If we took humans off the Earth, it would probably increase its life by a million years. If we took spiders off the Earth, we would all die in less than 5 years. That is how important arachnids are.
Spiders are the dominant terrestrial predators on the planet. There are more individual spiders, and spider species, than in any other group of predators. (Only 4% of all animal species on the planet are vertebrates, and mammals make up less than four tenths of one percent.) On land, the key players in maintaining habitats and structuring communities are plants and arthropods. Arthropods are members of the invertebrate group, which includes insects, crustaceans, and spiders. And spiders are far and away the Top Arthropods.
There are 36,000 known varieties and one acre of meadow in late summer has been estimated to contain more than 2 million spiders. Its safe to assume that wetlands and undisturbed forest contain many more.
They eat a lot. Assuming an average consumption of 0.1 gram of prey per spider per day, the spiders in one hectare of forest would consume 47,500 kilograms of prey per year–which is equal to 47.5 metric tons of insects!
Because they structure insect communities wherever they occur, spiders play a vital role in the terrestrial food chain. Without all those hungry, carnivorous spiders, insect populations would explode, food crops would be decimated, ecological balances would be ravaged, and humans would probably starve within a matter of months if they hadnt already died from insect borne diseases. No spider, incidentally, has been found to transmit disease.
That is how important they are.
A less important thing (in my view) is that they spin silk and that they each have a unique form of venom. Spiders use silk for many things – egg cases, nurseries for young spiders, tunnels for burrows and trapdoors to tunnels. But the main use is to make webs or orbs to catch prey, and then to wrap captured prey before killing it. After killing or paralysing prey with venom, the spider crushes its victim between lobes and jaws, sucks out body juices, and filters out solid particles.
Spider silk is stronger than steel, more elastic than nylon; to break under its own weight a strand would have to be over 40 miles long. Its thin enough to be workable, almost light enough to float, and can withstand low temperatures. The ancient Greeks used spider silk very effectively to staunch bleeding wounds, as have soldiers in the Vietnam War and other modern conflicts. The silk is so fine that it actually traps the blood platelets. New Guinean natives use spider webs for fishing nets. Up until World War II spider silk was used for the cross hairs in gun sights and optical instruments.
Spiders cannot be farmed since they eat each other in close proximity. But researchers have long dreamed of applications for this unique material: for example, for use in bullet-proof vests (this silk is stronger than Kevlar which in turn is stronger than steel) surgical thread or replacement ligaments inside the body; as parachute cords; and as tethers for planes on aircraft carriers. Scientists have been extensively researching the molecular structure of spider silk in the hopes of replicating it synthetically.
Few spiders will bite, even when coaxed, and the bites of most of those large enough to penetrate the skin produce no harm at all. Despite horror films, a tarantula bite is hardly worse than a bee or wasp sting, unless the victim has a particular allergy. In fact, some ants, bees, and wasps are far more dangerous. Of the thousands found worldwide, only a dozen or so can be dangerous to man.
Spiders produce an impressive array of very effective venom. Venom serves two purposes–to paralyze the prey and to digest it–and can be broadly categorized into two classes; neurotoxic, affecting nerve cells, and cytotoxic, affecting tissues. Researchers have isolated several interesting components of this chemical cocktail, and are using them as medicines: They can treat certain neurological and mental disorders. Research groups have isolated components from the venom which may help reduce brain damage following strokes. As insecticides: The venom of each species has evolved over millions of years to have a particular biochemical effect in ways that chemists would never have thought of on their own, and which set them off on completely novel lines of research. Once a compound has been isolated, it can often be synthesized and produced in quantity. Researchers have already screened the venom of thousands of spiders species for components with promising biochemical properties.
Research is being done into putting spiders to work in on the farm, to control insect pests. Spiders control pests in rice paddies, vineyards, apple orchards in Israel and rice fields in China. Their latest success has been in Hubei Province, China. Cotton is the chief crop and pesticides have long been used to control the boll weevil. But no insecticides work on the bollweevil and not only have cotton growing areas become hazard zones of pesticide, the world crop continues to fall. The University of Hubei zeroed in on the most appropriate spider species to control bollweevils. Then they figured out how to feed and shelter them during the off season (bunches of spider-friendly grass are placed in shallow holes and in trees). The spiders stay in these grassy areas and when the cotton blooms, they come out and eat the pests. Cotton farmers throughout Hubei have saved money on pesticides and reduced chemical use by 80%; they have fewer health problems; and crop yields have increased.
Arachnophobia is widespread and as with most fears, the greatest cause does not understand them. Actually spiders are fascinating. But I will leave their wondrous cunning and mimicry, their mating and architecture, their parenting and hunting for another piece. I like spiders in my own house. They keep the mosquitoes and flies under control. The morning webs in the garden, sparkling with dew are beautiful. But then I like every single natural creation on this earth.
I dont think spiders are a problem in anyones house but for those that need to fix it even if it isnt broke here are pointers.
Spiders may enter houses and other structures through cracks and other openings. They also may be carried in on items like plants or boxes. Individual spiders can also be removed from indoor areas by placing a jar over them and slipping a piece of paper under the jar that then seals off the opening of the jar when it is lifted up. Then take the spider outside and put it in a safe place where it can do its good work.
To prevent spiders from coming indoors, seal cracks in the foundation and other parts of the structure and gaps around windows and doors. Good screening not only will keep out many spiders but also will discourage them by keeping out insects that they must have for food. Outdoor lighting attracts insects, which in turn attracts spiders. If possible, keep lighting fixtures off structures and away from windows and doorways. Sweep webs and spiders off buildings regularly.
Open water on the property provides a breeding source for many insects, including mosquitoes and midges, which in turn attracts spiders. Homes built right on a lake are prime candidates for spider infestations. Houses next to open fields are also common sites of spider infestations. In these areas winds carry spider lings into the area, where they end up on the sides of the house. Once spiders build up outdoors on structures, they naturally filter indoors through cracks and crevices around windows, doors.
Avoid using chemical fertilizers on your property. Excess nitrogen attracts many insects, such as aphids. The stress attracts insects, which in turn attracts the spiders. Once spiders over flow on your property, they will naturally over flow into your home. Broad spectrum pesticides may kill off beneficial insects and, without the good guys to control them pest populations may explode. Pesticide applications in time also kill off beneficial bacteria which in turn causes stress in the plants. All stressed plants attract insects. Indoor plants that are stressed will especially attract insects, and spiders.
In any case if you use some neem oil, peppermint oil, tea tree oil or citronella oil in your mop you wont really get any insects in your house.
The best solution is of course to stop being scared of them and learn to live with them. They are certainly more important than we are.
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