at night. This means that people who wake up at 6:30 a.m. should drink coffee after that first cortisol window closes—roughly between 9:30 a.m. and 11:30 a.m.—if they want to benefit for a little caffeine jolt.

To put it simply: "I would say that mid-morning or early afternoon is probably the best time," certified dietitian-nutritionist Lisa Lisiewski told CNBC. "That's when your cortisol levels are at their lowest and you actually benefit from the stimulant itself."

[h/t Inc.]

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