COLLECTING ANT SPECIMENS
Collecting ants can be as simple as picking up 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 abundances. 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 whole species in favour 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.
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 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 (1.5-3-0 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 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 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 in 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.
COLLECTING ANT SPECIMENS
- Giải thích từ vựng
- Specimen (n) /ˈspes.ə.mɪn/ mẫu, vật mẫu (để nghiên cứu, xét nghiệm)
Eg: He has a collection of rare insect specimens.
- Complicated (a) /ˈkɒm.plɪ.keɪ.tɪd/ phức tạp, rắc rối
Eg: I had to fill in this really complicated form.
Một số từ đồng nghĩa:
- Difficult it’s very difficult to find a job in this city.
- Hard the exam was really hard.
- Complex designing a house is a complex process.
- Tricky it’s quite tricky getting the puzzle pieces to fit together.
- Exhaustive (a) /ɪɡˈzɔː.stɪv/ hết mọi khía cạnh, hết mọi mặt, thấu đáo, toàn diện
Eg: This list is not intended to be exhaustive.
- Estimate (v) /ˈes.tɪ.meɪt/ ước lượng, đánh giá
Eg: Government sources estimate a long-term 50 percent increase in rail fares.
They estimate that the journey will take at least two weeks.
It was difficult to estimate how many trees had been destroyed.
Một số từ đồng nghĩa:
- Guess guess who called yesterday?
- Divine mum had divined my state of mind rather shrewdly.
- Surmise from the expression on his face, she surmised that something bad had happened.
- Conjecture it would be reasonable to conjecture that lack of exercise contributed to his obesity.
- Speculate a spokesperson declined to speculate on the cause of the plane crash.
- Taxonomy (n) /tækˈsɒn.ə.mi/ phép phân loại, nguyên tắc phân loại
Eg: It took a long time to develop ‘ a systematic, subject-based taxonomy for such a new field of study’, as the editors say.
- Desirable (a) /dɪˈzaɪə.rə.bəl/ đáng ao ước, đáng khát khao
Eg: Reducing class sizes in schools is a desirable aim.
It’s regarded as a highly desirable job.
The house is in a very desirable area of the city.
- Variation (n) /ˌveə.riˈeɪ.ʃən/ sự khác nhau, sự biến đổi
Eg: A mother’s ears are attuned to even the slightest variation in her baby’s breathing.
There have been wild variations in the level of spending.
- Identify (a) /aɪˈden.tɪ.faɪ/ nhận ra, nhận biết, nhận dạng
Eg: Even the smallest baby can identify its mother by her voice.
You need to identify your priorities.
Identificable (a)
- Compatible (a) /kəmˈpæt.ə.bəl/ hợp, thích hợp, tương hợp
Eg: It was when we started living together that we found we just weren’t compatible.
Most models of coffee maker are compatible with only certain brands of coffee pods.
- In favour of sth: thay thế bằng cái gì, để làm một cái gì khác
Eg: he abandoned teaching in favour of a career as a musician.
- Investigation (n) /ɪnˌves.tɪˈɡeɪ.ʃən/ sự điều tra nghiên cứu
Eg: An investigation has been under way for several days into the disappearance of a 13-year-old boy.
Investigate (v)
Collocation
-
- An investigation into sth an investigation into possible insider dealing has been begun by the stock exchange.
- The investigation of sth the investigation of the theft of a state data backup device last month continues.
- Launch/ conduct an investigation
- Criminal/civil/internal investigation
- Be under investigation (for sth) several companies are under investigation for fraud.
- Bait (n) /beɪt/ mồi nhử
Eg: they were digging up worms to use for bait.
- Pitfall (n) /ˈpɪt.fɔːl/ bẫy, cạm bẫy
Eg: The store fell into one of the major pitfalls of small business, borrowing from suppliers by paying bills late.
- Nocturnal (a) /nɒkˈtɜː.nəl/ (thuộc) đêm; về đêm
Eg: They are nocturnal creatures, which helps them avoid predators such as hawks and owls.
- Confine (v) /kənˈfaɪn/ hạn chế
Eg: Let’s confine our discussion to the matter in question, please!
Please confine your use of the phone to business calls.
- Moisten (v) /ˈmɔɪ.sən/ làm ẩm, dấp nước
Eg: Moisten the cloth before using it to clean glass.
He moistened his lips before he spoke.
- Sting (v) /stɪŋ/ (côn trùng) châm, chích, đốt
Eg: Do all types of bee sting?
Why do bees sting?
- Mishandle (v) /ˌmɪsˈhæn.dəl/ quản lý tồi; giải quyết hỏng
Eg: The police were accused of mishandling the investigation.
- Elusive (a) /iˈluː.sɪv/ hay lảng tránh, khó bắt
Eg: Eric, as elusive as ever, was nowhere to be found.
A solution to the problem of toxic waste is proving elusive.
- Situate (v) /ˈsɪtʃ.u.eɪt/ đặt ở vị trí, đặt chỗ cho
Eg: They plan to situate the bus stop at the corner of the road.
- Spot (v) /spɒt/ nhận ra, phát hiện ra
Eg: I’ve just spotted mark – he’s over there, near the entrance.
I soon spotted what was wrong with the printer.
Một số từ đồng nghĩa:
- See i can see for miles from up here.
- Notice i noticed a crack in the ceiling.
- Perceive bill perceived a tiny figure in the distance.
- Observe a teacher observed her climbing over the gate.
- Capture (v) /ˈkæp.tʃər/ bắt giữ, bắt
Eg: Rebel forces captured the city after a week-long battle.
One suspect has already been captured.
- Extract (v) /ɪkˈstrækt/ trích ra, tách ra
Eg: They used to extract iron ore from this site.
The oil which is extracted from olives is used for cooking.
- Marshy (a) /ˈmɑː.ʃi/ (thuộc) đầm lầy; như đầm lầy; lầy
Eg: This area was very marshy before the drainage system was installed.
- Sift (v) /sɪft/ sàng, lọc, rây (bột)
Eg: When the cake is cooked, sift some icing sugar over the top of it.
You will need 100g self-raising flour, sifted.
- Preservative (n) /prɪˈzɜː.və.tɪv/ chất bảo quản
Eg: The fence has been treated with preservative.
- Diameter (n) /daɪˈæm.ɪ.tər/ đường kính
Eg: The diameter measures twice the radius.
- Evaporate (v) /ɪˈvæp.ər.eɪt/ làm bay hơi, làm khô
Eg: The high concentration of sugars forms a syrup when the sap evaporates.
- Maintenance (n) /ˈmeɪn.tən.əns/ sự bảo dưỡng, chỉnh sửa, thay đổi
Eg: We have a large team of it staff who provide ongoing system and applications maintenance.
- Intervention (n) /ˌɪn.təˈven.ʃən/ sự xen vào, sự can thiệp
Eg: Half the people questioned said they were opposed to military intervention in the civil war.
Repeated interventions on the currency markets failed to prevent the currency’s value falling.
- Encounter (v) /ɪnˈkaʊn.tər/ gặp thình lình, bắt gặp
Eg: On their way home they encountered a woman selling flowers.
As we left the memorial area we encountered a group of german students.
- Range (n) /reɪndʒ/ phạm vi, loại, dãy
Eg: I offered her a range of options.
There is a wide range of opinions on this issue.
- Key (a) /kiː/ quan trọng, chủ chốt
Eg: She was a key figure in the international art world.
I think there is one key fact that you have overlooked.
- Criterion (n) /kraɪˈtɪə.ri.ən/ tiêu chuẩn, tiêu chí
Eg: Patients can now be compulsorily detained in hospital only under tightly drawn criteria.
The health service should not be judged by financial criteria alone.
Số nhiều: criteria
- Luyện tập
Bài 1: Chọn từ trong khung để hoàn thành các câu bên dưới
| exhaustive | encountered | nocturnal | spotted | bait |
| desirable | taxonomy | estimated | favour | pitfalls |
- The report includes a seemingly …………………… list of 160 benefits.
- Modern research into contemporary reading practices suggests a possible ………………….. of annotation practice.
- The ……………………… costs of the building project are well over £1 million.
- Early in his musical career he abandoned blues in …………………. of jazz.
- On my way to the station I ………………….. a small child, begging.
- The policewoman ………………… that I hadn’t got my seat belt on and signalled me to stop.
- We put down some poisoned ……………………… to kill the rats.
- He took financial advice on how to avoid the …………………….. of setting up your own business.
- The researchers live ………………… lives in order to study the animals.
- This underdeveloped area is much less ……………………… to investors than one of the major centres.
Bài 2: Chọn đáp án đúng để điền vào chỗ trống
- They are studying the …………… in carbon emissions. A. variation B. taxonomy
- Men have always played an active part in leading worship while women have been …………….. to more passive roles. A. estimated B. confined
- …………………. the tape with water before use. A. Moisten B. Mishandled
- The restaurant is ………………… near the Hudson River. A. situated B. spoted
- He was searching for the ever …………………. ‘perfect job’. A. elusive B. marshy
- Plants keep cool during the summer by ……………….. water from their leaves. A. encountering B. evaporating
- Astronauts brought back …………………. of moon rock. A. taxonomies B. specimens
- The relationship is a bi……………. He’s my mother’s cousin’s daughter’s child A. exhaustive B. complicated
- The research will be used to …………………. training needs. A. identify B. investigate
- A lengthy police ………………….. failed to produce any evidence on which the suspect could be convicted. A. investigation B. bait
- I didn’t see the nettles until I was ………………. by them. A. stung B. situated
- The entire campaign had been badly …………………….. A. spoted B. mishandled
- Several attempts were made to ………………….. the animal. A. capture B. extract
- Suburban settlement to the east of the city was much less extensive, in part because the ground was …………………. and traversed by streams. A. identified B. marshy
- Such policies are not ……………………… with democratic government. A. compatible B. exhaustive
- At the nuclear reprocessing plant they ………………… plutonium from spent atomic fuel rods. A. extract B. evaporate
- Biocides are active substances contained in products such as disinfectants and pesticides, as well as ……………………. A. pitfalls B. preservatives
- The pond is six feet in …………………………. A. diameter B. specimen
- ………………….. the flour finely before adding it to the mixture. A. Sift B. Evaporate
- We stock the full …………………. of model railway accessories. A. investigation B. range
- There is still some hope that the economic blockade will work and make military …………….. unnecessary. A. intervention B. investigation
- The city budget for street repair and ……………… was cut for this fiscal year. A. variation B. maintenance
Bài 1:
1.exhaustive 2. taxonomy 3. estimated 4. favour 5. encountered
- spotted 7. bait 8. pitfalls 9. nocturnal 10. desirable
Bài 2:
1.A 2. B 3. A 4. A 5. A
- B 7. B 8. B 9. A 10. A
- A 12. B 13. A 14. B 15.A
- A 17. B 18. A 19. A 20. B
21. A 22. B
