Desert locust
Encyclopedia
Plagues of the desert locust (Schistocerca gregaria) have threatened agricultural
production in Africa
, the Middle East
, and Asia
for centuries. The livelihood of at least one-tenth of the world’s human population can be affected by this voracious insect. The desert locust is potentially the most dangerous of the locust
pests because of the ability of swarms to fly rapidly across great distances. It has two to five generations per year. The last major desert locust upsurge in 2004-05 caused significant crop
losses in West Africa
and had a negative impact on food security
in the region. While the desert locust alone is not responsible for famines, it can be an important contributing factor.
When vegetation is distributed in such a way that the nymph
s, usually called hoppers, have to congregate to feed, and there has been sufficient rain for most eggs to hatch, the close physical contact causes the insects' hind legs to bump against one another. This stimulus
triggers a cascade of metabolic and behavioral changes that cause the insects to transform from the solitary form to the gregarious form. When the hoppers become gregarious, they change from green-coloured to yellow and black, and the adults change from brown to red (immature) or yellow (mature). Their bodies become shorter, and they give off a pheromone
that causes them to be attracted to each other, enhancing hopper band and subsequently swarm
formation. Interestingly, the nymphal pheromone is different from the adult one. When exposed to the adult pheromone, hoppers become confused and disoriented, because they can apparently no longer "smell" each other, though the visual and tactile stimuli remain. After a few days, the hopper bands disintegrate and those that escape predation become solitary again. It is possible that this effect could aid locust control in the future.
During quiet periods, called recessions, desert locusts are confined to a 16-million-square-kilometer belt that extends from Mauritania
through the Sahara Desert in northern Africa, across the Arabian Peninsula
, and into northwest India
. Under optimal ecological and climatic conditions, several successive generations can occur, causing swarms to form and invade countries on all sides of the recession area, as far north as Spain
and Russia
, as far south as Nigeria
and Kenya
, and as far east as India
and southwest Asia
. As many as 60 countries can be affected within an area of 32 million square kilometers, or approximately 20 percent of the Earth's land surface.
Locust swarms fly with the wind at roughly the speed of the wind. They can cover from 100 to 200 kilometers in a day, and will fly up to about 2,000 meters above sea level (thereafter, it becomes too cold). Therefore, swarms cannot cross tall mountain ranges such as the Atlas Mountains
, the Hindu Kush
or the Himalayas
. They will not venture into the rain forests of Africa nor into central Europe. However, locust adults and swarms regularly cross the Red Sea
between Africa and the Arabian Peninsula, and are even reported to have crossed the Atlantic Ocean
from Africa
to the Caribbean
in ten days during the 1987-89 plague. A single swarm can cover up to 1200 square kilometers and can contain between 40 and 80 million locusts per square kilometer. The locust can live between three to six months, and there is a ten to 16-fold increase in locust numbers from one generation to the next.
, flower
s, bark
, stems
, fruit
, and seed
s. Nearly all crops, and noncrop plants, are at risk, including pearl millet
, rice
, maize
, sorghum
, sugarcane
, barley
, cotton
, fruit trees, date palm
, vegetables, rangeland grasses, acacia, pine
s, and banana
. What is more, locust droppings are toxic, and spoil any stored food that is left uneaten.
Crop loss from locusts was noted in the Bible
and Qur'an
; these insects have been documented as contributing to the severity of a number of Ethiopian famines. During the twentieth century, desert locust plagues occurred in 1926-1934, 1940–1948, 1949–1963, 1967–1969, 1987–1989 and 2003-2005. The significant crop loss caused by swarming desert locusts exacerbates problems of food shortage, and is a threat to food security
.
's Desert Locust Information Service (DLIS) in Rome, Italy monitors the weather, ecological conditions and the locust situation on a daily basis. DLIS receives results of survey and control operations carried out by national teams in affected countries, and combines this information with satellite
data such as MODIS
, rainfall estimates and seasonal temperature and rainfall predictions to assess the current situation and forecast the timing, scale and location of breeding and migration up to six weeks in advance. The situation assessments and forecasts are published in monthly locust bulletins that date back to the 1970s. These are supplemented by warnings and alerts to affected countries and the international community. Those since the 1990s are available on the FAO Locust Watch web site [www.fao.org/ag/locusts]. FAO also provides information and training to affected countries and coordinates funding from donor agencies in case of major upsurges and plagues.
The desert locust is a difficult pest to control, and control measures are further compounded by the large and often remote areas (16-30 million km²) where locusts can be found. Undeveloped basic infrastructure
in some affected countries, limited resources for locust monitoring and control, and political turmoil within and between affected countries further reduce the capacity of a country to undertake the necessary monitoring and control activities.
At present, the primary method of controlling desert locust infestations is with insecticides applied in small concentrated doses by vehicle-mounted and aerial sprayers at ultra-low volume
(ULV) rates of application. The insecticide is acquired by the insect directly or via secondary pickup (i.e. walking over or eating the residue on a plant). Control is undertaken by government
agencies in locust-affected countries or by specialised organisations such as the Desert Locust Control Organisation for East Africa (DLCO-EA).
Natural enemies such as predatory and parasitic wasp
s and flies, predatory beetle larvae, birds, and reptiles may have limited effects on desert locusts because they can be easily overwhelmed by the sheer magnitude of most swarms and hopper bands. On the other hand, they may be effective in keeping solitary populations in check.
Farmers often try mechanical means of killing locusts, such as digging trenches and burying hopper bands, but this is very labor intensive and is difficult to undertake when large infestations are scattered over a wide area. Farmers also try to scare locust swarms away from their fields by making noise, burning tires or other methods. This tends to shift the problem to neighbouring farms, and locust swarms can easily reinfest previous fields.
extract and pheromones. The effectiveness of many biopesticides equals that of conventional chemical pesticides, but there are two distinct differences. Biopesticides in general take longer to kill insects, plant diseases, or weeds, usually between 2 and 10 days.
There are two types of biopesticides - biochemical and microbial. Biochemical pesticides are similar to naturally occurring chemicals and are nontoxic, such as insect pheromones used to locate mates, while microbial biopesticides like Green Muscle come from bacteria, fungi, algae or viruses that either occur naturally or are genetically altered. Entomopathogenic fungi generally suppress pests by mycosis: causing a disease that is specific
to the insect.
A biological control product has been under development since the late nineties. It is based on a naturally occurring entomopathogenic fungus
(i.e. insects-infecting fungus) , Metarhizium acridum
. Species of Metarhizium are widespread throughout the world, infecting many groups of insects, but show a low risk to humans, other mammal
s and birds. The species M. acridum has specialised on short-horned grasshoppers, to which group locusts belong, and has therefore been chosen as the active ingredient of the product.
The product is available in Africa under the name Green Muscle and in Australia as Green Guard. It is applied in the same way as chemical insecticides, but does not kill as quickly. At recommended doses, the fungus can take up two weeks to kill up to 90% of the locusts. For that reason, it is recommended for use mainly against hoppers, the wingless early stages of locusts. These are mostly found in the desert, far from cropping areas, where the delay in death does not result in damage. The advantage of the product is that it affects only grasshoppers and locusts, which makes it much safer than chemical insecticides. Specifically, it allows the natural enemies of locusts and grasshoppers to continue their beneficial work. These include birds, parasitoid
and predatory wasp
s, parasitoid flies
and certain species of beetle
s. Though natural enemies cannot prevent plagues, they can limit the frequency of outbreaks and contribute to their control. Biopesticides are also safer to use in environmentally sensitive areas such as national parks or near rivers and other water bodies.
Green Muscle was developed under the LUBILOSA
Programme, which was initiated in 1989 in response to environmental concerns over the heavy use of chemical insecticides to control locusts and grasshoppers during the 1987-89 plague. The project focused on the use of beneficial disease-causing microorganism
s (pathogen
s) as biological control agents for grasshoppers and locusts. These insects were considered to be too mobile and to reproduce too fast to be readily controlled by classical biological control. Pathogens have the advantage that many can be produced in artificial culture in large quantities and be used with ordinary spraying equipment. Entomopathogenic fungi were traditionally seen as needing humid conditions to work well. However, the LUBILOSA Programme found a way to avoid this by spraying
fungal spores in an oil formulation
. Even under desert conditions, Green Muscle can be used to kill locusts and other Acridid
pests, such as the Senegalese grasshopper
. During recent trials in Algeria and Mauritania (2005 and 2006), various natural enemies, but especially birds, were abundant enough to eliminate treated hopper bands in about a week, because the diseased hoppers became sluggish and easy to catch.
faced the largest desert locust outbreak in 15 years. The upsurge started as small independent outbreaks that developed in Mauritania, Mali, Niger and Sudan in the autumn of 2003. Two days of unusually heavy rains that stretched from Dakar, Senegal
to Morocco
in October allowed breeding conditions to remain favourable for the next six months and the desert locusts rapidly increased. Lack of rain and cold temperatures in the winter breeding area of northwest Africa in early 2005 slowed the development of the locusts and allowed the locust control agencies to stop the cycle. During the upsurge, nearly 130,000 km² were treated by ground and aerial operations in more than 20 countries. The costs of fighting this upsurge have been estimated by the FAO
to have exceeded US$400 million, and harvest losses were valued at up to US$2.5 billion, which had disastrous effects on the food security
situation in West Africa.
The countries affected by the 2004 outbreak were Algeria
, Burkina Faso
, the Canary Islands
, Cape Verde
, Chad
, Egypt
, Ethiopia
, the Gambia
, Greece
, Guinea
, Guinea Bissau, Israel
, Jordan
, Lebanon
, Libyan Arab Jamahiriya, Mali
, Mauritania
, Morocco
, Niger
, Saudi Arabia
, Senegal
, Sudan
, Syria
and Tunisia
.
and The Bible.
Agriculture
Agriculture is the cultivation of animals, plants, fungi and other life forms for food, fiber, and other products used to sustain life. Agriculture was the key implement in the rise of sedentary human civilization, whereby farming of domesticated species created food surpluses that nurtured the...
production in Africa
Africa
Africa is the world's second largest and second most populous continent, after Asia. At about 30.2 million km² including adjacent islands, it covers 6% of the Earth's total surface area and 20.4% of the total land area...
, the Middle East
Middle East
The Middle East is a region that encompasses Western Asia and Northern Africa. It is often used as a synonym for Near East, in opposition to Far East...
, and Asia
Asia
Asia is the world's largest and most populous continent, located primarily in the eastern and northern hemispheres. It covers 8.7% of the Earth's total surface area and with approximately 3.879 billion people, it hosts 60% of the world's current human population...
for centuries. The livelihood of at least one-tenth of the world’s human population can be affected by this voracious insect. The desert locust is potentially the most dangerous of the locust
Locust
Locusts are the swarming phase of short-horned grasshoppers of the family Acrididae. These are species that can breed rapidly under suitable conditions and subsequently become gregarious and migratory...
pests because of the ability of swarms to fly rapidly across great distances. It has two to five generations per year. The last major desert locust upsurge in 2004-05 caused significant crop
Agriculture
Agriculture is the cultivation of animals, plants, fungi and other life forms for food, fiber, and other products used to sustain life. Agriculture was the key implement in the rise of sedentary human civilization, whereby farming of domesticated species created food surpluses that nurtured the...
losses in West Africa
West Africa
West Africa or Western Africa is the westernmost region of the African continent. Geopolitically, the UN definition of Western Africa includes the following 16 countries and an area of approximately 5 million square km:-Flags of West Africa:...
and had a negative impact on food security
Food security
Food security refers to the availability of food and one's access to it. A household is considered food-secure when its occupants do not live in hunger or fear of starvation. According to the World Resources Institute, global per capita food production has been increasing substantially for the past...
in the region. While the desert locust alone is not responsible for famines, it can be an important contributing factor.
Desert locust ecology
The desert locust lives a solitary life until it rains. Rain causes vegetation growth and allows the female to lay eggs in the sandy soil. The new vegetation provides food for the newly hatched locusts and provides them with shelter as they develop into winged adults.Nymph (biology)
In biology, a nymph is the immature form of some invertebrates, particularly insects, which undergoes gradual metamorphosis before reaching its adult stage. Unlike a typical larva, a nymph's overall form already resembles that of the adult. In addition, while a nymph moults it never enters a...
s, usually called hoppers, have to congregate to feed, and there has been sufficient rain for most eggs to hatch, the close physical contact causes the insects' hind legs to bump against one another. This stimulus
Stimulus (physiology)
In physiology, a stimulus is a detectable change in the internal or external environment. The ability of an organism or organ to respond to external stimuli is called sensitivity....
triggers a cascade of metabolic and behavioral changes that cause the insects to transform from the solitary form to the gregarious form. When the hoppers become gregarious, they change from green-coloured to yellow and black, and the adults change from brown to red (immature) or yellow (mature). Their bodies become shorter, and they give off a pheromone
Pheromone
A pheromone is a secreted or excreted chemical factor that triggers a social response in members of the same species. Pheromones are chemicals capable of acting outside the body of the secreting individual to impact the behavior of the receiving individual...
that causes them to be attracted to each other, enhancing hopper band and subsequently swarm
Swarm
Swarm behaviour, or swarming, is a collective behaviour exhibited by animals of similar size which aggregate together, perhaps milling about the same spot or perhaps moving en masse or migrating in some direction. As a term, swarming is applied particularly to insects, but can also be applied to...
formation. Interestingly, the nymphal pheromone is different from the adult one. When exposed to the adult pheromone, hoppers become confused and disoriented, because they can apparently no longer "smell" each other, though the visual and tactile stimuli remain. After a few days, the hopper bands disintegrate and those that escape predation become solitary again. It is possible that this effect could aid locust control in the future.
During quiet periods, called recessions, desert locusts are confined to a 16-million-square-kilometer belt that extends from Mauritania
Mauritania
Mauritania is a country in the Maghreb and West Africa. It is bordered by the Atlantic Ocean in the west, by Western Sahara in the north, by Algeria in the northeast, by Mali in the east and southeast, and by Senegal in the southwest...
through the Sahara Desert in northern Africa, across the Arabian Peninsula
Arabian Peninsula
The Arabian Peninsula is a land mass situated north-east of Africa. Also known as Arabia or the Arabian subcontinent, it is the world's largest peninsula and covers 3,237,500 km2...
, and into northwest India
India
India , officially the Republic of India , is a country in South Asia. It is the seventh-largest country by geographical area, the second-most populous country with over 1.2 billion people, and the most populous democracy in the world...
. Under optimal ecological and climatic conditions, several successive generations can occur, causing swarms to form and invade countries on all sides of the recession area, as far north as Spain
Spain
Spain , officially the Kingdom of Spain languages]] under the European Charter for Regional or Minority Languages. In each of these, Spain's official name is as follows:;;;;;;), is a country and member state of the European Union located in southwestern Europe on the Iberian Peninsula...
and Russia
Russia
Russia or , officially known as both Russia and the Russian Federation , is a country in northern Eurasia. It is a federal semi-presidential republic, comprising 83 federal subjects...
, as far south as Nigeria
Nigeria
Nigeria , officially the Federal Republic of Nigeria, is a federal constitutional republic comprising 36 states and its Federal Capital Territory, Abuja. The country is located in West Africa and shares land borders with the Republic of Benin in the west, Chad and Cameroon in the east, and Niger in...
and Kenya
Kenya
Kenya , officially known as the Republic of Kenya, is a country in East Africa that lies on the equator, with the Indian Ocean to its south-east...
, and as far east as India
India
India , officially the Republic of India , is a country in South Asia. It is the seventh-largest country by geographical area, the second-most populous country with over 1.2 billion people, and the most populous democracy in the world...
and southwest Asia
Asia
Asia is the world's largest and most populous continent, located primarily in the eastern and northern hemispheres. It covers 8.7% of the Earth's total surface area and with approximately 3.879 billion people, it hosts 60% of the world's current human population...
. As many as 60 countries can be affected within an area of 32 million square kilometers, or approximately 20 percent of the Earth's land surface.
Atlas Mountains
The Atlas Mountains is a mountain range across a northern stretch of Africa extending about through Morocco, Algeria, and Tunisia. The highest peak is Toubkal, with an elevation of in southwestern Morocco. The Atlas ranges separate the Mediterranean and Atlantic coastlines from the Sahara Desert...
, the Hindu Kush
Hindu Kush
The Hindu Kush is an mountain range that stretches between central Afghanistan and northern Pakistan. The highest point in the Hindu Kush is Tirich Mir in the Chitral region of Khyber-Pakhtunkhwa, Pakistan.It is the westernmost extension of the Pamir Mountains, the Karakoram Range, and is a...
or the Himalayas
Himalayas
The Himalaya Range or Himalaya Mountains Sanskrit: Devanagari: हिमालय, literally "abode of snow"), usually called the Himalayas or Himalaya for short, is a mountain range in Asia, separating the Indian subcontinent from the Tibetan Plateau...
. They will not venture into the rain forests of Africa nor into central Europe. However, locust adults and swarms regularly cross the Red Sea
Red Sea
The Red Sea is a seawater inlet of the Indian Ocean, lying between Africa and Asia. The connection to the ocean is in the south through the Bab el Mandeb strait and the Gulf of Aden. In the north, there is the Sinai Peninsula, the Gulf of Aqaba, and the Gulf of Suez...
between Africa and the Arabian Peninsula, and are even reported to have crossed the Atlantic Ocean
Atlantic Ocean
The Atlantic Ocean is the second-largest of the world's oceanic divisions. With a total area of about , it covers approximately 20% of the Earth's surface and about 26% of its water surface area...
from Africa
Africa
Africa is the world's second largest and second most populous continent, after Asia. At about 30.2 million km² including adjacent islands, it covers 6% of the Earth's total surface area and 20.4% of the total land area...
to the Caribbean
Caribbean
The Caribbean is a crescent-shaped group of islands more than 2,000 miles long separating the Gulf of Mexico and the Caribbean Sea, to the west and south, from the Atlantic Ocean, to the east and north...
in ten days during the 1987-89 plague. A single swarm can cover up to 1200 square kilometers and can contain between 40 and 80 million locusts per square kilometer. The locust can live between three to six months, and there is a ten to 16-fold increase in locust numbers from one generation to the next.
Locust swarming
The migratory locust (Locusta migratoria) ranges from Europe to China, and even small swarms may cover several square miles, and weigh thousands of tons. Control by spreading poisoned food among the bands is very effective, but it is cheapest to spray concentrated insecticide solutions from aircraft over the insects or the vegetation on which they feed. They eat the equivalent of their own weight in a day, and, flying at night with the wind, may cover some 500 km/300 mi. The largest known swarm covered 1,036 km2/400 sq mi, comprising approximately 40 billion insects.Crop loss
Desert locusts can consume the approximate equivalent of their body mass each day (2 g) in green vegetation: leavesLeaves
-History:Vocalist Arnar Gudjonsson was formerly the guitarist with Mower, and he was joined by Hallur Hallsson , Arnar Ólafsson , Bjarni Grímsson , and Andri Ásgrímsson . Late in 2001 they played with Emiliana Torrini and drew early praise from the New York Times...
, flower
Flower
A flower, sometimes known as a bloom or blossom, is the reproductive structure found in flowering plants . The biological function of a flower is to effect reproduction, usually by providing a mechanism for the union of sperm with eggs...
s, bark
Bark
Bark is the outermost layers of stems and roots of woody plants. Plants with bark include trees, woody vines and shrubs. Bark refers to all the tissues outside of the vascular cambium and is a nontechnical term. It overlays the wood and consists of the inner bark and the outer bark. The inner...
, stems
Plant stem
A stem is one of two main structural axes of a vascular plant. The stem is normally divided into nodes and internodes, the nodes hold buds which grow into one or more leaves, inflorescence , conifer cones, roots, other stems etc. The internodes distance one node from another...
, fruit
Fruit
In broad terms, a fruit is a structure of a plant that contains its seeds.The term has different meanings dependent on context. In non-technical usage, such as food preparation, fruit normally means the fleshy seed-associated structures of certain plants that are sweet and edible in the raw state,...
, and seed
Seed
A seed is a small embryonic plant enclosed in a covering called the seed coat, usually with some stored food. It is the product of the ripened ovule of gymnosperm and angiosperm plants which occurs after fertilization and some growth within the mother plant...
s. Nearly all crops, and noncrop plants, are at risk, including pearl millet
Pearl millet
Pearl millet is the most widely grown type of millet. Grown in Africa and the Indian subcontinent since prehistoric times, it is generally accepted that pearl millet originated in Africa and was subsequently introduced into India. The center of diversity, and suggested area of domestication, for...
, rice
Rice
Rice is the seed of the monocot plants Oryza sativa or Oryza glaberrima . As a cereal grain, it is the most important staple food for a large part of the world's human population, especially in East Asia, Southeast Asia, South Asia, the Middle East, and the West Indies...
, maize
Maize
Maize known in many English-speaking countries as corn or mielie/mealie, is a grain domesticated by indigenous peoples in Mesoamerica in prehistoric times. The leafy stalk produces ears which contain seeds called kernels. Though technically a grain, maize kernels are used in cooking as a vegetable...
, sorghum
Sorghum
Sorghum is a genus of numerous species of grasses, one of which is raised for grain and many of which are used as fodder plants either cultivated or as part of pasture. The plants are cultivated in warmer climates worldwide. Species are native to tropical and subtropical regions of all continents...
, sugarcane
Sugarcane
Sugarcane refers to any of six to 37 species of tall perennial grasses of the genus Saccharum . Native to the warm temperate to tropical regions of South Asia, they have stout, jointed, fibrous stalks that are rich in sugar, and measure two to six metres tall...
, barley
Barley
Barley is a major cereal grain, a member of the grass family. It serves as a major animal fodder, as a base malt for beer and certain distilled beverages, and as a component of various health foods...
, cotton
Cotton
Cotton is a soft, fluffy staple fiber that grows in a boll, or protective capsule, around the seeds of cotton plants of the genus Gossypium. The fiber is almost pure cellulose. The botanical purpose of cotton fiber is to aid in seed dispersal....
, fruit trees, date palm
Date Palm
The date palm is a palm in the genus Phoenix, cultivated for its edible sweet fruit. Although its place of origin is unknown because of long cultivation, it probably originated from lands around the Persian Gulf. It is a medium-sized plant, 15–25 m tall, growing singly or forming a clump with...
, vegetables, rangeland grasses, acacia, pine
Pine
Pines are trees in the genus Pinus ,in the family Pinaceae. They make up the monotypic subfamily Pinoideae. There are about 115 species of pine, although different authorities accept between 105 and 125 species.-Etymology:...
s, and banana
Banana
Banana is the common name for herbaceous plants of the genus Musa and for the fruit they produce. Bananas come in a variety of sizes and colors when ripe, including yellow, purple, and red....
. What is more, locust droppings are toxic, and spoil any stored food that is left uneaten.
Bible
The Bible refers to any one of the collections of the primary religious texts of Judaism and Christianity. There is no common version of the Bible, as the individual books , their contents and their order vary among denominations...
and Qur'an
Qur'an
The Quran , also transliterated Qur'an, Koran, Alcoran, Qur’ān, Coran, Kuran, and al-Qur’ān, is the central religious text of Islam, which Muslims consider the verbatim word of God . It is regarded widely as the finest piece of literature in the Arabic language...
; these insects have been documented as contributing to the severity of a number of Ethiopian famines. During the twentieth century, desert locust plagues occurred in 1926-1934, 1940–1948, 1949–1963, 1967–1969, 1987–1989 and 2003-2005. The significant crop loss caused by swarming desert locusts exacerbates problems of food shortage, and is a threat to food security
Food security
Food security refers to the availability of food and one's access to it. A household is considered food-secure when its occupants do not live in hunger or fear of starvation. According to the World Resources Institute, global per capita food production has been increasing substantially for the past...
.
Control
Early warning and preventive control is the strategy adopted by locust-affected countries in Africa and Asia to try to stop locust plagues from developing and spreading. FAOFão
Fão is a town in Esposende Municipality in Portugal....
's Desert Locust Information Service (DLIS) in Rome, Italy monitors the weather, ecological conditions and the locust situation on a daily basis. DLIS receives results of survey and control operations carried out by national teams in affected countries, and combines this information with satellite
Satellite
In the context of spaceflight, a satellite is an object which has been placed into orbit by human endeavour. Such objects are sometimes called artificial satellites to distinguish them from natural satellites such as the Moon....
data such as MODIS
MODIS
The Moderate-resolution Imaging Spectroradiometer is a payload scientific instrument launched into Earth orbit by NASA in 1999 on board the Terra Satellite, and in 2002 on board the Aqua satellite...
, rainfall estimates and seasonal temperature and rainfall predictions to assess the current situation and forecast the timing, scale and location of breeding and migration up to six weeks in advance. The situation assessments and forecasts are published in monthly locust bulletins that date back to the 1970s. These are supplemented by warnings and alerts to affected countries and the international community. Those since the 1990s are available on the FAO Locust Watch web site [www.fao.org/ag/locusts]. FAO also provides information and training to affected countries and coordinates funding from donor agencies in case of major upsurges and plagues.
The desert locust is a difficult pest to control, and control measures are further compounded by the large and often remote areas (16-30 million km²) where locusts can be found. Undeveloped basic infrastructure
Infrastructure
Infrastructure is basic physical and organizational structures needed for the operation of a society or enterprise, or the services and facilities necessary for an economy to function...
in some affected countries, limited resources for locust monitoring and control, and political turmoil within and between affected countries further reduce the capacity of a country to undertake the necessary monitoring and control activities.
At present, the primary method of controlling desert locust infestations is with insecticides applied in small concentrated doses by vehicle-mounted and aerial sprayers at ultra-low volume
Ultra-low volume
The term Ultra-Low Volume is used in the context of pesticide application.Ultra-low volume application of pesticides has been defined as spraying at a of les than 5 L/ha for field crops or les than 50 L/ha for tree/bush crops...
(ULV) rates of application. The insecticide is acquired by the insect directly or via secondary pickup (i.e. walking over or eating the residue on a plant). Control is undertaken by government
Government
Government refers to the legislators, administrators, and arbitrators in the administrative bureaucracy who control a state at a given time, and to the system of government by which they are organized...
agencies in locust-affected countries or by specialised organisations such as the Desert Locust Control Organisation for East Africa (DLCO-EA).
Natural enemies such as predatory and parasitic wasp
Parasitic wasp
The term parasitoid wasp refers to a large evolutionary grade of hymenopteran superfamilies, mainly in the Apocrita. They are primarily parasitoids of other animals, mostly other arthropods...
s and flies, predatory beetle larvae, birds, and reptiles may have limited effects on desert locusts because they can be easily overwhelmed by the sheer magnitude of most swarms and hopper bands. On the other hand, they may be effective in keeping solitary populations in check.
Farmers often try mechanical means of killing locusts, such as digging trenches and burying hopper bands, but this is very labor intensive and is difficult to undertake when large infestations are scattered over a wide area. Farmers also try to scare locust swarms away from their fields by making noise, burning tires or other methods. This tends to shift the problem to neighbouring farms, and locust swarms can easily reinfest previous fields.
Biopesticides
Biopesticides include fungi, bacteria, neemNeem
Azadirachta indica is a tree in the mahogany family Meliaceae. It is one of two species in the genus Azadirachta, and is native to India growing in tropical and semi-tropical regions. Its fruits and seeds are the source of neem oil...
extract and pheromones. The effectiveness of many biopesticides equals that of conventional chemical pesticides, but there are two distinct differences. Biopesticides in general take longer to kill insects, plant diseases, or weeds, usually between 2 and 10 days.
There are two types of biopesticides - biochemical and microbial. Biochemical pesticides are similar to naturally occurring chemicals and are nontoxic, such as insect pheromones used to locate mates, while microbial biopesticides like Green Muscle come from bacteria, fungi, algae or viruses that either occur naturally or are genetically altered. Entomopathogenic fungi generally suppress pests by mycosis: causing a disease that is specific
Specific
Specific may refer to:* Specificity* Specific, a cure or therapy for a specific illnessLaw:* Specific deterrence, focussed on an individual* Specific finding, intermediate verdict used by a jury in determining the final verdict...
to the insect.
A biological control product has been under development since the late nineties. It is based on a naturally occurring entomopathogenic fungus
Entomopathogenic fungus
An entomopathogenic fungus is a fungus that can act as a parasite of insects and kills or seriously disables them.-Typical life cycle:These fungi usually attach to the external body surface of insects in the form of microscopic spores...
(i.e. insects-infecting fungus) , Metarhizium acridum
Metarhizium acridum
Metarhizium acridum is the new name given to a group of fungal isolates that are known to be virulent and specific to Acrididea. Previously, this species has had variety status in Metarhizium anisopliae and before that, reference was made to M. flavoviride.- Biology :M...
. Species of Metarhizium are widespread throughout the world, infecting many groups of insects, but show a low risk to humans, other mammal
Mammal
Mammals are members of a class of air-breathing vertebrate animals characterised by the possession of endothermy, hair, three middle ear bones, and mammary glands functional in mothers with young...
s and birds. The species M. acridum has specialised on short-horned grasshoppers, to which group locusts belong, and has therefore been chosen as the active ingredient of the product.
The product is available in Africa under the name Green Muscle and in Australia as Green Guard. It is applied in the same way as chemical insecticides, but does not kill as quickly. At recommended doses, the fungus can take up two weeks to kill up to 90% of the locusts. For that reason, it is recommended for use mainly against hoppers, the wingless early stages of locusts. These are mostly found in the desert, far from cropping areas, where the delay in death does not result in damage. The advantage of the product is that it affects only grasshoppers and locusts, which makes it much safer than chemical insecticides. Specifically, it allows the natural enemies of locusts and grasshoppers to continue their beneficial work. These include birds, parasitoid
Parasitoid
A parasitoid is an organism that spends a significant portion of its life history attached to or within a single host organism in a relationship that is in essence parasitic; unlike a true parasite, however, it ultimately sterilises or kills, and sometimes consumes, the host...
and predatory wasp
Wasp
The term wasp is typically defined as any insect of the order Hymenoptera and suborder Apocrita that is neither a bee nor an ant. Almost every pest insect species has at least one wasp species that preys upon it or parasitizes it, making wasps critically important in natural control of their...
s, parasitoid flies
Fly
True flies are insects of the order Diptera . They possess a pair of wings on the mesothorax and a pair of halteres, derived from the hind wings, on the metathorax...
and certain species of beetle
Beetle
Coleoptera is an order of insects commonly called beetles. The word "coleoptera" is from the Greek , koleos, "sheath"; and , pteron, "wing", thus "sheathed wing". Coleoptera contains more species than any other order, constituting almost 25% of all known life-forms...
s. Though natural enemies cannot prevent plagues, they can limit the frequency of outbreaks and contribute to their control. Biopesticides are also safer to use in environmentally sensitive areas such as national parks or near rivers and other water bodies.
Green Muscle was developed under the LUBILOSA
LUBILOSA
LUBILOSA was the name of a research programme that aimed at developing a biological alternative to the chemical control of locusts. This name is an acronym of the French title of the programme: Lutte Biologique contre les Locustes et les Sauteriaux...
Programme, which was initiated in 1989 in response to environmental concerns over the heavy use of chemical insecticides to control locusts and grasshoppers during the 1987-89 plague. The project focused on the use of beneficial disease-causing microorganism
Microorganism
A microorganism or microbe is a microscopic organism that comprises either a single cell , cell clusters, or no cell at all...
s (pathogen
Pathogen
A pathogen gignomai "I give birth to") or infectious agent — colloquially, a germ — is a microbe or microorganism such as a virus, bacterium, prion, or fungus that causes disease in its animal or plant host...
s) as biological control agents for grasshoppers and locusts. These insects were considered to be too mobile and to reproduce too fast to be readily controlled by classical biological control. Pathogens have the advantage that many can be produced in artificial culture in large quantities and be used with ordinary spraying equipment. Entomopathogenic fungi were traditionally seen as needing humid conditions to work well. However, the LUBILOSA Programme found a way to avoid this by spraying
Pesticide application
Pesticide application refers to the practical way in which pesticides, are delivered to their biological targets...
fungal spores in an oil formulation
Pesticide formulation
The biological activity of a pesticide, be it chemical or biological in nature, is determined by its active ingredient . Pesticide products very rarely consist of pure technical material. The AI is usually formulated with other materials and this is the product as sold, but it may be further...
. Even under desert conditions, Green Muscle can be used to kill locusts and other Acridid
Acrididae
The Acrididae are the predominant family of grasshoppers, comprising some 10,000 of the 11,000 species of the entire suborder Caelifera. The Acrididae are best known because all locusts are of the Acrididae. The subfamily Oedipodinae is sometimes classified as a distinct family Oedipodidae in the...
pests, such as the Senegalese grasshopper
Senegalese grasshopper
Oedaleus senegalensis is a medium-sized grasshopper species found in the Sahel region of Africa, the Canary Islands, Cape Verde Islands and West Asia. Although not called a locust in English, this species shows gregarious behaviour and some morphological change on crowding...
. During recent trials in Algeria and Mauritania (2005 and 2006), various natural enemies, but especially birds, were abundant enough to eliminate treated hopper bands in about a week, because the diseased hoppers became sluggish and easy to catch.
2003-2005 Desert locust upsurge
From October 2003 to May 2005, West AfricaWest Africa
West Africa or Western Africa is the westernmost region of the African continent. Geopolitically, the UN definition of Western Africa includes the following 16 countries and an area of approximately 5 million square km:-Flags of West Africa:...
faced the largest desert locust outbreak in 15 years. The upsurge started as small independent outbreaks that developed in Mauritania, Mali, Niger and Sudan in the autumn of 2003. Two days of unusually heavy rains that stretched from Dakar, Senegal
Senegal
Senegal , officially the Republic of Senegal , is a country in western Africa. It owes its name to the Sénégal River that borders it to the east and north...
to Morocco
Morocco
Morocco , officially the Kingdom of Morocco , is a country located in North Africa. It has a population of more than 32 million and an area of 710,850 km², and also primarily administers the disputed region of the Western Sahara...
in October allowed breeding conditions to remain favourable for the next six months and the desert locusts rapidly increased. Lack of rain and cold temperatures in the winter breeding area of northwest Africa in early 2005 slowed the development of the locusts and allowed the locust control agencies to stop the cycle. During the upsurge, nearly 130,000 km² were treated by ground and aerial operations in more than 20 countries. The costs of fighting this upsurge have been estimated by the FAO
Fão
Fão is a town in Esposende Municipality in Portugal....
to have exceeded US$400 million, and harvest losses were valued at up to US$2.5 billion, which had disastrous effects on the food security
Food security
Food security refers to the availability of food and one's access to it. A household is considered food-secure when its occupants do not live in hunger or fear of starvation. According to the World Resources Institute, global per capita food production has been increasing substantially for the past...
situation in West Africa.
The countries affected by the 2004 outbreak were Algeria
Algeria
Algeria , officially the People's Democratic Republic of Algeria , also formally referred to as the Democratic and Popular Republic of Algeria, is a country in the Maghreb region of Northwest Africa with Algiers as its capital.In terms of land area, it is the largest country in Africa and the Arab...
, Burkina Faso
Burkina Faso
Burkina Faso – also known by its short-form name Burkina – is a landlocked country in west Africa. It is surrounded by six countries: Mali to the north, Niger to the east, Benin to the southeast, Togo and Ghana to the south, and Côte d'Ivoire to the southwest.Its size is with an estimated...
, the Canary Islands
Canary Islands
The Canary Islands , also known as the Canaries , is a Spanish archipelago located just off the northwest coast of mainland Africa, 100 km west of the border between Morocco and the Western Sahara. The Canaries are a Spanish autonomous community and an outermost region of the European Union...
, Cape Verde
Cape Verde
The Republic of Cape Verde is an island country, spanning an archipelago of 10 islands located in the central Atlantic Ocean, 570 kilometres off the coast of Western Africa...
, Chad
Chad
Chad , officially known as the Republic of Chad, is a landlocked country in Central Africa. It is bordered by Libya to the north, Sudan to the east, the Central African Republic to the south, Cameroon and Nigeria to the southwest, and Niger to the west...
, Egypt
Egypt
Egypt , officially the Arab Republic of Egypt, Arabic: , is a country mainly in North Africa, with the Sinai Peninsula forming a land bridge in Southwest Asia. Egypt is thus a transcontinental country, and a major power in Africa, the Mediterranean Basin, the Middle East and the Muslim world...
, Ethiopia
Ethiopia
Ethiopia , officially known as the Federal Democratic Republic of Ethiopia, is a country located in the Horn of Africa. It is the second-most populous nation in Africa, with over 82 million inhabitants, and the tenth-largest by area, occupying 1,100,000 km2...
, the Gambia
The Gambia
The Republic of The Gambia, commonly referred to as The Gambia, or Gambia , is a country in West Africa. Gambia is the smallest country on mainland Africa, surrounded by Senegal except for a short coastline on the Atlantic Ocean in the west....
, Greece
Greece
Greece , officially the Hellenic Republic , and historically Hellas or the Republic of Greece in English, is a country in southeastern Europe....
, Guinea
Guinea
Guinea , officially the Republic of Guinea , is a country in West Africa. Formerly known as French Guinea , it is today sometimes called Guinea-Conakry to distinguish it from its neighbour Guinea-Bissau. Guinea is divided into eight administrative regions and subdivided into thirty-three prefectures...
, Guinea Bissau, Israel
Israel
The State of Israel is a parliamentary republic located in the Middle East, along the eastern shore of the Mediterranean Sea...
, Jordan
Jordan
Jordan , officially the Hashemite Kingdom of Jordan , Al-Mamlaka al-Urduniyya al-Hashemiyya) is a kingdom on the East Bank of the River Jordan. The country borders Saudi Arabia to the east and south-east, Iraq to the north-east, Syria to the north and the West Bank and Israel to the west, sharing...
, Lebanon
Lebanon
Lebanon , officially the Republic of LebanonRepublic of Lebanon is the most common term used by Lebanese government agencies. The term Lebanese Republic, a literal translation of the official Arabic and French names that is not used in today's world. Arabic is the most common language spoken among...
, Libyan Arab Jamahiriya, Mali
Mali
Mali , officially the Republic of Mali , is a landlocked country in Western Africa. Mali borders Algeria on the north, Niger on the east, Burkina Faso and the Côte d'Ivoire on the south, Guinea on the south-west, and Senegal and Mauritania on the west. Its size is just over 1,240,000 km² with...
, Mauritania
Mauritania
Mauritania is a country in the Maghreb and West Africa. It is bordered by the Atlantic Ocean in the west, by Western Sahara in the north, by Algeria in the northeast, by Mali in the east and southeast, and by Senegal in the southwest...
, Morocco
Morocco
Morocco , officially the Kingdom of Morocco , is a country located in North Africa. It has a population of more than 32 million and an area of 710,850 km², and also primarily administers the disputed region of the Western Sahara...
, Niger
Niger
Niger , officially named the Republic of Niger, is a landlocked country in Western Africa, named after the Niger River. It borders Nigeria and Benin to the south, Burkina Faso and Mali to the west, Algeria and Libya to the north and Chad to the east...
, Saudi Arabia
Saudi Arabia
The Kingdom of Saudi Arabia , commonly known in British English as Saudi Arabia and in Arabic as as-Sa‘ūdiyyah , is the largest state in Western Asia by land area, constituting the bulk of the Arabian Peninsula, and the second-largest in the Arab World...
, Senegal
Senegal
Senegal , officially the Republic of Senegal , is a country in western Africa. It owes its name to the Sénégal River that borders it to the east and north...
, Sudan
Sudan
Sudan , officially the Republic of the Sudan , is a country in North Africa, sometimes considered part of the Middle East politically. It is bordered by Egypt to the north, the Red Sea to the northeast, Eritrea and Ethiopia to the east, South Sudan to the south, the Central African Republic to the...
, Syria
Syria
Syria , officially the Syrian Arab Republic , is a country in Western Asia, bordering Lebanon and the Mediterranean Sea to the West, Turkey to the north, Iraq to the east, Jordan to the south, and Israel to the southwest....
and Tunisia
Tunisia
Tunisia , officially the Tunisian RepublicThe long name of Tunisia in other languages used in the country is: , is the northernmost country in Africa. It is a Maghreb country and is bordered by Algeria to the west, Libya to the southeast, and the Mediterranean Sea to the north and east. Its area...
.
Desert locusts in culture
Owing to the destructive habits of locusts, they have been a representation of famine in many Middle Eastern cultures. This theme commonly occurs, such as in the movies The MummyThe Mummy (1999 film)
The Mummy is a 1999 American adventure film written and directed by Stephen Sommers and starring Brendan Fraser, Rachel Weisz, John Hannah and Kevin J. O'Connor, with Arnold Vosloo in the title role as the reanimated mummy. The film features substantial dialogue in ancient Egyptian language, spoken...
and The Bible.
External links
- FAO Locust Watch site
- Lubilosa site
- Green Muscle Handbook
- Delivery systems
- Why Locusts Swarm: A Study Finds 'Tipping Point'
- Columbia University IRI Climate and Desert Locust
- Desert Locust Meteorological Monitoring, at Sahel Resources
- Cultivation of locusts for the pet trade
Further reading
- Abdin, A. Stein & A. van Huis, 2001. Spatial distribution of the desert locust, Schistocerca gregaria, in the plains of the Red Sea coast of Sudan during the winter of 1999.
- Ceccato, P., K. Cressman, A. Giannini, S. Trzaska. 2007. The desert locust upsurge in West Africa (2003–2005): Information on the desert locust early warning system and the prospects for seasonal climate forecasting. Intl J Pest Management 53(1): 7-13.
- Cressman, K. 1996. Current methods of desert locust forecasting at FAO. Bulletin OEPP/EPPO Bulletin 26: 577-585.
- Cressman, K. 2008. The use of new technologies in Desert Locust early warning. Outlooks on Pest Management (April, 2008): 55-59.
- Symmons, P. & A. van Huis, 1997. Desert Locust Control campaign studies: operations guidebook. Wageningen University. 167 pp. & CD-Rom, 19 floppy disks.
- Van Huis, A. 1994. Desert locust control with existing techniques: an evaluation of strategies. Proceedings of the Seminar held in Wageningen, the Netherlands, 6–11 December 1993. 132 pp. ISBN 90-6754-364-0.
- Van Huis, A. 1995. Desert locust plagues. Endeavour, 19(3): 118-124.
- Van Huis, A. 1997. Can we prevent desert locust plagues? In: New strategies in locust control (Eds.: S. Krall, R. Preveling and D.B. Diallo), pp. 453–459. Birkhäuser Verlag, Basel. 522 pp.
- Van Huis, A., K. Cressman, J. Magor. 2007. Preventing desert locust plagues: optimizing management interventions. Entomologia Experimentalis et Applicata 122: 191-214.
- Werf, W. van der, G. Woldewahid, T. Abate, M. Butrous, O. Abdalla, A.M. Khidir, B. Mustafa, I. Magzoub, O.
- Vallebona C, Genesio L, Crisci A, Pasqui M, Di Vecchia A, Maracchi G (2008). Large-scale climatic patterns forcing desert locust upsurges in West Africa. CLIMATE RESEARCH (2008) 37:35-41. ISSN: 1616-1572. http://www.int-res.com/abstracts/cr/v37/n1/p35-41/