Courses
Courses for Kids
Free study material
Offline Centres
More
Store Icon
Store

Locust Life Cycle

share icon
share icon
banner

All Locust are grasshoppers, but not all grasshoppers are Locust. Locust is a handful of grasshoppers when they enter a swarming phase. A series of factors that vary by geographical area weather and species force grasshoppers to crowd each other. Their serotonin rises at that point and they begin to swarm, this kind of behavior is referred to as Gregariousness. This is called a rapid onset of social behavior. The mode of identifying the Locust from the grasshopper all comes down to how they behave. There are thousands of species of Locust in which at least 500 are known to cause crop damage and 50 are considered as major pests. Their reputation for destruction is very epic, you will not believe it until you see it happening. Locust swarms are of 3 types depending upon their population density they are as follows: outbreak, upsurge, and plague. Small pockets of swarms that are happening in a localized area are called an Outbreak. The large groups of such are called Upsurge, these are geographically confined. When large giant groups of Locust separated by different breeding locations all swarms together are called Plague. Gregariousness is usually caused when a Locust touches each other by their hind leg. As the population density increases typically due to shortage of food or a drought, typically this kind of contact physical contact increases as Locust comes together. This constant hind leg touching and tickling release a large number of neurotransmitters called Serotonin. This Serotonin is one of the happy hormones in humans which is typically released when we exercise and it regulates our moods. When the Locust is touching each other there is huge Serotonin buildup in their bodies in Locust whose hind legs are stimulated. Experiments have shown that this can occur in as few as 10 Locust if they are tightly packed. When these swarms they tend to adopt the aligned movement thereby flying or marching collectively. The flightless young once of the Locust are called Nymph, these are the once that march and they sprout wings they fly. Gregariousness also induces physiological changes, wherein the Locust change color as well becoming the typical yellow-brown color which we associate with Locust changing from the green grasshopper color. All of these changes are caused or induced by Serotonin. Large swarms of Locust can contain crores or billions of individuals. Locust can fly 200 km a day destroying all food crops and all kinds of greenery in their path. An adult Locust is capable of eating 2 kg of food a day, you can say it can eat its own body weight. Locust always breeds exponentially, where once a female can lay from 30 to 100 eggs. The flight or migration of the Locust is aided by the wind and they tend to move with the wind flow. Locust has been known throughout history, as they have even been recorded in biblical times. The oldest record dates back to Egypt to 2500 BCE depicted on Egyptian tombs. 

The life cycle of a Locust has a few stages which are as follows.


Image will be uploaded soon

 

MATING

During this stage, the male locust finds a female locust of its species and inserts its semen into a sperm sac of the female which is found in the abdomen. In this process,  the sperm is deposited in the female oviduct and this is stored in the sperm sac waiting for the eggs. The female of the locust species then releases the eggs which mix with the male Locust semen and get fertilized as they pass through the oviduct. A male and a female Locust are distinguished by the shape of the tip of the abdomen. In comparison, the female Locust is bigger to the male Locust on average.

EGGS

Once the mating of the male and the female Locust is done, the female Locust finds a ground that is suitable for it to lay the eggs. The female makes a hole in the soil using their abdominal tip for it to lay the eggs by extending the membranes between the segments. The females then lay their eggs in the ground, this will be mostly in the warm damp soil or even in the sand. The female Locust lays the eggs in the groups of 50 which are deposited in the ground. These depositions where the eggs are laid in a shallow hole known as Pods, the deposition takes place 4 inches underground. The female Locust lays eggs somewhere around 50 to 100 eggs in a Pod at a time. Ther eggs are then later covered by foamy fluid, which hardens itself in order to protect the eggs acting as a protective barrier. The hatching of the eggs mainly depends upon the temperature and the moisture of the soil or sand. We can say it will take roughly 10 to 20 days for the eggs to hatch and the young once to come out. 

NYMPHS

Once the eggs are hatched the baby Locust comes out of the ground, by forcing their way to the surface. During this stage, they will not be having wings in them. They get around by hopping, that is how they get their name as hoppers. The duration in which they will be hopping is around 4 to 8 weeks, at this stage, they tend to gather in crowds. The baby Locust that comes out of the eggs is called Nymph or Hoppers. Post hatching them for over a period of 2 months the Nymph goes through 5 stages of molting called Instars. During each stage of the instars, the Nymph will shed their skin to allow for further development, this is done by pumping their body thereby trying to push their skin behind them. This is very hard work for them, but they seem to manage to perform it. This is done by attaching themselves firmly on a plant and very gently pushes itself further and further out of the old skin. When the Locust is completely out of the old body it hangs itself upside down for a while to rest. Later the soft body of the Locust begins to harden and the wings benign to open up. We can see the old skin of the Locust still hanging on the tree. Once they are out of their skin they start hopping. Post a few days they grow a little and their body becomes to harden and they become much darker in shade. As they continue to grow they shed their skin which is known as molting. Each time this happens they change color. At their initial stage, they will be having wing buds, which later grow fully as they reach adulthood. Over the completion of the 5th instar, we will see that the Locust wings will be fully developed at that time. 

FLEDGLINGS

As the wings of the Locust are soft and not fully developed, Nymph’s wings are very tiny and they will not be able to fly. At this stage they usually walk, their long back legs help them make enormous keeps. If frightened they can jump up to 100 times the length of their body. These flightless Nymphs are called the Fledglings, this happens after the 5th molt. They spend most of their day eating, usually lying along the leaf hoping no one would spot them. They have an armor plating on them which gives them some protection. The wing wings will take about a week to harden, post these fledglings will be able to fly around with them reaching adulthood. During this stage of development, they have to consume a lot of vegetation in order to store the energy which will be later useful to them for reproduction and flight. They usually stay with large groups and spend most of their time eating. Having long legs helps them to climb upon the grasses. They can eat a whole crop until there is nothing very less time. 


ADULTS

This is the final stage in the Locust life cycle, which involves a lot of movement and feeding. Locust at this stage will be having fully-fledged wings that are now fully developed and they will be capable of flying anywhere. It takes 2 weeks for fledglings to fully develop into an adult, we can say that now at this stage it is sexually mature. They tend to swarm together with the number somewhere around thousands, in the areas, especially where there are green feeds and they are very destructive in the garden areas. They usually travel in large swarms as they move from one feed to another after the exhaustion of the current feed. An adult Locust is said to have a lifespan of 8 to 10 weeks, during this period the male Locust mates with the female of the species to reproduce and die. They have their ears under the wings which look like holes there. Locust has tiny holes in the abdomen called the Spiracles, they breathe through them. The antenna on the head of the Locust is called Respules. The wings and the body have a lot more color during this phase still, there will be some changes that take place before the Locust is yellow in color.

Want to read offline? download full PDF here
Download full PDF
Is this page helpful?
like-imagedislike-image

FAQs on Locust Life Cycle

1. What are the main stages in the life cycle of a locust?

The locust life cycle is an example of incomplete metamorphosis and consists of three distinct stages:

  • Egg: Female locusts lay their eggs in pods, typically 10-15 cm deep in moist, sandy soil. Each pod can contain 20-100 eggs.
  • Nymph (or Hopper): After hatching, the wingless nymph emerges. This stage involves several (usually five) sub-stages called instars. The nymph grows larger with each instar, shedding its exoskeleton through a process called moulting.
  • Adult: After the final moult, the locust emerges as a winged adult, capable of flight and reproduction, thus completing the cycle.

2. How long does a locust typically live?

The total lifespan of a locust can range from a few months to almost a year, heavily depending on environmental conditions like temperature and food availability. The cycle duration is generally broken down as follows:

  • Egg stage: 10 to 65 days.
  • Nymph stage: 25 to 60 days.
  • Adult stage: 2 to 5 months, during which they mature and reproduce.
Favourable conditions can significantly shorten each stage, leading to rapid population growth.

3. What are the key differences between a locust and a grasshopper?

While all locusts are technically a type of grasshopper, not all grasshoppers can become locusts. The primary difference lies in their behaviour, a phenomenon known as phase polyphenism.

  • Behaviour: Grasshoppers are typically solitary creatures. Locusts, however, can switch from a solitary phase to a highly mobile, social gregarious phase when their population density becomes high.
  • Appearance: This behavioural change is accompanied by physical changes. Gregarious locusts are often darker in colour, have longer wings, and different body proportions compared to their solitary counterparts.
  • Impact: The key difference is the swarming behaviour. Locusts form massive, destructive swarms that migrate over long distances, while grasshoppers cause more localised damage.

4. How does a solitary grasshopper-like insect transform into a swarming locust?

The transformation is a remarkable example of phenotypic plasticity, triggered primarily by population density. When favourable conditions lead to a high number of locusts in a small area, the increased physical contact (especially touching of the hind legs) stimulates a surge of the neurochemical serotonin. This chemical cascade initiates a rapid change in behaviour and appearance, shifting the locust from its harmless solitary phase to the aggressive, swarming gregarious phase within just a few hours.

5. Where and how do locusts lay their eggs for optimal survival?

Female locusts choose their egg-laying sites carefully to maximise the chances of survival for their offspring. They use their ovipositor to drill into the ground and deposit a banana-shaped egg pod about 10-15 centimetres beneath the surface of moist, sandy soil. This depth protects the eggs from predators and prevents them from drying out. The female seals the pod with a frothy substance that hardens into a plug, further safeguarding the eggs until they are ready to hatch.

6. What are the common methods used to control locust populations and prevent swarms?

Locust control focuses on preventing swarms from forming or destroying them once they appear. Key methods include:

  • Chemical Control: This is the most common method, involving the spraying of insecticides on hopper bands or adult swarms, often using aircraft or vehicle-mounted sprayers. Poisonous bait is also used.
  • Biological Control: This involves using natural enemies of locusts, such as certain fungi (like Metarhizium acridum) or protozoan pathogens that specifically target and kill them without harming other organisms.
  • Monitoring and Early Warning: Governments and international organisations use satellite imagery and ground surveys to monitor vegetation conditions and detect early signs of locust breeding to enable preemptive control measures.

7. Why are locust swarms considered a more significant agricultural threat than a large population of grasshoppers?

The enhanced threat from locusts comes from their coordinated, migratory swarming behaviour. While a large number of solitary grasshoppers can cause significant local damage, they do not coordinate their movements. In contrast, a locust swarm acts like a single, massive organism. It can contain billions of individuals, cover hundreds of square kilometres, and travel up to 150 km a day. This mobility and sheer density allow a single swarm to decimate crops across vast regions in a very short period, leading to widespread famine and economic devastation far beyond the capacity of non-swarming grasshoppers.

8. What specific environmental conditions can trigger a locust outbreak?

Locust outbreaks are not random; they are triggered by a specific sequence of environmental conditions. The primary factor is unusually heavy and widespread rainfall in their normally arid habitats. This leads to:

  • Lush Vegetation Growth: Abundant green vegetation provides a plentiful food source, allowing locusts to thrive and reproduce rapidly.
  • Moist Soil: The damp, sandy soil creates ideal conditions for females to lay their egg pods, ensuring high hatching success.
These factors lead to a population explosion, forcing locusts into close contact and triggering the switch to the dangerous gregarious phase, which results in an outbreak.

9. How does the locust life cycle demonstrate incomplete metamorphosis?

The locust life cycle is a classic example of incomplete metamorphosis, also known as hemimetabolism. This type of development is characterized by three stages: egg, nymph, and adult. The key feature is that the juvenile stage, or nymph, largely resembles a smaller, wingless version of the adult. The nymph grows through successive moults (ecdysis), gradually developing wings and reproductive organs, without undergoing a pupal stage. This is different from complete metamorphosis (seen in butterflies), which includes a fourth, transformative pupal stage between the larva and adult.


Competitive Exams after 12th Science
tp-imag
bottom-arrow
tp-imag
bottom-arrow
tp-imag
bottom-arrow
tp-imag
bottom-arrow
tp-imag
bottom-arrow
tp-imag
bottom-arrow