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Academic Reading Passage 2: Biological Pest Control
If you’re doing the Computer Delivered Test and would like to practice your Reading online, here’s a
link I found.
Biological Pest Control
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,
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Academic Reading Passage 2: Biological Pest Control
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, another 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.
Questions 1-4
Choose the correct letter, A, B, C, or D.
Write the correct letter in boxes 1-4 on your answer sheet.
1 The use of pesticides has contributed to
A a change in the way ecologies are classified by agroecologists.
B an imbalance in many ecologies around the world.
C the prevention of ecological disasters in some parts of the world.
D an increase in the range of ecologies which can be usefully farmed.
2 The Food and Agriculture Organisation has counted more than 300 agricultural pests which
A are no longer responding to most pesticides in use.
B can be easily controlled through the use of pesticides.
C continue to spread disease in a wide range of crops.
D may be used as part of bio-control’s replacement of pesticides.
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Academic Reading Passage 2: Biological Pest Control
3 Cotton farmers in Central America began to use pesticides
A because of an intensive government advertising campaign.
B in response to the appearance of new varieties of pest.
C as a result of changes in the seasons and the climate.
D to ensure more cotton was harvested from each crop.
4 By the mid-1960s, cotton farmers in Central America found that pesticides
A were wiping out 50% of the pests plaguing the crops.
B were destroying 50% of the crops they were meant to protect.
C were causing a 50% increase in the number of new pests reported.
D were costing 50% of the total amount they spent on their crops.
Questions 5-8
Do the following statements agree with the claims of the writer in Reading Passage 2?
YES if the statement agrees with the claims of the writer
NO if the statement contradicts the claims of the writer
NOT GIVEN if it is impossible to say what the writer thinks about this
5 Disease-spreading pests respond more quickly to pesticides than agricultural pests do.
6 A number of pests are now born with an innate immunity to some pesticides.
7 Biological control entails using synthetic chemicals to try and change the genetic make-up of the
pests’ offspring.
8 Bio-control is free from danger under certain circumstances.
Questions 9-13
Complete each sentence with the correct ending, A-I, below.
A forage grass. F parthenium weed.
B rice fields. G Brazilian beetles.
C coconut trees. H grass-scale insects.
D fruit trees. I larval parasites.
E water hyacinth.
9 Disapene scale insects feed on
10 Neodumetia sangawani ate
11 Leaf-mining hispides blighted
12 An Argentinian weevil may be successful in wiping out
13 Salvinia molesta plagues
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Academic Reading Passage 2: Biological Pest Control
Answers
1. B
2. A
3. D
4. D
5. NOT GIVEN
6. YES
7. NO
8. YES
9. D
10. H
11. C
12. E
13. B
Explanations
Questions 1-4
Choose the correct letter, A, B, C, or D.
1 The use of pesticides has contributed to
B an imbalance in many ecologies around the world.
Apart from engendering widespread ecological disorders, pesticides have contributed to the emergence
of a new breed of chemical-resistant, highly lethal superbugs.
2 The Food and Agriculture Organisation has counted more than 300 agricultural pests which
A are no longer responding to most pesticides in use.
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.
3 Cotton farmers in Central America began to use pesticides
D to ensure more cotton was harvested from each crop.
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.
4 By the mid-1960s, cotton farmers in Central America found that pesticides
D were costing 50% of the total amount they spent on their crops.
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Academic Reading Passage 2: Biological Pest Control
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.
Questions 5-8
5 Disease-spreading pests respond more quickly to pesticides than agricultural pests do. Not Given
There is no comparison in the text.
6 A number of pests are now born with an innate immunity to some pesticides. Yes
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.
7 Biological control entails using synthetic chemicals to try and change the genetic make-up of the
pests’ offspring. No
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.
8 Bio-control is free from danger under certain circumstances. Yes
When handled by experts, bio-control is safe, non-polluting and self-dispersing.
Questions 9-13: Try to ignore the impossible-to-know words: just look for a match in the sentence.
9 Disapene scale insects feed on D
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.
10 Neodumetia sangawani ate H
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.
11 Leaf-mining hispides blighted C
In the late 1960s, when Sri Lanka’s flourishing coconut groves were plagued by leaf-mining hispides,...
12 An Argentinian weevil may be successful in wiping out E
Similarly the Hyderabad-based Regional Research Laboratory (RRL), supported by CIBC, is now trying out
an Argentinian weevil for the eradication of water hyacinth, …
13 Salvinia molesta plagues B
...Salvinia molesta, popularly called ‘African Payal’ in Kerala. About 30,000 hectares of rice fields in
Kerala are infested by this weed.
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Academic Reading Passage 2: Biological Pest Control
AMAZING vocabulary you need to know/learn (70% of the text basically!)
● The continuous and reckless use of synthetic chemicals…
● Engendering widespread ecological disorders
● An imbalance in many ecologies around the world
● Chemical -resistant
● Pests have developed resistance to chemicals
● Pests have become immune to insecticides
● To withstand synthetic chemicals
● While destroying harmful pests, they also wipe out many useful organisms
● Genetic diversity
● To bear offspring
● built-in/innate resistance
● Chemical-based intensive agriculture
● To boost crop yield
● Invasion of genetically stronger insect species
● Cause cancer and other adverse effects on health
● More effective and ecologically sound strategy of biological control
● Selective use of natural enemies
● Is fast gaining popularity
● Detrimental side-effects
● Non-polluting
● Setting natural predators against parasites
● Eradication/ To wipe out
● It has become a nusanceindigenous to India
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anchor.fm/ieltsetc, facebook/ieltsetc, i nstagram@ieltsetc , YouTube and Flipboard
