Test 04-Passage 3:Collecting Ant specimens 纠错
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Collecting ants can be as simple as picking up a stray 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 abundance. 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 of variation within species. For ecological 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 the whole species in favor of those groups currently under study, while the ecologist often collects only a limited number of specimens of each species, thus reducing their value for taxonomic investigations.

收集蚂蚁可以很简单,将一只只单独行动的蚂蚁捡起放入玻璃罐中即可。这个过程也可以很复杂,比如完成对一个地区所有物种的详细调查,并且判断它们的相对丰富度。到底使用哪种方法将取决于采集的最终目的。如果出于分类学的目的(也就是归类),可以通过锁定一个蚁巢中包含所有蚁种(包括主要的和次要的工蚁,也包括可能存在的蚁后和蚁王)的一系列样本来确定物种的变种。如果是以生态学研究为目的,最重要的因素就是尽可能多地采集现有不同物种的可辨认样本。然而遗憾的是,这两种方法通常不兼容。分类学家们有时倾向于采集研究中的种群标本而忽视了整个物种,而生态学家们经常只是搜集每个物种的一定数量的样本,因此也就降低了这些样本的分类研究价值。

To collect as wide a range of specimens as possible, several methods must be used. These include hand collecting, using baits to attract ants, ground litter sampling, and the use of pitfall traps. Hand collecting consists of searching for ants everywhere they are likely to occur. This include on the ground, under rocks, logs or other objects on the ground, in rotten woods on the ground or on trees, in vegetation, on tree trunks and under bark. When possible, collections should be made from nests and foraging columns and at least 20-25 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 combined to daytime. Specimens are collected using an aspirator (often called a pooter), 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 ml capacity for small ants, 5-8 ml for larger ants) containing 75%-95% ethanol. Plastic tubes with secure tops are better than glass because they are lighter, and do not break as easily if mishandled.

为了尽可能广泛地搜集物种,我们必须运用多种方法。这些方法包括手工采集法、诱饵采集法、落叶层抽样法和陷阱采集法。手工采集法就是去蚂蚁可能出现的所有地方搜集,包括地面、石头下、原木或地面的其他物体上、地面上的朽木里或树上、植被里、树干上以及树皮下。有可能的话,采集应当从蚁巢或觅食蚂蚁群开始搜集,而且至少采集20至25只蚂蚁。这样就确保了所有蚂蚁个体都属同一物种,从而也提高了详细研究的价值。由于有些物种主要在夜间活动,所以采集不应仅限于白天。标本采集可以使用抽吸器(通常称之为吸虫管)、钳子、质量好的湿油漆刷、或者如果知道蚂蚁不咬人的话,可直接用手采集。单只昆虫可以放在浓度为75%至95%酒精的塑料管或玻璃管(1.5~3.0毫升容量用于小蚂蚁,5~8毫升容量用于较大的蚂蚁)中。塑料管较轻,且万一处理不当的话不易破碎,所以带安全塞的塑料管比玻璃管更好。

Baits can be used to attract and concentrate foragers. This often increases the number of individuals collected and attracts species that are otherwise elusive. Sugar, meat and oils 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-colored surfaces, or in test-tubes or vials. This makes it easier to spot ants and capture them before they can escape into the surrounding leaf litter.

诱饵可用来吸引和聚拢觅食者。这种方法通常能够增加采集的个体量,还能吸引那些难以捕捉的物种。我们应该使用糖、肉或油,因为它们能引诱多个不同的物种。这些诱饵可以放置在地面上、树干上或者大灌木丛中。放在地面上时,诱饵应该被放在小纸板或其他平整、浅色的表面上,或者放在试管及小瓶中。这样更容易发现蚂蚁,并且能在它们逃到周围的树叶堆中之前抓住它们。

Many ants are small and forage primarily in the layers 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 on a large funnel, often under some heat. As the 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 worked especially well in rain forests 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 the larger leaves and twigs. It will also allow more litter to be sampled when using a limited number of funnels.

许多蚂蚁体型小,主要在地面上的树叶层中间和其他废物中觅食。用手采集这些蚂蚁比较困难,最成功的采集方法之一就是聚集蚂蚁们正在其中觅食的落叶,然后从中取出蚂蚁。通常,我们将这些落叶放置在筛子上,下方是一个大漏斗。往往在对漏斗上方进行加热时,随着上面的叶子渐渐变干,蚂蚁(和其他动物)就会向下移动,最终掉下来,从漏斗底部漏出,这样就被收集到了置于漏斗下方的酒精中。这个方法特别适用于雨林和沼泽地区。使用漏斗时,可先用一张粗网筛一下落叶,然后再把落叶放置在漏斗上方,这是一种增加收集量的方法,因为这样做能够去掉大树叶和小树枝,从而把落叶集中起来。在漏斗数量有限的情况下,也能够对更多的落叶进行取样。

The pitfall trap is another commonly used tool for collecting ants. A pitfall trap can be any small container placed in the ground with the top level with the surrounding surface and filled with preservative. Ants are collected when they fall into the trap while foraging. The diameter of the trap can vary from about 18 mm to 10 cm and the number used can from a few to several hundred. The size of the trap used is influenced largely by personal preference (although larger size 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.

陷阱是另一个常用的收集蚂蚁的工具。陷阱可以是任何一个放在地面上的盛有防腐剂的小容器,容器的顶部应与其周围地表保持水平。当蚂蚁出来觅食时,掉进陷阱就被捉到了。陷阱瓶的直径约为18毫米到10厘米不等。使用数量也可以是几个到几百个不等。陷阱瓶的大小主要由个人喜好决定(虽然较大的瓶子通常比较好)。但其数量则由正在进行的研究所决定。由于酒精易挥发,瓶子很快就会干了,所以我们使用的防腐剂通常是乙二醇或丙二醇。陷阱采集法的一个优势在于,仅仅需要极少的维护和干预,它们就能够持续使用一段时间。它的一个缺点是,因为有些物种要么会避开陷阱,要么外出觅食时通常碰不到陷阱,所以用这种方法就采集不到这些蚂蚁。

Do the following statements agree with the information given in Reading Passage 3?

In boxes 27-30 on your answer sheet, write

TRUE if the statement agrees with the information given in the text.
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.

  •  TRUE
  •  FALSE
  •  NOT GIVEN
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正确答案: TRUE

28 New species of ant are frequently identified by taxonomists.

  •  TRUE
  •  FALSE
  •  NOT GIVEN
显示答案
正确答案: NOT GIVEN

29 Range is the key criterion for ecological collections.

  •  TRUE
  •  FALSE
  •  NOT GIVEN
显示答案
正确答案: TRUE

30 A single collection of ants can generally be used for both taxonomic and ecological purposes.

  •  TRUE
  •  FALSE
  •  NOT GIVEN
显示答案
正确答案: FALSE

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Collecting Ant specimens

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