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[中一] Wholesale NHL Jerseys 2020 pyhmy5y3

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發表於 2018-6-26 16:42:20 | 只看該作者 回帖獎勵 |倒序瀏覽 |閱讀模式
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Did you know that the common housefly that is known to flutter in and around, like the mosquito, has the potential of carrying some very serious diseases which can be detrimental to mankind?Houseflies are in fact one of the most widely distributed disease-carrying insects that are often regarded as pests.A close-up of a houseflyThis common fly originated on the steppes of central Asia, but now occurs on all inhabited continents, in all climates from tropical to temperate, and in a variety of environments ranging from rural to urban. It is commonly associated with animal faeces, but has adapted well to feeding on garbage, so it is abundant almost anywhere people live.With a tendency to aggregate they are very difficult to dispel and are capable of carrying over 100 pathogens such as typhoid, cholera, salmonella, bacillary dysentery, tuberculosis, anthrax, ophthalmia and parasitic worms.It must, however, be noted that flies in poorer and lower-hygienic areas usually carry more pathogens.In fact,Wholesale Jerseys, according to reports, there are some strains of these flies that have become immune to most common insecticides.This insect species is said to feed primarily on liquid or semi-liquid substances beside solid material which has been softened by saliva or vomit.Researchers have been able to determine that because of their high intake of food, houseflies deposit faeces constantly, which is one of the factors that make the insect a very dangerous and heinous carrier of pathogens.Although domestic flies, as their name suggests, are usually confined to the human habitations, they can fly for several miles from the breeding place.However, they are active only in daytime and rest at nights in the corners of rooms, ceilings and other secluded areas.Adult houseflies can reach lengths ranging between six and nine millimetres (mm) long and are outfitted with a grey thorax with four longitudinal dark lines on the back.The underside of their abdomen is yellow and their whole body is covered with hair.Females are slightly larger than males and have a much larger space between their red compound eyes.And like most two-winged insects, houseflies have only one pair of wings.Each female fly can lay more than 500 eggs in several batches of about 75 to 150.The eggs are white and are approximately 1.2 mm in length.Within a day larvae can hatch from the eggs and it is said that they live and feed in organic material such as garbage or faeces.They are pale-whitish measuring three to nine mm long and are thinner at the mouth end and have no legs.After a period of development, the larvae crawl to a dry cool place and transform into pupae and take on a reddish or brown colour, measuring about eight mm long. Further development eventually leads to an adult fly emerging from the pupae. The entire cycle is known as complete metamorphosis.Having emerged from the pupae the fly will cease to grow hence small flies are not young flies but were rather deprived sufficient food during the larval stage.Some 36 hours after emerging from the pupa the female is receptive for mating.Normally the female mates only once and stores the sperm to use it repeatedly for laying several sets of eggs.The average lifespan of an adult housefly is approximately 15 to 25 days.  It is said that because they can complete their lifecycle in as little as seven to 10 days, flies typically live between 22 and 25 days from egg to death.And since houseflies can only consume liquid foods they spit out saliva on solid foods to predigest it and then suck it back inside.They also regurgitate partly digested matter and pass it again to the abdomen.These flies are able to walk on vertical planes and can even hang upside-down from ceilings. This, according to researchers, is accomplished with the surface tension of liquids secreted by glands near their feet.When they are not flying, these flies continually preen themselves, cleaning their eyes with their forelegs and dusting off their legs by rubbing them together, a habit they practice since their taste and smell receptors are located on the hair of their legs. (Information Sourced from the Wikepedia Free Online Encyclopaedia).
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