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Termite Ingenuity
Termites,social incts which live in colonies that,in some species,contain 2 million individuals or more,are often incorrectly referred to as white ants.But they are certainly not ants.Termites,unlike ants,have gradual metarnorphosis with only three life stage:egg,nymph,and adult.Ants and the other social members of their order,certain bees and wasps,have complete metarnorphosis in four life stages;egg,larva,pupa,and adult.The worker and soldier castes of social ants,bees,and wasps consist of only females,all daughters of a single queen that mated soon after she matured and thereafter never mated again.The worker and soldier castes of termites consist of both males and females,and the queen lives permanently with a male consort.
Since termites are small and soft-bodied,they easily become desiccated and must live in moist places with a high relative humidity.They do best when the relative humidity in their nest is above 96 percent and the temperature is fairly high,an optimum of about 79°F for temperate zone species and about 86°F for tropical species.Subterranean termites,the destructive species that occurs commonly througho
ut the eastern United States,attain the conditions by nesting in moist soil that is in contact with wood,their only food.The surrounding soil keeps the nest moist and tends to keep the temperature at a more or less favorable level.When it is cold in winter,subterranean termites move to burrows below the frost line.
Some tropical termites are more ingenious engineers,constructing huge above-ground nests with built-in“air conditioning”that keeps the nest moist,at a constant temperature,and well supplied with oxygen.Among the most architecturally advanced of the termites is an African species,Macroternes natalensis.Renowned Swiss entomologist Martin Luscher described the mounds of this fungus-growing species as being as much as 16 feet tall,16 feet in diameter at their ba,and with a cement-like wall of soil mixed with termite saliva that is from 16 to 23 inches thick.The thick and den wall of the mound insulates the interior microclimate from the variations in humidity and temperature of the outside atmosphere.Several narrow and relatively thin-walled ridges on the outside of the mound extend from near its ba almost to its top.
According to luscher,a medium-sized nest of Macrotermes has a population of about 2 million individuals.The metabolism of so many termites and of the fungus that they grow in their gardens as food helps keep the interior of the nest warm and supplies some moisture to the air in the nest.The t
ermites saturate the atmosphere of the nest,bringing it to about 100 percent relative humidity,
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But how is this well-insulated nest ventilated?Its many occupants require over 250 quarts of oxygen(more than 1,200 quarts of aire)per day.How can so much oxygen diffu through the thick walls of the mound?Even the pores in the wall are filled with water,which almost stops the diffusion of gas.The answer lies in the construction of the nest.The interior consists of a large central core in which the fungus is grown,below it is“cellar”of empty space,above it is an“attic”of empty space,and within the ridges on the outer wall of the nest,there are many small tunnels that connect the cellar and the attic.The warm air in the fungus gardens ris through the nest up to the attic.From the attic,the air pass into the tunnels in the ridges and flows back down to the cellar.Gas,mainly oxygen coming in and carbon dioxide going out,easily diffu into or out of the ridges,since their walls are thin and their surface area is large becau they protrude far our from the wall of the mound.Thus air that flows down into the cellar through the ridges is relatively rich in oxygen,and has lost much of its carbon dioxide.It supplies the nest’s inhabitants with fresh oxygen as it ris through the fungus-growing area back up to the attic.
Passage 1
Termites,social incts which live in colonies that,in some species,contain 2 million individuals or more,are often incorrectly referred to as white ants.But they are certainly not ants.Termites,unlike ants,have gradual metarnorphosis with only three life stage:egg,nymph,and adult.Ants and the other social members of their order,certain bees and wasps,have complete metarnorphosis in four life stages;egg,larva,pupa,and adult.The worker and soldier castes of social ants,bees,and wasps consist of only females,all daughters of a single queen that mated soon after she matured and thereafter never mated again.The worker and soldier castes of termites consist of both males and females,and the queen lives permanently with a male consort.
1.The author mentions“white ants”in the beginning of the passage in order to
A.correct a common misunderstanding about termites’处女的特征
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B.introduce the idea that termites only take the form of ants during certain life stages
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C.argue that not all white ants are social incts导卫
D.Illustrate the large variety of inct species that live in colonies
2.According to paragraph 1,which of the following is true about termites?教师培训管理平台
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