Category Zology

Are daddy long-legs the most poisonous spiders in the world?

It turns out that the notion is false on both counts. But a little clarification is needed.

According to entomologists at the University of California, Riverside, the term “daddy longlegs” is commonly used to refer to two distinct types of creatures: opilionids arachnids with pill-shape bodies and eight long legs that are actually not spiders, and pholcids, which have long legs and small bodies, and thus resemble opilionids, but which are true spiders.

Pholcids, or daddy long-legs spiders, are venomous predators, and although they never naturally bite people, their fangs are similar in structure to those of brown recluse spiders, and therefore can theoretically penetrate skin. For these reasons, “This is most probably the animal to which people refer when they tell the tale,” the entomologists assert.

But is pholcids’ venom extremely poisonous? Surprisingly, because they almost never bite, scientists have never bothered to conduct research to determine their venom’s toxicity to humans . In 2004, the Discovery Channel show “Mythbusters” stepped in to fill this knowledge void. The team set out to coax a daddy longlegs spider into biting the arm of the show’s co-host, Adam Savage.

 

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Is the deadly Sydney funnel-web spider found in Victoria?

Sydney funnelweb spiders are not found in Victoria.

The two Victorian funnelweb spider species are relatives of the Sydney funnelweb spider. 

Funnelweb spiders are found around the east coast and the highlands of Australia (from Queensland to Tasmania) and small regions of South Australia. Most are found on the ground where they build burrows in moist, cool, sheltered areas, but some are tree-dwelling. They are regarded to be the most notorious of the Australian spiders due to their highly toxic and fast-acting venom. However, out of at least 40 species, only the male Sydney funnelweb spiders have been responsible for recorded deaths

Funnelweb spiders have a shiny black head and legs, and black to brown abdomen covered in fine hairs. The females are slightly larger (35 mm) than the males (30 mm).

The female produces a pillow-shaped silk egg sac, which she defends vigorously if disturbed. The spiderlings hatch about 3 weeks later, and stay with the mother for a few months. Funnelwebs reach maturity in about 2–4 years. The females live for 10 or more years, whereas the males die 6–9 months after maturity.

 

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Where did the barking spider get its name?

The barking spider, sometimes called the whistling spider, is an Australian farantula. When disturbed, they produced a sound by rubbing their palps over their fangs. The largest are found in Queensland, and some have been found in north-west Victoria.

Barking Spiders produce their barking sound by rubbing rows of spines on their palaps against spines on their lower jaw. This noise is used to deter predators.

The deserts are prone to flash flooding and Barking Spiders live in burrows with leaky rooves. The hairs on their body trap air bubbles during flash floods and the air pocket prevents them from drowning.

Barking Spiders have brush feet with claw tufts and a film of oil produced from a special gland which gives them a suction cup ability to climb smooth vertical surfaces.

 

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When was the red-back spider anti-venom discovered?

The red-back spider anti-venom was discovered in 1956. Since the development of the anti-venom for red-back spiders, latrodectus hasselti, there have virtually been no confirmed deaths from red-back bites. If you are bitten by a red-back spider, serious illness does not develop for at least three hours after the bite, giving you enough time to get to a doctor or hospital. Red-back spider bites cause intense local pain and localized sweating which may be followed by other symptoms including muscular weakness and spasm, loss of coordination, nausea and dizziness.

Compared with the placebo group, the antivenom had very little effect, but it caused allergic reactions in 4% of those receiving it (remember the risk of this comes from the fact that we’re using antibodies made by horses as the basis of the antivenom).

Based on this, Isbister says the treatment of redback spider bites should be re-evaluated. But other toxinologists quoted in the news reports highlighted that past studies have indicated the antivenom was effective.

 

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What is the scientific study of ants?

Myrmecology is the scientific study of ants and is a branch of entomology (the study of insects). There are more than 12,500 described species in the ant family that have been classified out of an estimated total of 22,000.  Ants are found everywhere in the world including areas that are temperate and tropical.  Most of the described and unknown species are located in the rainforests, however, due to the destruction of those forests, most of them will probably never be categorized.  The only land mass lacking ants are Antartica and a possibly a few remote or inhospitable islands.

Ants often are studied by engineers for biomimicry and by network engineers for more efficient networking. It is not known clearly how ants manage to avoid congestions and how they optimize their movements to move in most efficient ways without a central authority that would send out orders. There already have been many applications in structure design and networking that have been developed from studying ants, but the efficiency of human-created systems is still not close to the efficiency of ant colonies. Furthermore, there are efforts to use ant algorithms and the behavioral strategies of ants in modern management.

 

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Why are insects indispensable?

Scientists have sounded alarm over the rapid decline in insect population. In a series of papers published in the latest Proceedings of the National Academy of Sciences, scientists have pointed out how human activities are posing multi-dimensional risks to the insect population. The threats include deforestation, climate change, invasive species, pesticide use, habitat loss, pollution, forest fire, urbanisation and light pollution. On an average, the decline in insect abundance is estimated to be around 1-2% per year or 10-20% per decade. These losses are seen in all continents.

Why is this a cause for concern?

Insects are useful to humankind and the environment in a number of ways. They pollinate crops we rely on for food, keep pests in check, and recycle nutrients in the soil. They have been doing many other vital ecological processes for millions of years that it would be hard to imagine a world without them. In this Eco-logical, let’s take a look at some of these beneficial insects.

Bees

Bees pollinate a third of everything we consume. These include crops, fruits, vegetables, nuts, coffee, tea, and plants such as sunflowers that are turned into oil. Crops grown as fodder for livestock are pollinated by bees. Bees play a crucial role in sustaining biodiversity. Many flowering plants depend on bees for pollination. Without bees, even birds and animals that depend on plants for food will suffer.

Honeybees, a bee species, have the distinction of being the only insect that produces a food consumed by humans. Humans also use beewax, secreted by the insects to build the honeycombs, to make candles and lubricants.

Ladybugs

Ladybugs help humans by keeping a check on pests that destroy crops. Ladybugs have a voracious appetite. They consume plant-eating insects such as aphids, spider mites and mealybugs and in doing so they help protect crops.

Ladybugs lay hundreds of eggs in the colonies of pests, and when the eggs hatch, the larvae begin to feed on the pest insects. Farmers use ladybugs for biological pest managements. This way, the bugs help reduce the use of harmful pesticides.

Praying mantises, green lacewings and dragonflies too help humans in a similar fashion. These insect eat moths, mosquitoes, roaches, flies and many other insects considered pests by humans.

Dung beetles

Have you seen a dung beetle? They have a dark, round body with hard, protective covers and they are mighty recyclers. As the name suggests, their diet is dung – yes, animal and human faeces. They actually feed on the food that pass through an animal’s body undigested. While larvae eat the solid poop, the adult beetles generally suck up the nutritious moisture from the dung. They store their food underground. By burying the dung, the beetles loosen and nourish the soil and help control fly populations. If not for such decomposers, the world would be a barren, smelly landscape filled with flies.

Other decomposer insects such as carrion beetle play a significant role of eliminating dead or rotten bodies of plant or animals from the environment by feeding on them. Some of the other carrion feeders include ants, mites, wasps and fly larvae (maggots).

Butterflies and moths

Besides being a vital element of the food chain- as pollinators and as prey for birds, bats and other insectivorous animals – butterflies and moths are important to humans for their aesthetic value. Butterflies are among the most appealing creatures in Nature, with colours and ornate patterns that are enjoyed by humans. They inspire art and literature. In some cultures, butterflies are portrayed as symbols of souls, freedom, love and peace. Other insects groups represented in art include bees, beetles, grasshoppers, and dragonflies.

Insect as food

Many species of insects are known worldwide to be part of human diet. Some important groups include grasshoppers, caterpillars, beetle grubs, winged termites, bees, worms, ant brood, cicadas, and a variety of aquatic insects. Scientific research has shown that edible insects are a very rich source of protein and other nutrients. Eating insects can, in fact, help fight hunger and food insecurity.

 

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