My Science School

A keystone species is one that has an incredibly important role to play in an ecosystem. Without this species, ecosystem would be dramatically different or may even stop existing altogether. It can be any organism, from large animals to microscopic bacteria. In short, a keystone species is what holds a habitat together.

There's a call to protect the tiger because as a keystone species, this top predator plays a significant role in the health and diversity of an ecosystem.

If it disappears, the population of its prey - usually ungulates - will go up, and this will result in the decimation of vegetation, leading to a collapse of the ecosystem.

Not just animals, birds and insects, even plants can be keystone species.

Mangroves are a keystone species that firm up shorelines and reduce erosion. They provide a safe haven and feeding area for small fish among their roots, which reach down through the shallow water.

It is true that if bees go extinct, so would humans. This keystone species plays a very important role in keeping the world going.

As the most important pollinators, they are responsible for about a third of the world's total food production. Without bees, there would be food shortage, and eventual human collapse.

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When it rains, we get to see several types of creatures we may not see otherwise. In the last few weeks, especially in Tamil Nadu and Kerala, one creature has made headlines for showing up in large numbers due to the rains. But it's not really good news. Why? Come let's find out.

It is possible that you've seen the giant African snail. Especially around the time it rains. With its large, striped shell firmly on its back, you may have spotted it crossing a wet road, climbing a gate, or munching on some plant. As the name suggests, it is native to Africa, and can grow to be a large snail. And it is one of the most invasive species in the world, and is said to have landed in India several decades ago inadvertently. That they have no natural predators has played a big role in their numbers increasing. Today they are found in several States, including Tamil Nadu, Kerala, Karnataka, Andhra Pradesh, and the North-East regions too. They eat native plants and crops, altering the ecosystem and denting farmers' income. It is said that they consume even paint! They are not just pests , they are also a health hazard to humans. They can cause severe diseases as they host parasites. For this reason, they cannot be consumed by humans.

Did you know?

• Just a few months ago, a village in Kerala's Alappuzha district came up with a novel plan to get rid of this invasive species, which causes extensive damage to crops. Onam bumper tickets with a chance to win Rs. 12 crore were on offer for 10 people catching the highest number of snails.
• Recently, after witnessing the continuing menace of these snails, a group of walkers in Kerala made an announcement to buy these snails each for a rupee from residents. Apparently, within just a few days, they bought over 3,500 snails!

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Is the destruction of wetlands driving out these magnificently colorful insects?

Dragonflies are very sensitive to changed in the environment .loss of the marshes swamps and free flowing rivers they breed in are some of the risk factors.

What a new report says...

The destruction of wetlands is driving a decline of dragonflies around the world with one sixth of species of the magnificently colorful insects threatened with extinction conservationists said on Thursday.

A report from the International Union for Conservation of Nature presented the first assessment of all 6,016 dragonfly and damselfly species globally, and found that at least 16 per cent of them risked going extinct.

What's driving the extinction?

The decline is a symptom of widespread loss of the marshes, swamps and free flowing rivers they breed in driven mainly by the expansion of unsustainable agriculture and urbanization around the globe, IUCN said in the update of its "Red List of threatened species.

"By revealing the global loss of dragonflies, today's Red List update underscores the urgent need to protect the world's wetlands and the rich tapestry of life they harbor. IUCN director general Bruno Oberle said in a statement

Why are wetlands disappearing?

Globally, these ecosystems are disappearing three times faster than forests. A report published three years ago by the Ramsar Convention on Wetlands found that 35 per cent of the world's wetlands were lost between 1970 and 2015, Wetlands store carbon, protect against floods and offer habitats for one in 10 of the world's known species.

What are the warning signs?

The welfare of dragonfly species is an especially good indicator for how the wetlands are doing.

"They're very, very sensitive to changes in the environment. And so that is an early warning signal to what's happening to wetland systems around the world." Craig Hilton-Taylor, who heads IUCN's Red List unit said.

He said a lack of data meant the true number teetering on the brink of extinction could be as high as 40 per cent.

Where the problems loom large...

The situation is particularly dire in South and Southeast Asia, where more than a quarter of all dragonfly species are threatened, IUCN said.

This is largely due to the clearing of wetland and rainforest areas to make room for crops like palm oil, it explained. Pesticides, other pollutants and climate change are also growing threats. AFP

The red list

• With the latest update, the Real List now includes assessments of 142,577 species of animals and plants, including 40.084 considered to be threatened with extinction.
• This marks the first time that the number facing the highest risk has passed 40.000

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Extraordinary fungus farmers

You've probably seen pamphlets on how to grow mushrooms at home and make money. Not surprisingly, many of us wonder if it would even work out. But leafcutter ants have no such qualms - they've been master fungus farmers for centuries. If you've seen a leafcutter ant carrying a piece of leaf you assume that it's going to be food. But these leaves are taken to a garden space and used as fertilizers on a fungal farm tenderly cared for by the ants. Some ants even lick the growing fungi to spread a type of bacteria that kill other competing fungi, thus acting as a pesticide. If this isn't advanced farming, what is?

Tireless invaders

Pine processionary caterpillars bear an uncanny similarity to Genghis Khan and his army. While Genghis Khan invaded cities, these caterpillars target pine forests. Hardly 2 cms in length when they emerge out of their cocoons, these caterpillars are blessed with super strong mandibles capable of chewing pine needles soon after birth. But that's just the beginning - - as they grow, they form a single line army and invade pine trees. They march bravely even at sub-zero temperatures and destroy massive coniferous forests in a very short time!

Choosing summer retreats

Do you dream of warm, sandy beaches in the winter and snowy slopes during the sultry summers? Guess what? Locusts love such getaways, too. You may travel solo or with a small group of friends or family, but locusts do it differently. When they migrate together, what a sight it is! Referred to appropriately as the 'gregarious phase', millions of locusts fly together in a mighty swarm that intimidates creatures big and small. They can ravage crops and forests leaving behind a sorry mess. They travel for very long distances, sometimes from northwest Africa all the way to Britain or even to the Caribbean if they fancy a vacation!

A taste for electronics

What was once the home of fire ants is now owned by tawny crazy ants that invade houses with a kind of determination that is plain scary! There was a time when people hated fire ants but they are nothing when compared these ants. Fire ants built mounds in backyards and hardly bothered you unless you stepped on their home. These crazy ants have been driving people mad. This is particularly because of the interest they show in electronic equipment. They have been spotted forming bridges between electrical contact points and causing short circuits!

Simple brain, amazing focus

Dragonflies possess one amazing quality that many of us struggle with. Did you know that dragonflies can focus on a target and filter out other useless information? This process is known as 'selective attention'. Imagine how useful it would be if we could do that. If only dragonflies could write a book on focus and concentration... now that would be a bestseller!

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It would take 1.2 million mosquitoes, each sucking once, to completely drain the adult human body of blood! In the Arctic, Canadian researchers who bared their arms, legs, and torsos reported as many as 9,000 bites per minute from swarming, newly hatched mosquitoes. At that rate, an individual could lose half his blood in two hours!

A condition called hypovolemic shock sets in after you lose about 20% of your blood, and it leads to major organ failures because your heart loses the pressure necessary to circulate blood.

Another thing to consider is the amount of skin a human has for the mosquitoes to bite. An average person has about 1.75 square meters of skin. That means you'd need almost 6,300 Asian tiger mosquitoes feeding on each square centimeter of skin on your body

So unless they set up an orderly queuing system to get at your skin, there's little to no risk of having your blood drained by mosquitoes, let alone encountering a swarm of millions. But mosquitoes are not necessarily the most profilic bloodsuckers.

Credit :  Insider 

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The Asian giant hornet is the largest hornet species in the world. Native to Southeast Asia and China, they can grow up to 2 inches long. As their sting can kill people, they are also called murder hornets. Considered an invasive pest, they pose a threat to the honeybee population.

The hornets like to create their nests by digging tunnels underground or using tunnels already dug by other animals. Their main sources of food are other larger insects, tree sap, and honey. Similar to the previously mentioned wasp species, Asian giant hornets also have a large stinger that contains a potent venom. If they sting something they usually release large amounts of venom, which can be lethal to humans if it occurs several times repeatedly. This is the reason why these wasps are often called murder hornets. Several Asian giant hornets were also spotted in the Pacific Northwest of North America, which caused mass panic because of how dangerous they can be. However, there were only several sightings and it is unclear whether more will continue to appear. 

Asian Giant hornet are social wasps that build a new nest yearly underground in abandoned rodent burrows or sometimes in dead, hollow trunks or the roots of trees. Nests can house over 300 insects. 

Similar to other social bees and wasps, the Asian giant hornet colonies are made up of one queen and non-reproductive female workers. In the springtime, queens will emerge from overwintering to feed and search for a suitable nesting site. She will build a nest, forage, lay eggs, and care for the young.

Once about 40 workers have reached adulthood, they take over foraging and caring for the colony, while the queen remains in the nest and lays eggs. At the end of summer, the queen will produce reproductive males and next year's queen.

In the fall the males will leave the nest and wait outside the nest entrance for the new queen to emerge. When she emerges, males will ambush and mate with her. After mating, she will look for a place to overwinter until next spring.

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Have you heard of the "ant death spiral? It's a phenomenon wherein army ants circle round and round until they die of exhaustion. Army ants communicate using pheromones or chemical scents. When they fail to follow the scent trail left by other ants, they will break from the crowd and go around in circles.

Army ants — unlike most other ant species — are blind. They also lack permanent nesting sites. Instead of living at a single site, army ant colonies are constantly on the march en masse looking for food. As the first ant in line travels it leaves behind a pheromone trail that other ants sniff out and follow. When this system works well, it allows foraging parties lead larger groups back to food. When it doesn't work, the ants follow these pheromone trails as they flow back into each other, ending up in an endless loop that they follow to their doom. If the circle isn't broken for some reason, they will probably never escape.

Although there are more than 200 species of army ants living on both sides of the globe, genetic evidence indicates that they may all have common ancestors and have kept their evolutionary advantages and disadvantages for more than 100 million years. 

Credit : Treehugger 

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The tarantula hawk, a kind of large parasitic wasp, paralyses a tarantula spider with its sting and then lays an egg into the spider so that when the egg hatches the larva will have enough food to feed on for weeks together. Its sting is considered to be one of the most powerful insect stings on Earth.

In most cases, tarantula hawks won’t sting unless you bother them first. They’re similar to wasps in that they are incredibly bold, but it would take stepping on one or picking one up for you to receive a sting.

If you do get stung, you’ve had some bad luck, as the sting of the tarantula hawk wasp is rumored to be one of the most intense, painful stings of all insects. Because their stingers are so large, very few animals eat them, and as a result, they have few natural predators.

Luckily, the sting is not dangerous, unless you are unfortunate enough to develop an allergic reaction. The area where you are stung may remain red for up to a week, but the pain from most stings subsides within just a few minutes.

To treat the sting, make sure you wash the site with antibacterial soap and warm water. This will reduce the likelihood of an infection. You can apply a cold compress, ice, or topical cortisone or antihistamine to relieve the pain, itch, and swelling.

Credit : Rest Easy Pest Control 

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It affects them like alcohol affects humans, resulting in flying accidents. They also find it difficult to get back to their hive. Not just that, they are prohibited from entering their hive by the other bees at the hive.

After sucking on fermented limes, a drunken bee will return home to its hive (if it can make it back, that is).  Because of the honey bee’s complex and intricate way of communicating through their waggle dance, it is not very difficult for the other members of a colony to detect the drunken bee.  Once spotted, the guard bees of the hive will immediately begin their investigation and punishment.  The rules of the honey bee society are quite strict, and without much thought, the guard bees will begin to bite off the drunken bee’s legs as punishment.  One by one the bee’s legs are torn off, and the poor drunk honeybee doesn’t have much of a chance of living after her traumatic leg removal.  This sort of punishment serves as a warning to the rest of the hive to never stray away from their duties to their colony.

"On the molecular level, the brains of honey bees and humans work the same. Knowing how chronic alcohol use affects genes and proteins in the honey bee brain may help us eventually understand how alcoholism affects memory and behavior in humans, as well as the molecular basis of addiction,” stated Julie Mustard, a study co-author and a postdoctoral researcher in entomology at Ohio State University.  Mustard studied the effects that ethanol (the intoxicating agent in liquor) had on honeybee behavior.  This study could eventually prove the long term and social effects that alcohol has on human behavior.

Credit :  Ripleys 

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Only female bees can sting. A bee's sting is like a sharp thorn at the end of its abdomen. If the thorn is left in your flesh, the bee cannot sting again!

When a honey bee stings you, its sharp, barbed stinger pierces the skin. This stinger injects a venom called apitoxin. In most cases, the stinger gets stuck in the victim’s skin and tears loose from the bee. In most cases, this is a massive injury to the honey bee. Other parts of its body rip off with the stinger, killing the bee. The stinger then continues to pump venom into the victim for up to 10 minutes or until it is removed.

Honey bees are the only bee species that die after stinging. However, honey bees sometimes survive after stinging if the victim’s skin is thin and doesn’t hold the barbed end of the stinger. This doesn’t happen often, though, because honey bee stingers are designed to stick in the skin of the victim to release as much venom as possible.

Bee stings can be quite painful. For some people, though, they can actually be deadly. Some people are allergic to the venom in bee stings. For these people, a sting can trigger a dangerous allergic reaction. If you‘re outside with a person who’s allergic to bees, make sure you know where to find help if they are stung.

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Many pond insects seem to walk on water. They do so because of the surface tension. The pond skater's legs press into a kind of elastic skin on the surface of the water but don't go through!

Water acts different at the surface. Water molecules are attracted to each other and like to stay together, especially on the surface where there is only air above. The attraction between water molecules creates tension and a very delicate membrane. Water striders walk on this membrane.

Water striders are about a half-inch long with a thin body and three sets of legs. The water strider's secret is its legs. The legs have tiny hairs that repel water and capture air. By repelling water, the tiny water striders stand on the water’s surface and the captured airs allows them to float and move easily.

The water strider's shorter front legs are used for catching and holding onto food. Water striders eat insects and larvae on the surface of water, such as mosquitoes and fallen dragonflies.

Credit : National Wildlife Federation 

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It is fossilised resin from conifer trees that seeped out millions of years ago. Often insects were trapped inside. It lies buried until it is washed up on the seashore.

Amber occurs as irregular nodules, rods, or droplike shapes in all shades of yellow with nuances of orange, brown, and, rarely, red. Milky-white opaque varieties are called bone amber. The turbidity of some amber is caused by inclusions of many minute air bubbles. Many hundreds of species of fossil insects and plants are found as inclusions. Deeply coloured translucent to transparent amber is prized as gem material.

Modern investigative techniques are directed toward isolating and identifying as many as possible of the individual resin components and, ultimately, to establishing a genetic relationship between fossil resins and modern resin-producing trees. By means of infrared spectroscopy, Mexican (Chiapas) amber has been shown to be related to a modern leguminous tree, Hymenaea. Though in the past amber was believed to be completely amorphous, subsequent X-ray diffraction studies have revealed crystalline components in some fossil resins.

Ornamental carved objects, beads, rosaries, cigarette holders, and pipe mouthpieces are made from amber. Amberoid, or “pressed amber,” is produced by fusing together small pieces of amber under pressure. Parallel bands, or flow structure, in amberoid help to distinguish it from natural amber. Despite the introduction of numerous synthetic substitutes, the beauty of the real material has remained unexcelled.

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To begin, insects don't have a vertebral column (backbone) like people have and therefore are considered to be a type of invertebrate animal. Instead of a backbone, insects have a hard exterior body covering, called an exoskeleton. Insects are arthropods: invertebrate animals that have an exoskeleton, a segmented body, and jointed appendages. Arthropods are members of the taxonomic phylum Arthropoda, which includes insects, arachnids, and crustaceans. Insects represent about 90 percent of all life forms on earth. More than one million insect species have been identified throughout the world, and some entomologists (scientists that study insects) estimate there may be as many as 10 million species. These species are divided into 32 groups called orders, and beetles make up the largest group. No one knows exactly how many insects are found within Everglades National Park. Entomologists have prepared lists of some insect groups, such as bees, ants, and butterflies, but no park-wide inventory has been carried out yet. 

Insects have six legs and two antennae, and their body is made up of three main regions: head, thorax, and abdomen. They have an exoskeleton that contains sense organs for sensing light, sound, temperature, wind pressure, and smell. Insects typically have four separate life stages: egg, larvae or nymph, pupa, and adult. Insects are cold blooded and do not have lungs, but many insects can fly and most have compound eyes. Insects are incredibly adaptable creatures and have evolved to live successfully in most environments on earth, including deserts and even the Antarctic. The only place where insects are not commonly found is in the oceans. Insects pollinate flowers and crops and produce honey, wax, silk, and other products. However, some species that bite, sting, destroy crops, and carry disease may be considered pests to people and animals.

Credit : National Park Service 

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The number “1 million billion” may sound made up or incalculable, but you’ll reach it trying to count all the ants on the planet. We share the Earth with an estimated 1 quadrillion ants spread out over more than 12,000 ant species. That’s 1,000,000,000,000,000 of these insects. This outnumbers all other living species on Earth, excluding bacteria. The next time you’re feeling stressed about the sight of a few dozen ants in your home, take a breath and be thankful that all the ants on the planet aren’t working together.

Enthusiastically social insects, ants typically live in structured nest communities that may be located underground, in ground-level mounds, or in trees. Carpenter ants nest in wood and can be destructive to buildings. Some species, such as army ants, defy the norm and do not have permanent homes, instead seeking out food for their enormous colonies during periods of migration.

One Amazon species (Allomerus decemarticulatus) cooperatively builds extensive traps from plant fiber. These traps have many holes and, when an insect steps on one, hundreds of ants inside use the openings to seize it with their jaws.

Another species, the yellow crazy ant (Anoplolepis gracilipes), is capable of forming so-called supercolonies that house multiple queens. On Australia’s Christmas Island, the accidental introduction of yellow crazy ants in the early 20th century has led to a destructive infestation. The ants are a significant threat to the island’s endemic population of red crabs, which are displaced by the ants from their burrows or killed as they pass through ant nest sites during the crabs' large-scale annual migration from the forest to the coast.

Credit : National Geographic

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Cockroaches are infamous for their tenacity, and are often cited as the most likely survivors of a nuclear war. Some even claim that they can live without their heads. It turns out that these armchair exterminators (and their professional brethren) are right. Headless roaches are capable of living for weeks.

Cockroaches do in fact have brains. And they use them. It’s just that cockroaches don’t really need them that much.

In addition to brains, they have nerve tissues that control reflexes throughout their bodies, and these are distributed within each body segment. If a cockroach loses its head and brain, the nerve tissues (known as nerve tissue agglomerations) continue doing their job, providing the strange headless creature a fairly normal life. It can stand, react to touch, and move around. Cockroaches do in fact have brains. And they use them. It’s just that cockroaches don’t really need them that much.

In addition to brains, they have nerve tissues that control reflexes throughout their bodies, and these are distributed within each body segment. If a cockroach loses its head and brain, the nerve tissues (known as nerve tissue agglomerations) continue doing their job, providing the strange headless creature a fairly normal life. It can stand, react to touch, and move around.

A headless cockroach isn’t going to die from bleeding and it’s not going to die from being unable to breathe. It’s also not going to die from the relatively minor event (for it) of losing its brain.

But it is going to die from being unable to eat. And well before that, it’s going to die from thirst. A headless cockroach has no mouth to drink with and will be dead from dehydration in less than a week.

Credit : Cockroach Facts 

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