ielts8-test4-R3

collecting ant specimens/ˈspes.ə.mɪn/

Collecting ants can be as simple as picking up stray/streɪ/ ones and placing them in a glass jar, or as complicated as completing an exhaustive survey of all species present in an area and estimating their relative abundances估计其相对丰度. The exact method used will depend on the final purpose of the collections. For taxonomy or classification, long series, from a single nest, which contain all castes (workers, including majors and minors, and, if present, queens and males) are desirable, to allow the determination确定 of variation变种 within species. For ecological/ˌiː.kəˈlɒdʒ.ɪ.kəl/ studies, the most important factor is collecting identifiable samples of as many of the different species present as possible. Unfortunately, these methods are not always compatible. The taxonomist sometimes overlooks whole species in favour of those groups群体 currently under study, while the ecologist often collects only a limited number of specimens of each species, thus reducing their value for taxonomic investigations.

  1. compatible adjective UK /kəmˈpæt.ə.bəl/ US /kəmˈpæt̬.ə.bəl/ C1 able to exist, live together, or work successfully with something or someone else可共存的;协调的;兼容的
    It was when we started living together that we found we just weren’t compatible.
    等到开始生活在一起时,才发现我们根本合不来。This software may not be compatible with older operating systems.该软件可能与较老的操作系统不兼容。Such policies are not compatible with democratic government.此类政策与民主政体格格不入。Are their two blood groups compatible (= can blood from one person be given to the other person)?他俩的血型相容吗?
  2. identify 识别,认出;确定,发现 —- identifiable adjective UK /aɪˈden.tɪ.faɪ.ə.bəl/ US /aɪˌden.t̬əˈfaɪ.ə.bəl/  able to be recognized能被识别的
    In her bright yellow coat, she was easily identifiable in the crowd.她穿着鲜艳的黄色外套,在人群中很容易辨认。
  3. ecological adjective UK /ˌiː.kəˈlɒdʒ.ɪ.kəl/ US /ˌiː.kəˈlɑː.dʒɪ.kəl/
    B2 relating to ecology or the environment生态的;生态学的;环保的
    The destruction of the rain forests is an ecological disaster.雨林遭破坏是一种生态灾难。
  4. variation noun UK /ˌveə.riˈeɪ.ʃən/ US /ˌver.iˈeɪ.ʃən/
    variation noun (CHANGE) B2 [ C or U ] a change in amount or level变化;变动
    Unemployment rates among white-collar workers show much less regional variation than corresponding rates among blue-collar workers.白领工作者的失业率与蓝领工人相比,地区性差异要小得多。The medical tests showed some variation in the baby’s heart rate. 医学检验表明婴儿的心率有些不齐。global temperature variations over the last 140 years过去140年间全球气温的变化
    variation noun (DIFFERENCE)C2 [ C ] something that is slightly different from the usual form or arrangement变种,变体;变化了的东西
    There are wide variations in the way pensioners have benefited from the system.
    养老金领取者从这个体制中受益的情况有很大差别。The films she makes are all variations on the same theme.她拍的电影围绕的都是同一主题。
  5. pension 养老金—– pensioners 养老金领取者.
  6. caste noun [ C or U ] UK /kɑːst/ US /kæst/  a system of dividing Hindu society into classes, or any of these classes(印度社会的)种姓制度,种姓
    the caste system 种姓制度
  7. nest noun [ C ] UK /nest/ US /nest/ (HOME)   C2 a structure built by birds or insects to leave their eggs in to develop, and by some other animals to give birth or live in(鸟类或昆虫的)窝,巢;某些动物的穴
    a bird’s nest鸟巢.  a wasps’/hornets’ nest黄蜂/马蜂窝.    a rat’s nest鼠穴.
  8. specimen noun [ C ] UK /ˈspes.ə.mɪn/ US /ˈspes.ə.mɪn/
    C2 something shown or examined as an example; a typical example样品;标本;样本。     He has a collection of rare insect specimens.他收集了很多稀有昆虫的标本。Museums will pay large amounts of money for good dinosaur fossil specimens.博物馆愿意出大价钱购买完好的恐龙化石标本。Astronauts brought back specimens of moon rock.宇航员带回了月球岩石的样本。
    a small amount of blood or urine used for testing(用于化验的)血样,尿样
    They took blood and urine specimens for analysis.他们采集血样和尿样作分析。
  9. stray verb [ I ] UK /streɪ/ US /streɪ/ to travel along a route that was not originally intended, or to move outside a limited area偏离原路;越过限定区域
    A herd of cattle had strayed into the road.一群牛偏了道儿,上了公路。
    They got lost when they strayed too far from the path.他们偏离小路太远,迷了路。
    The ship strayed off course during the storm.船在暴风雨中偏离了航道。
    to start thinking or talking about a different subject from the one you should be giving attention to走神;偏离主题
    I think we’ve strayed too far from our original plan.我想我们偏离原来的计划太远了。
    Sorry – I’ve strayed from the subject.对不起——我跑题了。
    stray noun [ C ] UK /streɪ/ US /streɪ/a pet that no longer has a home or cannot find its home流浪宠物;走失的宠物
    a stray dog流浪狗。”Who owns that cat?” “I don’t know. I think it must be a stray.””那只猫是谁的?””我不知道。我觉得它肯定是只流浪猫。”
    stray adjective [ before noun ] UK /streɪ/ US /streɪ/
    Stray things have moved apart from similar things and are not in their expected or intended place.零星的,零落的
    There are still a few stray spots of paint on the window pane.窗玻璃上还有零星的几个油漆点儿。Several journalists have been killed or injured by stray bullets while reporting on the civil war. 有几位记者在报道内战时因被流弹打中而丧命或负伤。
  10. abundance noun [ S or U ] UK /əˈbʌn.dəns/ US /əˈbʌn.dəns/ formal, the situation in which there is more than enough of something:There was an abundance of food at the wedding. We had wine in abundance.
  11. taxonomy noun [ C or U ] UK /tækˈsɒn.ə.mi/ US /tækˈsɑː.nə.mi/ specialized
    分类学;生物分类学; taxonomy 分类学—- taxonomists 分类学家—– taxonomic adj.

To collect as wide a range of species as possible, several methods must be used. These include hand collecting, using baits to attract the ants, ground litter sampling, and the use of pitfall traps. Hand collecting consists of searching for ants everywhere they are likely to occur. This includes on the ground, under rocks, logs or other objects on the ground, in rotten wood on the ground or on trees, in vegetation, on tree trunks and under bark. When possible, collections should be made from nests or foraging columns and at least 20 to 25 individuals collected. This will ensure that all individuals are of the same species, and so increase their value for detailed studies. Since some species are largely nocturnal. collecting should not be confined to daytime. Specimens are collected using an aspirator (often called a poorer), forceps, a fine, moistened paint brush, or fingers. if the ants are known not to sting. Individual insects are placed in plastic or glass tubes (1.5-3.0 ml capacity for small ants, 5-8 ml for larger ants) containing 75% to 95% ethanol. Plastic tubes with secure tops are better than glass because they are lighter, and do not break as easily if mishandled.

Baits can be used to attract and concentrate foragers. This often increases the number of individuals collected and attracts species that are otherwise elusive. Sugars and meats or oils will attract different species and a range should be utilised. These baits can be placed either on the ground or on the trunks of trees or large shrubs. When placed on the ground, baits should be situated on small paper cards or other flat, light-coloured surfaces, or in test-tubes or vials. This makes it easier to spot ants and to capture them before they can escape into the surrounding leaf litter.

Many ants are small and forage primarily in the layer of leaves and other debris on the ground. Collecting these species by hand can be difficult. One of the most successful ways to collect them is to gather the leaf litter in which they are foraging and extract the ants from it. This is most commonly done by placing leaf litter on a screen over a large funnel, often under some heat. As the leaf litter dries from above, ants (and other animals) move downward and eventually fall out the bottom and are collected in alcohol placed below the funnel. This method works especially well in rainforests and marshy areas. A method of improving the catch when using a funnel is to sift the leaf litter through a coarse screen before placing it above the funnel. This will concentrate the litter and remove larger leaves and twigs. It will also allow more litter to be sampled when using a limited number of funnels.

The pitfall trap is another commonly used tool for collecting ants. A pitfall trap can be any small container placed on the ground with the top level with the surrounding surface and filled with a preservative. Ants are collected when they fall into the trap while foraging. The diameter of the traps can vary from about 18 mm to 10 cm and the number used can vary from a few to several hundred. The size of the traps used is influenced largely by personal preference (although larger sizes are generally better), while the number will be determined by the study being undertaken. The preservative used is usually ethylene glycol or propylene glycol, as alcohol will evaporate quickly and the traps will dry out. One advantage of pitfall traps is that they can be used to collect over a period of time with minimal maintenance and intervention. One disadvantage is that some species are not collected as they either avoid the traps or do not commonly encounter them while foraging.

Questions 27-30
Do the following statements agree with the information given in Reading Passage 118?
In boxes 27-30 on your answer sheet, write

TRUE if the statement agrees with the information
FALSE if the statement contradicts the information
NOT GIVEN if there is no information on this

27 Taxonomic research involves comparing members of one group of ants.
28 New species of ant are frequently identified by taxonomists.
29 Range is the key criterion for ecological collections.
30 A single collection of ants can generally be used for both taxonomic and ecological purposes.

Questions 31-36
Classify the following statements as referring to
 hand collecting
B  using bait
C  sampling ground litter
D  using a pitfall trap

Write the correct letter, A, B, C or D, in boxes 31-36 on your answer sheet.

31 It is preferable to take specimens from groups of ants.
32 It is particularly effective for wet habitats.
33 It is a good method for species which are hard to find.
34 Little time and effort is required.
35 Separate containers are used for individual specimens.
36 Non-alcoholic preservative should be used.

Questions 37-40
Label the diagram below.

Choose NO MORE THAN TWO WORDS from the passage for each answer.
Write your answers in boxes 37-40 on your answer sheet.

IELTS Academic Reading Sample 118
Click the button to Show/ Hide Answers

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