Harmful Effects Of Locust In A World

Pakistan’s example may be useful for India. According to the Food and Agriculture Organization (FAO), locust invasions would continue in India till July and could reach up to Odisha and Bihar with the monsoon winds and return to Rajasthan subsequently.

By : Nargis Naheed¹ Muhammad Dilawaiz Khan² Zunaira Maqsood¹ Iqra Mehmood¹ Zainab Toheed¹

However, the swarms are less likely to reach South India, Nepal, and Bangladesh. An unusually wet late winter season has laid the pathway for the locusts to spread, though a heatwave in central India may provide some relief.

As the biggest locust swarms for more than 25 years threaten India and Pakistan’s breadbasket regions, a pilot project in Pakistan offers a way to cull the crop-destroying pests without using insecticides that harm people and the environment.

• Huge swarms darkened the sky in Jaipur in recent days; one resident of Rajasthan’s biggest city said it was like being “overtaken by aliens,” the New York Times reported. However, the biggest threat is to farmers and poor rural communities already hit hard economically by Covid-19.
• Pakistan’s eastern provinces were first overwhelmed in the winter. Fresh swarms are just beginning to take to the air and are expected to grow until mid-summer. Pakistan’s government approved a National Action Plan for locust control in February and airborne spraying of some 300,000 liters of insecticide is taking place.
• Climate change has played a role in the locust plague. It started after exceptional cyclonic rainfall moistened the “Empty Quarter” deserts of Saudi Arabia in 2019. Biblical quantities of locusts hatched and have been breeding ever since. The swarms were swept eastwards through Iran to Pakistan by seasonal winds. After breeding in Pakistan’s eastern deserts, the locusts took to the air again in late winter. Now, another generation has hatched and crossed into India.

Remedies: A strict round-the-clock vigilance and spraying of pesticides or organophosphate chemicals is a fundamental step to control the locusts. The Locust Warning Organization (LWO) has ordered drones for sprinkling chemicals in order to kill the locust. 

According to their behavior patterns, as locusts settle during the night on trees, that is when pesticides have to be sprayed. India has proposed to Pakistan and Iran for a coordinated approach in dealing with the alarming threat of fast-increasing desert locusts in the region. In the long term, a comprehensive plan to prevent sudden and extreme climate change will be imperative.

What is FAO role in tackling of desert locusts menace?

• The Locusts and Trans-boundary Plant Pests and Diseases Group is responsible for assisting members throughout the world in managing migratory pests, mainly locusts, and diseases through early warning and early reaction.
• The group has three regional commissions for controlling desert locust: 
  • in Northwest and West Africa 
  • in the Near East 
  • in Southwest Asia 
• FAO’s Desert Locust Information Service (DLIS)is the focal point for all locust and locust-related information that is necessary to operate an early warning system for desert locust plagues.
• FAO prepares monthly bulletins and updates summarizing the locust situation and providing six-week forecasts of migration and breeding on a country-by-country basis.
• It undertakes field assessment missions, strengthens national capacity, develops new innovative tools and techniques, coordinates control operations, and emergency assistance during locust upsurges and plagues.
• It has laid out a standard operating procedure (SOP)to deal with locust menace.
• Sandy areas that have green vegetation are to be monitored constantly to see if locusts are present.
• Desert areas receiving rainfall are to be surveyed for live locusts or their eggs.
• Recommended pesticides are to be used to stop their breeding.
• Areas, where farmers have recently reported sighting of locusts, are to be surveyed and sanitized.
• Special attention is to be paid in areas where day temperature ranges between 20 degrees Celsius and 38 degrees Celsius because if these areas have moisture or receive rain, the desert locusts are likely to swarm in.

What is a locust attack?

• Locusts are the oldest migratory pest in the world.
• They differ from ordinary grasshoppers in their ability to change behavior (gregarize) and form swarms that can migrate over large distances. 
• No taxonomic distinction is made between locust and grasshopper species.
• Swarming behavior is a response to overcrowding. 
• The most devastating of all locust species is the Desert Locust (Schistocerca gregaria).
• When desert locusts meet, their nervous systems release serotonin, which causes them to become mutually attracted, a prerequisite for swarming. 
• During quiet periods, Desert Locusts live in the desert areas between West Africa and India.
• Three pests, the Italian Locust, the Moroccan Locust, and the Asian Migratory Locust, jeopardize food security and livelihood in the Caucasus and Central Asia (CCA) as well as in adjacent areas of northern Afghanistan and the southern Russian Federation.
• Locusts have a high capacity to multiply, form groups, migrate over relatively large distances (they can fly up to 150 km per day).
• If ecological conditions become favorable, they rapidly reproduce and increase some 20-fold in three months.
• Initial bands of gregarious hoppers are known as “outbreaks”.
• When these join together into larger groups, the event is known as an “upsurge”.
• Continuing agglomerations of upsurges on a regional level originating from a number of entirely separate breeding locations are known as “plagues”.
• Locusts need moist, sandy soil in which to lay eggs and fresh vegetation for hoppers to grow into adults. 

Locust attack in India and other parts of the World:

Locust swarms are the bane of farmers in more than 66 countries. Locust is the only insect that has a global committee working to outlet it. Although the Sahel (Africa) and the Arabian Peninsula are the major breeding grounds of the desert locust, it is also indigenous to India. 

Swarms migrate according to seasonal rains and the prevailing winds to two widely separated geographic belts – the winter-spring breeding zone and the summer-autumn zone. 

From the deserts of the Sahel and the arid zones along the Red Sea, they grow steadily in numbers and begin to spread across the Arabian Sea. They fly at heights of up to two km and, aided by winds, can cover a distance of 2,000 km at one stretch. 

They eventually land on the shores of the Indian subcontinent, their arrival coinciding with the southwest monsoon. 

There have been a dozen plague cycles in India since 1860. In 1926-31 there was a locust plague in Punjab and Uttar-Pradesh. There were repeated plagues in 1949-55, 1959 and 1978. Although there was an upsurge of locusts in 1988, there was no damage to crops.     

The desert locust plague in Africa, the Middle East, and Asia lasted from 1966 to 1969. The 1985-88 plague in the Sahel and the Arabian Peninsula collapsed suddenly because unusual wind patterns carried swarms heading for Morocco into the Atlantic Ocean, where they perished.

In 2017, an outbreak developed on the central and southern Red Sea coast in Saudi Arabia. During April, 2017 an outbreak developed in the west and northwest Mauritania.

Imminent Danger:

• “Towards the end of May and in June and July, high-level migration is expected,” warns Tariq Khan, director of the Technical Department of Plant Protection in Pakistan’s Sindh province.
• Farmer Ghulam Sarwar Panhwar saw millions of the pests devour his cotton and moringa crops in just a few hours. “This was their second attack this month. With locusts attacking our crops during the day, bats attacking our mango orchards at night and coronavirus attacking us in our home’s day and night, where do we go?” asks Panhwar, who owns two farms totaling 300 acres in the Hyderabad district of Sindh.
• The pesticides used by the government are carcinogenic to humans and poisonous to wildlife, warns Sohail Ahmed, an animal biologist at the University of Agriculture in Peshawar. “No bio-safe pesticide is being used at the moment. These chemical sprays are toxic to the environment and will affect humans, wildlife, and livestock.”
• Farmers in Sindh, Balochistan, and parts of Punjab near Pakistan’s desert regions have already noticed changes. “Already the parrots have died out due to the pesticides used in fruit orchards. I’ve noticed that the crows that used to eat the locusts have stopped coming,” says Panhwar, who fears the impact on the water supply, soil, and crops.

Simple Solution:

• With the locust problem escalating, an innovative pilot project in Pakistan’s Okara district offers a sustainable solution in which farmers earn money by trapping locusts that are turned into high-protein chicken feed by animal feed mills.
• It was the brainchild of Muhammad Khurshid, a civil servant in the Ministry of National Food Security and Research, and Johar Ali, a biotechnologist from the Pakistan Agricultural Research Council.
• “We were mocked for doing this – no one thought that people could actually catch locusts and sell them,” says Ali.
• Khurshid says they were inspired by an example in Yemen in May 2019. The motto in that war-torn country facing famine was, “Eat the locusts before they eat the crop.”
• They selected Okara district, as it is a heavily populated rural area of Pakistan’s Punjab. They set up a three-day trial project in the Pepli Pahar Forest in Depalpur, where huge swarms of adult locusts were reported in mid-February 2020. The forest area was chosen as it was less likely to be contaminated by an insecticide.

• Popular Idea:

• Using the slogan, “Catch locusts. Earn money. Save crops”, the project offered to pay farmers 20 Pakistani rupees (USD 0.12) per kilogram of locusts.
• Locusts only fly in daylight. At night, they cluster on trees and open ground without dense vegetation and remain almost motionless till sunrise the next day. Locusts are easy to catch at night, Khurshid says.
• The community’s locust haul averaged seven tons a night. The project team weighed the locusts and sold them to nearby plants making chicken feed. Farmers netted up to 20,000 Pakistani rupees (USD 125) per person for one night’s work.
• “On the first day in the field we had to send the word out and around 10-15 people showed up,” says Ali. But word of the money to be made spread quickly, and hundreds of people showed up by the third day. “We did not even have to provide them with bags, they brought their own on their motorbikes. All we did was to weigh the bags and check that they were indeed full of locusts, and then pay them for their efforts.”

High Protein:

• Muhammad Athar, the general manager Hi-Tech Feeds (within the Hi-Tech Group, one of Pakistan’s biggest poultry breeders and animal feed makers), says his firm fed the bug-based feed to its broiler chickens in a five-week study. “All nutritional aspects came out positive – there was no issue with the feed made from these locusts. If we can capture the locusts without spraying on them, their biological value is high and they have good potential for use in fish, poultry, and even dairy feed,” he says.
• There are an estimated 1.5 billion chickens being raised in Pakistan plus innumerable fish farms – all of which could potentially buy high protein locust meal.
• “We currently import 300,000 tons of soya bean and after extracting the oil for sale, we use the soya bean crush to use in animal feed. Soya bean has 45% protein whereas locusts have 70% protein. Soya bean meal is 90 Pakistani rupees per kilogram (USD 0.5), whereas locusts are free – the only cost is capturing them and drying them so they can be sold as a useable product,” says Athar.

 Commercial interest:

• The processing cost of drying and milling locusts is only 30 Pakistani rupees per kg (USD 0.19). As Pakistan imports soya beans, he sees substantial potential savings in foreign exchange costs too.
• Right after the pilot study, the coronavirus pandemic forced Khurshid and Ali to put any further moves to scale up the project on hold, despite interest from large-scale commercial operators.
• Now that the lockdown has been eased in Pakistan, Ali says they can start again. All that is needed is for the local community to collect the locusts and sell them. “There are so many jobless people because of the pandemic. They can all be put to work collecting the locusts and selling them,” he says. Furthermore, rice-milling firms now have spare summer capacity, as rice is usually milled in winter.
• “It’s an out-of-box solution – it could easily be scaled up in our populated rural areas. Yes, in our desert areas where locusts breed chemical sprays make sense but not in areas where we have farms with crops and livestock and people,” says Ali.
• “It’s a very good idea – the only missing part is the buy-back mechanism,” says Khan, who heads Sindh’s Technical Department of Plant Protection. “Who will pay the local community for the locusts they collect? The animal feed industry needs to get involved.”
• Pakistan’s official locust action plan funded the National Disaster Management Authority to procure insecticide and aircraft. “This is a coordinated effort involving the NDMA, the Ministry of Food Security and provincial agricultural departments, and the provincial disaster management authorities. We have been spraying extensively in the desert areas in the locust breeding areas. You can’t eradicate locusts but you can control them,” he says.
• Khurshid said that as massive locust swarms are expected from the end of May, the local communities should be encouraged to catch locusts through buyback guarantees as soon as possible. The government, he pointed out, should both support and encourage private poultry and animal meal enterprises to buy the locusts and should stop spraying in areas where community-based locust collection is possible.
• Ahmed advocates a strategy of mass netting. “Nets, which can be as high as 50 feet stretched across poles in the ground, are a one-time cost and they can keep catching the locusts as they come in multiple swarms,” he says.
• Large scale development of indigenous natural pesticides like neem tree oil could also play a role as locusts will not touch plants sprayed with it, says Helga Ahmed, a veteran environmentalist based in Islamabad.

Locust’s impact on Agriculture:

Locust swarms devastate crops and cause major agricultural damage which results in famine and starvation. Though they occur in many parts of the world, locusts are most destructive in sustenance farming regions of Africa.

Desert locust plagues may threaten the economic livelihood of one-tenth of the world’s humans. Each locust can eat its weight in plants each day, so a swarm of such size would eat 423 million pounds of plants every day.

Locusts devour leaves, flowers, fruits, seeds, bark, and growing points, and also destroy plants by their sheer weight as they descend on them in massive numbers.

Locusts damage crops worth Rs 10 crore during the 1926-31 plague cycle. During the 1940-46 and 1949-55 locust plague cycles, the damage was estimated at Rs 2 crore each and at Rs 50 lakh during 1959-62 locust plague cycle.

Bhuj in Gujarat saw the last upsurge in 1993. This time locust swarms have destroyed standing crops of castor, cumin, jatropha, cotton, and potato, and fodder grass in around 20 talukas. Gujarat has not witnessed such an invasion of locusts since 1993-94. The invasion has damaged crops in half a dozen districts in the state.  

Measures to tackle the locust attack:

In the past, management strategies have typically focused on burning tires to create an exclusion zone, catching them in nets or digging trenches. However, these local measures will prevent locusts from reaching a particular area, but can do little to halt the progress of the swarm.

Currently, the most commonly used control is insecticide. Sprayed from land or aerial vehicles, whole swarms can be targeted in relatively short periods of time. However, this has led to some environmental concerns.

Allowing reptiles, the natural enemies of the locusts to thrive all year, prevents locust breeding. 

A more promising remedy is biological control mechanisms. Natural predators such as wasps, birds, and reptiles may prove effective at keeping small swarms at bay. 

However, for managing more established swarms, newly-developed targeted microbial biopesticides, such as the fungus-based “Green Muscle”, offer a larger-scale solution.

Scientists stress an integrated locust management system therefore must combine both chemical and biological methods to produce optimum results.

The most effective way to avoid the devastating effects of locust plagues is to prevent them from happening in the first place. In this regard, locust monitoring stations collect data on weather, ecological conditions, and locust numbers, making forecasts of the timing and location of breeding.

What are Locusts and grasshoppers’ economic considerations for management?

There are many economic and financial implications that need to be considered when choosing a management option. These may include:

Pre-crop

Understand the potential risk of a locust and grasshopper plague and potential yield losses associated with feeding damage.

• Locusts and grasshoppers are a chewing pest that can cause considerable damage, including complete defoliation if pest populations are high enough.
• Crops that are beginning to dry off when locusts begin to fly are susceptible to damage; locusts cause little if any damage to crops that have dried off.
• ‘Green bridge’ feed is required for the autumn generation of pests to lay sufficient eggs to pose a risk for crops in spring.
• High risk: locusts were on your farm for one to four weeks during April and May and you observed egg-laying.
• Moderate risk: locusts were on your farm for less than a week and there was egg-laying in isolated areas.
• Low risk: locusts pass through your property and you observe no egg-laying.

Assess the costs and benefits of taking preventative action:

• If there was locust activity in autumn, check for egg-bed hatching in spring and monitor hopper numbers.
• Insecticides are not effective repellents against attack. It is not possible to spray prior to a swarm or band arriving to prevent the locusts from entering a crop.

Assess the cost and benefits of controlling against the development of a ‘green bridge’ (self-sown cereals and grass weeds) in order to reduce exposure to attack: 

• These plants will support the egg-laying of locusts or hoppers. Destroying them, prior to sowing will also conserve soil moisture and lessen the probability of disease carry-over such as rust.

In-crop

Compare the costs, benefits, and risks of each management option against the alternative option of doing nothing.

• What are the likely outcomes of each management option? When the result of treatment is unknown consider the most likely (expected), as well as the worst and best results from each treatment option. Results from treatment will depend on the age of locust, crop stage, amount of green matter, wind conditions, and time of day of spraying.
• Are there any options to minimize damage? Cutting crops for hay or windrowing them in preparation for harvest can minimize locust damage or eliminate the need for chemical control. Baling or slagging crops and pastures before locust’s hatch is another management tool.
• If applying insecticide at the same time as other treatments only assess the additional cost of chemical application, i.e. the cost of going over the paddock is not included as it would have been incurred anyway. The additional cost is the specific cost of the insecticide and any additional time needed to prepare and apply.
• Consider costs and benefits for both ground and aerial application methods.
• Consider the time it will take to spray for control – will contractors be required? If so, include them in the costs.
• Check for and assess the cost of off-target impacts of spraying, including nearby livestock, bees, aquaculture, organic production, dams, and waterways. Ensure that all required buffer zones are observed to minimize environmental impacts.
• Observe insecticide withholding periods and consider implications associated with having to possibly harvest later than planned.
• Consider choosing a treatment option where the expected return is sufficient to offset the risk of the treatment. We all have different attitudes to risk when making decisions. The probability (risk) of outcomes can be affected in terms of responsiveness (efficacy), application rates, products, application methods, treatment costs, climatic conditions, and crop prices. The economic calculator can assist with this decision.

Consider risks, costs or savings associated with a no-treatment option or delaying treatment option:

• When calculating the cost of non-treatment, assess the potential risk of yield losses and grain quality downgrades. This will depend on the size of the hopper or locust population and how early the infestation starts or is detected in the crop. Crops most at risk are those containing green plant matter. Locusts cause little if any damage to crops that have dried off.

Consider the potential risk of re-infection and costs of further treatment:

• The length of time an insecticide is effective depends on the active ingredient, and rate of application. Climatic conditions and the remaining length of the growing season will affect the likelihood of follow up treatments.

Ignore all previous treatment costs in assessing current management options.

• Costs associated with previous treatments are ‘sunk costs’ and should be ignored as they will have no impact on the economic benefit of taking action now, i.e. even if the current treatment results in the crop not breaking even, provided the additional benefit of the treatment exceeds the cost of treatment, then the economic return from treatment will still be higher than doing nothing.
• Review received standards for locust or hopper contamination and assess risks and costs of possible downgrades. Receival standards vary with crop type. At the time of writing for cereal crops (wheat, durum wheat, barley, triticale, and oats) the maximum allowed live or dead is three field insects per half liter of grain or seed. One locust counts as one field insect.

Post-crop

• There are no post-crop economic considerations.

Nargis Naheed¹

Muhammad Dilawaiz Khan²

Zunaira Maqsood¹

Iqra Mehmood¹

Zainab Toheed¹

¹Department of Zoology, Wildlife and Fisheries, University of Agriculture, Faisalabad-38000, Pakistan

²Department of Agronomy, University of Agriculture, Faisalabad-38000, Pakistan