Chapter 17 sixteen crash rumble

If Darwin were alive today, he would be delighted and amazed by the impressive validation of the insect world's theory of survival of the fittest.Under the weight of aggressive chemical spraying, the weakest of the insect populations were wiped out.Now, in many regions and in many species, only the hardy and well-adapted insects have survived counter-control. Nearly half a century ago, A. L. Myland, a professor of entomology at Washington State University, asked what now appears to be a purely rhetorical question: "Can insects gradually become resistant to spraying?" If If the answers given to Myland at the time seemed unclear or too slow, it was only because his questions were asked too quickly—he asked them in 1914, not forty years later.Prior to the days of DDT, the use of inorganic chemicals on a scale that would seem prudent today has everywhere caused strains in insects that survived the sprays.Mylander himself was plagued by the San Goose scale insect, which he spent several years controlling satisfactorily with sulphurized lime sprays; The insects have become tenacious—they are harder to kill than they were in orchards in the Wannatchee and Yajima Valleys.

Suddenly, the scale insects in other parts of the United States seem to have the same idea: They don't want to die anymore, given the diligent and generous spraying of sulphurized lime by orchard growers.Thousands of acres of fine orchards in the American Midwest have been wiped out by the now spray-resistant insect. In California, however, the issue has been raised when a long-promoted method—covering trees in canvas tents and fumigation with hydrocyanic acid vapors—is starting to produce disappointing results in some areas. Go to the California Citrus Experimental Station, which began around 1915 and continued for a quarter of a century.Although lead arsenate has been successful against cod moths for forty years, in the 2020s the moth became an insect resistant to the drug.

However, it was only with the advent of DDT and its ilk that the world was ushered in the era of true drug resistance.It should not surprise anyone with even the simplest knowledge of insects or of animal population dynamics that in a few years or so an unpleasant and dangerous problem has clearly manifested itself .Although insects have slowly become known to have the ability to resist chemicals, it seems that only those who deal with disease-carrying insects are aware of the seriousness of the situation; basis, but most agricultural workers are still happily hoping to develop new and increasingly toxic chemicals.

Much time has been devoted to understanding the phenomenon of insect resistance, but far less time has been spent to develop insect resistance itself.Before 1945, only about a dozen species of insects were known to have developed resistance to certain pre-DDT insecticides.With the advent of new organic chemicals and new methods for their widespread use, resistance began to develop rapidly, reaching 137 insect species resistant by 1960.No one believed that this was the end of the matter.No fewer than 1,000 technical reports have been published on this subject.The World Health Organization, sponsored by some 300 scientists from around the world, declared that "drug resistance is now the single most important problem against targeted control programmes".Dr. Carls Ayrton, a prominent British fauna researcher, once said: "We are hearing an early rumble that may develop into a gigantic collapse".

Resistance develops so rapidly that sometimes another corrective report has to be issued before the ink is dry on a report celebrating the success of a chemical in controlling an insect.For example, in South Africa, ranchers have been troubled by blue ticks for a long time, and 600 cows in one large pasture alone play with them every year.Over the years, the ticks have developed resistance to arsenic sprays.Then, 666 was tried again, and for a short period everything seemed satisfactory.Reports as early as 1949 claimed that arsenic-resistant ticks could be easily controlled by the new chemical.But the following year, a sad announcement that insect resistance was moving forward had to be published.This situation prompted a writer to comment in the "Leather Business Review" in 1950: "Such news that leaks out quietly through scientific exchanges and only occupies a small position in foreign books and periodicals is fully qualified to be published in newspapers." A headline as big as news of a new atomic bomb would appear on the Internet, if the significance of the event were fully understood."

While insect resistance is a matter of concern to agriculture and forestry, it also raises serious concerns in the public health arena.The relationship between various insects and many human diseases is an old question.Anofiles mosquitoes can inject single cells of malaria into the bloodstream.Another species of mosquito can transmit yellow fever.There are other mosquitoes that transmit encephalitis.The housefly does not bite, but it can contaminate human food through contact with Shigella and plays an important role in the transmission of eye diseases in many parts of the world.The list of diseases and their insect carriers (i.e., vectors) included the lice that carried typhus, the rat flea that carried plague, the apple fly that carried African sleeping sickness, the ticks that carried various types of fever, and so on.

These are important questions that we are bound to encounter.No responsible person would think that these insect-borne diseases can be ignored.Now we are faced with a question: Is it smart, and responsible, to address this problem in ways that are exacerbating it?Our world has heard many stories of victory over disease by controlling insect infectors, but our world has hardly heard the other side of the news—the failure side, the short-lived victory that now strongly supports such In one case, our enemies, insects, have actually become stronger by our efforts.Even worse, we may have destroyed our own means of warfare.

A distinguished Canadian entomologist, Dr. A. W. A. ​​Brown, was hired by the World Health Organization to conduct an extensive investigation into the problem of insect resistance.In a concluding monograph published in 1958, Dr Brown wrote: "Not even a decade after the introduction of highly toxic artificial insecticides into public health programs, the major technical problem has manifested itself in the development of resistance to the insecticides that control them." In his published monograph, the World Health Organization warns: The vigorous onslaught of disease is in danger of a serious retreat unless this new problem is quickly addressed."

What is the extent of this regression?The list of resistant insects now includes virtually the entire range of insects of medical interest.Black flies, sand flies, and fly flies do not appear to be developing resistance to the chemicals.On the other hand, resistance in house flies and clothes lice has now developed on a global scale.Plans to conquer malaria have run into difficulties due to mosquito resistance.The oriental rat flea, the main transmitter of plague, has recently demonstrated resistance to DDT, a most serious development.Every continent and most islands are reporting local resistance in many species of insects.

It might be argued that the first medical application of modern insecticides was in Italy in 1943, when the Allied government succeeded in eradicating typhus by dusting large numbers of people with DDT powder.Then, two years later, extensive residual spraying was carried out for the control of malaria mosquitoes.A sign of trouble emerged just a year later, when houseflies and mosquitoes began to show resistance to the sprayed drug. In 1948, a new chemical, chlordane, was tried as a supplement to DDT.This time, effective control was maintained for two years; however, by August 1950, chlordane-resistant mosquitoes had also appeared, and by the end of the year, all houseflies appeared to be resistant to chlordane, as were mosquitoes.Resistance develops as soon as new chemicals are introduced.Near the end of 1951, DDT, methoxyheptachlor, chlordane, heptachlor, and HHC were all included in the list of expired chemical substances.At the same time, the flies became "surprisingly plentiful".

In the late 1940s, the same sequence of events repeated itself in Sardinia.In Denmark, drugs containing DDT were first used in 1944; by 1947, fly control had failed in many places.In some parts of Egypt, flies had developed resistance to DDT by 1948; BHC was used instead, but only for a year.An Egyptian village highlights this problem. Insecticides effectively controlled the flies in 1950, and in the same year the initial mortality dropped by nearly 50%.The following year, the flies became resistant to DDT and chlordane, and the number of flies returned to the original level, and the mortality rate also dropped to the original level.In the United States, flies in the Tennessee Valley had become resistant to DDT by 1948.This happened in other regions as well.Efforts to restore control with dieldrin were in vain, because in some places the flies acquired a hardy resistance to the drug in as little as two months.After the widespread use of potent chlorinated hydrocarbons, the controls shifted to organophosphates; here, however, the resistance story repeated itself.The experts have now concluded that "insecticide technology is no longer a solution to the problem of housefly control and general sanitation must be reverted to". The control of clothes lice in Naples was one of DDT's first and best-known successes.In later years, its success in Italy was compared to its success in Japan and Korea during the winter of 1945-1946 in eradicating lice, which infested a population of about two million people. In 1948, the typhus epidemic in Spain failed. Through this failure, we know that the future work will be difficult.Despite this failure, successful indoor experiments convinced entomologists that lice would not necessarily develop resistance; but events in North Korea during the winter of 1950-1951 surprised them.When DDT powder was used on a group of North Korean soldiers, the unusual result was that the lice became more rampant.When lice were collected for testing, it was found that 5% DDT powder did not cause an increase in their natural mortality.The same results were obtained for lice collected from homeless people in Tokyo, the Itabashe shelter, and refugee camps in Syria, Jordan, and eastern Egypt, and these results confirmed the ineffectiveness of DDT for controlling lice and typhus.By 1957, the list of countries with DDT-resistant lice had expanded to include Iran, Turkey, Ethiopia, West Africa, South Africa, Peru, Chile, France, Yugoslavia, Afghanistan, Uganda, Mexico, and Tanganyika.The first ecstasy in Italy seemed to have really dimmed. The first Anopheles mosquito to develop resistance to DDT was Anopheles sarbachii in Greece. Intensive spraying began in 1946 with initial success; by 1949, however, observers noticed large numbers of adult mosquitoes resting under road bridges rather than in sprayed rooms and stables.The places where the mosquitoes rested outside quickly spread to caves, outhouses, gutters, and the foliage and trunks of orange trees.Apparently, the adult mosquitoes had become sufficiently resistant to DDT that they were able to escape the sprayed buildings and rest and recover in the open.After a few months, they were able to remain in the house, where they were found resting on the sprayed walls. This is a precursor to a very serious situation that is now emerging.Anopheles mosquitoes have grown extremely rapidly resistant to insecticides, a development created entirely by the very thoroughness of the house-spraying programs aimed at eradicating malaria.In 1956, only 5 species of Anopheles mosquitoes showed resistance; by the beginning of 1960, the number had increased from 5 to 28 species!These include very dangerous malaria transmitters in West Africa, Central America, Indonesia and Eastern Europe. This is also being repeated in mosquitoes that transmit other diseases.A tropical mosquito that carries a parasite linked to diseases such as rubber blight has become highly resistant in many parts of the world.Mosquitoes that transmit Western equine encephalitis have developed resistance in some parts of the United States.A far more serious problem has to do with the spread of yellow fever, a disease that has plagued the world for centuries.The development of such mosquito resistance has appeared in Southeast Asia and is now a common phenomenon in the Caribbean. Reports from many parts of the world show the impact of insect resistance on malaria and other diseases.In Trinidide, the yellow fever outbreak of 1954 followed the failure of control of the mosquitoes responsible for the disease as the mosquitoes developed resistance.In Indonesia and Iran, malaria is active again.In Greece, Nigeria, and Libya, mosquitoes continued to hide and spread the malaria parasite. The reduction in diarrheal disease achieved by fly control in Georgia has been wiped out in a year's time.In Egypt, the reduction in acute conjunctivitis achieved by temporary control of flies disappeared after 1950. One thing that's not too serious in terms of human health, but a headache in terms of economic value, is that mosquitoes in Florida's salt marshes have also shown resistance.Although these mosquitoes do not transmit disease, they come out in swarms to feed on human blood, leaving vast areas of the Florida coast uninhabited until control—a difficult and temporary control that The situation changed; however, this effect quickly disappeared again. The fact that the common house mosquito is developing resistance everywhere should give pause to many of the villages that are now undergoing regular mass spraying.In Italy, Israel, Japan, France and parts of the United States including California; Ohio, New Jersey and Massachusetts, the mosquito is now resistant to harsh insecticides, the most widely used of which are DDT. Ticks are another problem.The wood tick, the vector of encephalomyelitis, has recently developed resistance, and the brown dog tick's ability to resist chemical virulence has been completely and widely established.This situation is a problem for humans as well as for dogs.The brown dog tick is a subtropical species, and when it occurs in the great north like New Jersey, it must winter in a building with water outside that is much warmer.J. C. Palist of the American Museum of Natural History reported in the summer of 1959 that his exhibition department had received many calls from neighbors in West Central Park. Mr. Palist said: "The whole house is often infected on young ticks, and are very hard to get rid of. A dog will get ticks by accident in Central Park, and the ticks lay eggs that hatch in the house. It seems they are very sensitive to DDT, chlordane, or other we Most of the drugs that are used now are immune. Ticks used to be very unusual in New York City, and now they're all over the city and Long Island, all over West Chester, and spreading to Connecticut. This situation has given us special attention in the last five or six years." The German beetle, which spreads across many parts of North America, has become resistant to chlordane, once the favorite weapon of exterminators who are now forced to switch to organophosphates.However, with insects currently developing resistance to these insecticides, this raises a question for exterminators: what next? Because of increasing insect resistance, those working against insect-borne diseases are now forced to substitute one insecticide for another to cope with the problems they face.However, this approach cannot be continued indefinitely without the invention of chemists to supply new substances.Dr. Brown has pointed out that we are traveling on "a one-way street" no one knows how long; and we are indeed in dire straits if disease-carrying insects are not controlled before we reach the end of death up. The list of a dozen or so agricultural insects resistant to early inorganic chemicals should now be added by another large group of insects resistant to DDT, BHC, HCB, toxaphene, dieldrin, Aldrin, and even the phosphorus resistance that people had hoped for. In 1960, 65 crop-damaging insect species were resistant. The first examples of agricultural insect resistance to DDT appeared in the United States in 1951, about six years after DDT was first used.Perhaps the hardest-to-control situation has to do with the cod moth, which is actually now resistant to DDT in apple-growing regions of the world.Resistance in cabbage insects is becoming another serious problem.Potato insects are escaping chemical control in many parts of the United States.Six species of cotton insects, rice eaters of all varieties, fruit moths, leaf locusts, caterpillars, mites, aphids, iron nematodes, and many others are now oblivious to the spraying of chemicals by farmers. The chemical industry's reluctance to confront the unpleasant reality of drug resistance is perhaps understandable right now.Even as late as 1959, 100 major insect species had become significantly resistant to chemicals.At this point, a major agricultural chemistry journal was asking whether insect resistance was "real or imagined."However, while the chemical industry sector has hopefully turned its face away, the problem of insect resistance has not simply disappeared, and it has also presented some unpleasant economic facts for the chemical industry.It is a fact that the cost of insect control with chemicals is constantly increasing.Since an insecticidal chemical that may seem promising today may fail miserably tomorrow, it no longer makes sense to stockpile insecticides in advance.When the resistance of these insects once again proves the ineffectiveness of human violence against nature, the large financial investment used to support and promote insecticides may be cancelled.Of course, rapidly advancing technology will invent new uses for insecticides and new ways to use them, but it seems that insects will always be found to continue to live unharmed. Darwin himself probably could not have found a better example of natural selection than the process of resistance.The many insects born into a primitive population will vary widely in body structure, movement, and physiology, and only the "hardy" insects will be able to resist chemical prescriptions and survive. Spraying kills the weak, and only those insects that have some natural trait that enables them to escape poison remain.The new generation they breed will be endowed with innate "tenacity" in their innate resistance by means of simple heredity.This situation inevitably had the result that intensified spraying with harsh chemicals only made the problem which was originally intended to be solved worse.After a few generations, a single insect population of hardy, resistant species replaces a mixed population of strong and weak. The methods by which insects resist chemicals are likely to be changing and still largely unknown.It has been suggested that some insects are immune to chemical sprays due to favorable body structure, however, there appears to be little actual evidence in this regard.The immunity possessed by some insect species is, however, evident from the observations made by Dr. Blige, who reported the observation of large numbers of flies "in the house at Frolicking in the DDT, like the old wizards danced on the red-hot coals." Similar reports came from other parts of the world.In Kuala Mupo, Malaya, mosquitoes developed resistance to DDT for the first time in non-sprayed central areas.When drug resistance develops, mosquitoes can be found resting on the surface of the stockpiled DDT, and they can be clearly seen at close range with a flashlight.Also, a sample of resistant bedbugs found in a barracks in southern Taiwan had DDT on them at the time.In the laboratory, these bed bugs were wrapped in a cloth filled with DDT, and they lived for a month; they laid eggs; and the baby bed bugs that were born grew and gained weight. That said, insect resistance doesn't necessarily depend on a particular body structure.DDT-resistant flies have an enzyme that allows the flies to degrade DDT into the less toxic chemical DDE.The enzyme is only produced in flies that have a genetic predisposition for DDT resistance.Of course, this resistance factor is hereditary.How flies and other insects detoxify organophosphate chemicals is not well understood. Some activity habits can also keep insects from coming into contact with chemicals.Many workers noticed that resistant flies preferred to settle on unsprayed floors rather than treated walls.Resistant houseflies may have a steady flight habit, always landing in the same place, which greatly reduces the number of exposures to residual poisons.Some malarial ants have a habit of minimizing their exposure to DDT, so that they are virtually immune to poisoning; stimulated by the spray, they fly out of the tent and survive outside. Typically, it takes two to three years for insects to develop resistance, although occasionally resistance develops in as little as a season or even less.At the other extreme, it could take as long as six years.The number of generations an insect reproduces in a year is important and varies with species and climate.For example, Canadian flies develop resistance somewhat more slowly than flies in the southern United States, where the long, hot summers allow the insects to reproduce at high rates. A hopeful question is sometimes asked: "If insects can become resistant to chemical poisons, why can't humans also become resistant?" In theory, humans are also possible; The process of resistance takes hundreds or even thousands of years, so the living people don't have to place any hope on human resistance.Drug resistance is not something that arises in individual organisms.If a person is born with some traits that make him less poisoned than others, then he is more likely to survive and reproduce.Resistance is thus something that develops over many generations in a population.Human populations reproduce at a rate of roughly three generations per century, whereas insects produce new generations in days or weeks. "Should we endure the damage insects do to us, or shall we continue to use various methods of extermination in order to temporarily avoid harm? In some cases, I think, the former is much wiser than the latter. "This is the advice Dr. Brigi gave when he was a director of the Plant Protection Service in the Netherlands: "The advice derived from practice is 'spray as little as possible', not 'spray as much as possible'... applied to pests The spray pressure on the population should always be as low as possible." Unfortunately, such perceptions have not prevailed in the corresponding US Agricultural Service.The Department of Agriculture's 1952 yearbook devoted to insects acknowledged the fact that insects were developing resistance, but added: "More frequent and greater application of insecticides is still required for adequate control of insects." The Department of Agriculture did not Tell what would happen if those untried chemicals could wipe out not only the insects in the world, but all life in the world.But by 1959, just ten years after that advice was repeated, a Connecticut entomologist reported in the Journal of Agricultural and Food Chemistry that the last available new drug had at least one or two effects on the Pests have used it. Dr Brigi said: "It is clearer that we are on a dangerous path. ... We have to be prepared to do a lot of research on other controls, and these new methods will necessarily be biological, not chemical. .Our intention is to direct the course of natural change as carefully as possible in the direction we are heading, without resorting to violence...'. "We need a more intellectual approach and a bigger vision, and that's what I don't see in many researchers. Life is a miracle beyond our ability to comprehend, even before we have to deal with it. We still need to respect it when we struggle... Relying on weapons like pesticides to destroy insects is enough evidence of our lack of knowledge and capacity to control the natural process of change, so the use of violence is useless. Here, what is needed scientifically is With modesty and prudence, there is no reason to be complacent."