Biological control of pests
The continuous and reckless use of synthetic chemicals for the control of pests which pose a threat to agricultural crops and human health is proving to be counter-productive. Apart from engendering widespread ecological disorders, pesticides have contributed to the emergence of a new breed of chemical-resistant, highly lethal superbugs.
According to a recent study by the Food and Agriculture Organisation (FAO), more than 300 species of agricultural pests have developed resistance to a wide range of potent chemicals. Not to be left behind are the disease-spreading pests, about 100 species of which have become immune to a variety of insecticides now in use.
One glaring disadvantage of pesticides’ application is that, while destroying harmful pests, they also wipe out many useful non-targeted organisms, which keep the growth of the pest population in check. This results in what agroecologists call the ‘treadmill syndrome’. Because of their tremendous breeding potential and genetic diversity, many pests are known to withstand synthetic chemicals and bear offspring with a built-in resistance to pesticides.
The havoc that the ‘treadmill syndrome’ can bring about is well illustrated by what happened to cotton farmers in Central America. In the early 1940s, basking in the glory of chemical- based intensive agriculture, the farmers avidly took to pesticides as a sure measure to boost crop yield. The insecticide was applied eight times a year in the mid-1940s, rising to 28 in a season in the mid-1950s, following the sudden proliferation of three new varieties of chemical- resistant pests.
By the mid-1960s, the situation took an alarming turn with the outbreak of four more new pests, necessitating pesticide spraying to such an extent that 50% of the financial outlay on cotton production was accounted for by pesticides. In the early 1970s, the spraying frequently reached 70 times a season as the farmers were pushed to the wall by the invasion of genetically stronger insect species.
Most of the pesticides in the market today remain inadequately tested for properties that cause cancer and mutations as well as for other adverse effects on health, says a study by United States environmental agencies. The United States National Resource Defense Council has found that DDT was the most popular of a long list of dangerous chemicals in use.
In the face of the escalating perils from indiscriminate applications of pesticides, a more effective and ecologically sound strategy of biological control, involving the selective use of natural enemies of the pest population, is fast gaining popularity – though, as yet, it is a new field with limited potential. The advantage of biological control in contrast to other methods is that it provides a relatively low-cost, perpetual control system with a minimum of detrimental side-effects. When handled by experts, bio-control is safe, non-polluting and self-dispersing.
The Commonwealth Institute of Biological Control (CIBC) in Bangalore, with its global network of research laboratories and field stations, is one of the most active, non-commercial research agencies engaged in pest control by setting natural predators against parasites. CIBC also serves as a clearing-house for the export and import of biological agents for pest control world-wide.
CIBC successfully used a seed-feeding weevil, native to Mexico, to control the obnoxious parthenium weed, known to exert devious influence on agriculture and human health in both India and Australia. Similarly the Hyderabad-based Regional Research Laboratory (RRL), supported by CIBC, is now trying out an Argentinian weevil for the eradication of water hyacinth, ano ther dangerous weed, which has become a nuisance in many parts of the world. According to Mrs Kaiser Jamil of RRL, ‘The Argentinian weevil does not attack any other plant and a pair of adult bugs could destroy the weed in 4-5 days.’ CIBC is also perfecting the technique for breeding parasites that prey on ‘disapene scale’ insects – notorious defoliants of fruit trees in the US and India.
How effectively biological control can be pressed into service is proved by the following examples. In the late 1960s, when Sri Lanka’s flourishing coconut groves were plagued by leaf-mining hispides, a larval parasite imported from Singapore brought the pest under control. A natural predator indigenous to India, Neodumetia sangawani, was found useful in controlling the Rhodes grass-scale insect that was devouring forage grass in many parts of the US. By using Neochetina bruci, a beetle native to Brazil, scientists at Kerala Agricultural University freed a 12-kilometre- long canal from the clutches of the weed Salvinia molesta, popularly called ‘African Payal’ in Kerala. About 30,000 hectares of rice fields in Kerala are infested by this weed.
- Giải thích từ vựng
- Reckless (a) /ˈrek.ləs/ thiếu thận trọng, khinh suất, liều lĩnh, táo bạo
Eg: He was found guilty of reckless driving.
Một số từ đồng nghĩa:
- Careless That was careless of you.
- Sloppy Spelling mistakes always look sloppy in a formal letter.
- Slapdash His work is always hurried and slapdash.
- Rash That was a rash decision – you didn’t think about the costs involved.
- Thoughtless The Prime Minister made a thoughtless remark about the environment.
- Counter-productive (a) /ˌkaʊn.tə.prəˈdʌk.tɪv/ phản tác dụng, tác dụng ngược
Eg: Improved safety measures in cars can be counter-productive as they encourage people to drive faster.
Collocation
- counter-productive to sth State regulations have been counter-productive to the industry’s interests.
- Widespread (a) /ˌwaɪdˈspred/ lan rộng, phổ biến
Eg: There are reports of widespread flooding in northern France.
Malnutrition in the region is widespread – affecting up to 78 percent of children under five years old.
The campaign has received widespread support.
- Engender (v) /ɪnˈdʒen.dər/ sinh ra, gây ra, đem lại
Eg: Her latest book has engendered a lot of controversy.
- Lethal (a) /ˈliː.θəl/ làm chết người, gây chết người
Eg: Three minutes after the fire started, the house was full of lethal fumes.
In the car the police found guns, knives, and other lethal weapons.
Một số từ đồng nghĩa:
- Dangerous It’s dangerous to walk alone in the woods at night.
- Unsafe Don’t play in the street – it’s unsafe.
- Hazardous Heavy rain is causing hazardous driving conditions.
- Perilous A perilous journey through the mountains was their only escape route.
- Treacherous Ice had made the roads treacherous.
- Potent (a) có hiệu lực; hiệu nghiệm (thuốc…) / mạnh mẽ
Eg: Surprise remains the terrorists’ most potent weapon.
The Berlin Wall was a potent symbol of the Cold War.
This is a very potent drug and can have unpleasant side-effects.
Potency (n)
- Wipe out (phrasal verb): làm biến mất, quét sạch/ xóa bỏ, bỏ đi vật gì
Eg: A meteor ᴄraѕhing into the planet ᴡipeѕ the animal out.
Poor inᴠeѕtmentѕ ᴡiped out moѕt of hiѕ earningѕ.
- Tremendous (a) /trɪˈmen.dəs/ to lớn, khủng khiếp
Eg: They were making a tremendous amount of noise last night.
She’s been a tremendous help to me over the last few months.
Một số từ đồng nghĩa:
- Enormous
- Fantastic
- Wonderful
- Wondrous
- Withstand (a) /wɪðˈstænd/ chống lại, chống cự; chịu đựng
Eg: Our toys are designed to withstand the rough treatment of the average five-year-old.
- Offspring (n) /ˈɒf.sprɪŋ/ con, con cái, con cháu, con đẻ
Eg: In the case of the guinea pig, the number of offspring varies between two and five.
- Illustrate (v) /ˈɪl.ə.streɪt/ minh hoạ, làm rõ ý (bài giảng… bằng tranh, thí dụ…)
Eg: The lecturer illustrated his point with a diagram on the blackboard.
This latest conflict further illustrates the weakness of the UN.
- Avidly (adv) /ˈæv.ɪd.li/ say sưa, ngấu nghiến
Eg: She reads avidly.
We avidly awaited news of him.
I listened avidly to the early recordings of Louis Armstrong and Duke Ellington.
- Glory (n) /ˈɡlɔː.ri/ thời kỳ hưng thịnh, thời kỳ vinh hiển/ vinh quang
Eg: He basked in the glory of his victory.
Winning the championship was the crowning glory of her career.
- Proliferation (n) /prəˌlɪf.ərˈeɪ.ʃən/ sự nảy nở, tăng nhanh
Eg: The proliferation of cell phones has changed how we communicate.
The past two years have seen the proliferation of TV channels.
The proliferation of wireless and broadband services is continuing.
- Outbreak (n) /ˈaʊt.breɪk/ sự bột phát, sự bùng nổ
Eg: Last weekend saw further thundery outbreaks.
On the outbreak of the Pindari War in 1817 the British government offered its protection.
- Necessitate (v) /nəˈses.ɪ.teɪt/ bắt phải, đòi hỏi phải, cần phải có
Eg: Reduction in government spending will necessitate further cuts in public services.
Collocation
- necessitate doing something
- necessitate somebody/something doing something
- Outlay (n) /ˈaʊt.leɪ/ tiền chi tiêu, tiền phí tổn
Eg: For an initial outlay of $2,000 to buy the equipment, you can earn up to $500 a month if the product sells well.
Few are able to afford the cash outlay.
It’s low cost, with no significant cash outlay at the outset.
- Invasion (n) /ɪnˈveɪ.ʒən/ sự xâm lược, sự xâm chiếm, sự xâm lấn/ sự lan tràn
Eg: I certainly regarded the tapping of my phone as an invasion of privacy.
Invasive (a)
- Adverse (a) /ˈæd.vɜːs/ bất lợi, có hại
Eg: The match has been cancelled because of adverse weather conditions.
They received a lot of adverse publicity/criticism about the changes.
So far the drug is thought not to have any adverse effects.
Reactions to the proposal so
Một số từ đồng nghĩa:
- Disadvantageous
- Inauspicious
- Unfavourable
- Mutation (n) /mjuːˈteɪ.ʃən/ đột biến/ sự thay đổi, sự biến đổi
Eg: Environmental pressures encourage genes with certain mutations to persist and others to die out.
These plants carry the mutation for red flowers.
These cells have been affected by mutation.
The disease is caused by genetic mutations.
Mutate (v)
- Peril (n) /ˈper.əl/ sự nguy hiểm, hiểm hoạ, cơn nguy
Eg: I never felt that my life was in peril.
The journey through the mountains was fraught with peril.
Teenagers must be warned about the perils of unsafe sex.
The president said that we are entering a time of great peril.
- Indiscriminate (a) /ˌɪn.dɪˈskrɪm.ɪ.nət/ không phân biệt, bừa bãi
Eg: The indiscriminate use of fertilizers can cause long-term problems.
Cancer is completely indiscriminate in whom it strikes.
Doctors have been criticized for their indiscriminate use of antibiotics.
The indiscriminate use of pesticides is now banned.
- Perpetual (a) /pəˈpetʃ.u.əl/ vĩnh viễn, bất diệt/ không ngừng
Eg: They lived in perpetual fear of being discovered.
He has hard, cold eyes and his mouth is set in a perpetual sneer.
- Detrimental (a) /ˌdet.rɪˈmen.təl/ có hại, thiệt hại cho; bất lợi cho
Eg: These chemicals have a detrimental impact on the environment.
Their decision could be detrimental to the future of the company.
Một số từ đồng nghĩa:
- Damaging
- Deleterious
- Harmful
- Injurious
- Prejudicial
- Side-effect (n) /ˈsaɪd ɪˌfekt/ tác dụng phụ
Eg: The drug has few side-effects.
Side-effects include skin rashes and nausea.
- Parasite (n) /ˈpær.ə.saɪt/ vật ký sinh, ký sinh trùng
Eg: The older drugs didn’t deal effectively with the malaria parasite.
- Eradication (n) /ɪˌræd.ɪˈkeɪ.ʃən/ sự nhổ rễ, sự trừ tiệt
Eg: The organization’s goal is the eradication of poverty.
The department faces either a budget cut or eradication.
Eradicate (v)
- Nuisance (n) /ˈnjuː.səns/ mối gây thiệt hại, mối gây khó chịu, mối làm phiền toái, mối làm rầy, mối làm phiền
Eg: I’ve forgotten my umbrella – what a nuisance!
It’s such a nuisance having to rewrite those letters.
Một số từ đồng nghĩa:
- Annoyance The café was cash only, which was a minor annoyance as I only had my credit card with me.
- Inconvenience Thank you for holding – we apologize for the inconvenience.
- Irritation The CEO’s poor communication skills became a source of irritation to the company’s investors.
- Irritant The noise of the building work is a constant irritant.
- Bore It’s such a bore to have to pack everything up again.
- Notorious (a) /nəʊˈtɔː.ri.əs/ rõ ràng, hiển nhiên, ai cũng biết
Eg: The company is notorious for paying its bills late.
The city is notorious for its red light district and strip clubs.
Một số từ đồng nghĩa:
- Famous She went from poor and anonymous to rich and famous.
- well known She’s a well-known artist.
- Renowned The area is renowned for its beauty.
- world-famous They stayed in a world-famous hotel.
- Celebrated He’s a celebrated writer of children’s stories.
- Legendary He once met the legendary singer, Eartha Kitt.
- Infest (v) /ɪnˈfest/ tràn vào quấy phá, tràn vào phá hoại (sâu bọ, giặc cướp…)
Eg: The barn was infested with rats.
Collocation
- be infested (with something)
- Innate (a) /ɪˈneɪt/ bẩm sinh
Eg: Cyril’s most impressive quality was his innate goodness.
Her dance expresses the innate beauty of the human spirit.
He never lost his innate sense of fun.
- Luyện tập
Bài 1: Chọn từ trong khung để hoàn thành các câu bên dưới
| lethal | widespread | illustrates | glory | nuisance |
| avidly | engendered | infest | outlay | peril |
- The next 36 hours will be even colder with snow showers becoming more …………….………..
- The place …………….………..immediate feelings of friendship and belonging.
- That combination of tiredness and alcohol is …………….………..
- Last year she began to exercise ………………. and walk for two hours every day.
- This was her final professional match, and she wanted to end her career in a blaze of …………………
- The incident graphically ……………….. just how dangerous the situation in the war zone has become.
- This technology will require an initial ……………….., but it will produce long-term savings.
- The president said that we are entering a time of great ……………………..
- These parasites …………………….. the gills of freshwater fish.
- Local residents claimed that the noise was causing a public …………………….
Bài 2: Chọn đáp án đúng để điền vào chỗ trống
- These species of weeds are stubbornly resistant to ……………………… A. eradication B. nuisance
- He has spent the past three months in Florida, ostensibly for medical treatment, but in actual fact to avoid prosecution for a series of ….…………… armed robberies. A. innate B. notorious
- Your contaminated fingers can transmit the ……………………. to many surfaces. A. parasite B. perpetual
- The disease is caused by genetic ………………….. A. mutations B. invasionss
- Champion horses have numerous …………………… A. offspring B. glory
- The ……………….. of social media platforms has meant people can be constantly in touch in a variety of ways. A. invasion B. proliferation
- Increased traffic ………………… widening the road. A. necessitated B. engendered
- He pleaded innocent to ………….…….. driving charges. A. lethal B. reckless
- Stringent cost management is ……………..…. when it prevents a company from growing. A. counter-productive B. widespread
- On the ………………… of the Pindari War in 1817 the British government offered its protection. A. mutation B. outbreak
- He attracted a lot of …………………. publicity with his speech about unmarried mothers. A. adverse B. detrimental
- Chemotherapy can have some very unpleasant …………………. A. parasites B. side-effects
- Emissions from the factory are widely suspected of having a ……………………. effect on health. A. detrimental B. perpetual
- The newspaper denounced the ………………….. firing by the police. A. widespread B. indiscriminate
- Her voice has been a …………………….. force on concert stages for more than 30 years. A. potent B. lethal
- Robberies and home ……………… are grim facts of daily life. A. outlays B. invasions
- We lived for years in a ……………. state of fear. A. perpetual B. adverse
- Many children seem to have an …………………….. sense of justice. A. notorious B. innate
- The aircraft base is protected with specially designed shelters which are built to …………….. ground and air attacks. A. withstand B. adverse
- She has every right to be proud of her ……………… achievements. A. adverse B. tremendous
- Whole the ᴄitу ᴡaѕ ……………. out due to a tѕunami. A. ᴡiped B. withstood
Bài 1:
1.widespread 2. engendered 3. lethal 4. avidly 5. glory
- illustrates 7. outlay 8. peril 9. infest 10. nuisance
Bài 2:
1.A 2. B 3. A 4. A 5. A
- B 7. A 8. B 9. A 10. B
- A 12. B 13. A 14. B 15.A
- B 17. A 18. B 19. A 20. B
