The question of whether locusts are extinct can be answered directly: no, they are not. These insects continue to exist and periodically impact ecosystems and human societies across many regions of the world. While misconceptions about their status persist, locusts remain a significant biological phenomenon. They are very much alive and continue to be a part of various global environments.
Understanding Locusts
Locusts are a specific type of short-horned grasshopper (family Acrididae) known for their dramatic transformation into a “swarming phase” under certain conditions. This shift, called phase polyphenism, is triggered by increased population density, leading to physiological and behavioral changes. Serotonin is a key chemical in their brains that makes them gregarious and nomadic.
Their life cycle has three stages: egg, nymph (hopper), and adult. Females lay eggs in moist soil, often in pods. Wingless nymphs emerge, go through several growth stages (instars), and shed their exoskeleton before developing wings and reaching adulthood.
Solitary locusts behave like typical grasshoppers, seeking isolation. However, gregarious locusts are attracted to other locusts and form dense, highly mobile bands of nymphs and flying swarms of adults.
Addressing the Misconception
The idea that locusts are extinct is a misconception, likely stemming from several factors. One reason for this belief is the episodic nature of locust outbreaks; they are not always visible in large swarms, leading to periods of lower public awareness.
The Rocky Mountain locust (Melanoplus spretus), a North American species, went extinct in the early 20th century, with the last sighting in 1902. This was an isolated event, not representative of all global locust species.
Historical accounts of massive locust plagues, often depicted in ancient texts, contribute to the perception that these destructive swarms are relics of the past. Additionally, confusion can arise from other insects, such as periodical cicadas, which are sometimes mistakenly referred to as “locusts” due to their large, synchronized emergences, even though they are distinct insect types. Despite these historical and perceptual factors, the insects themselves have never disappeared from most parts of the world.
Locusts in the Modern World
Locusts remain active globally, especially in Africa, the Arabian Peninsula, and Asia. The Desert Locust (Schistocerca gregaria) is a destructive migratory pest due to its mobility and ability to form massive swarms. Swarms travel up to 150 kilometers daily, consuming vast green vegetation, including crops and pastures.
A small swarm (one square kilometer) can hold 80 million locusts, consuming food equal to 35,000 people daily. Locusts also play an ecosystem role in arid regions as a food source and through nutrient cycling (frass).
However, swarms negatively impact human populations, causing significant crop losses and threatening food security. Recent outbreaks (2019-2022 in East Africa, Arabian Peninsula, Indian subcontinent) highlight their ongoing challenge to agriculture. Despite modern control, large swarms form when conditions like drought followed by rainfall favor rapid breeding.
Understanding Locusts
Locusts are a specific type of short-horned grasshopper belonging to the family Acrididae, distinguished by their ability to undergo a dramatic transformation in behavior and morphology under certain environmental conditions. They are not a separate taxonomic classification from grasshoppers, but rather certain grasshopper species that exhibit a “swarming phase”. This shift, known as phase polyphenism, is triggered by factors like increased population density, which leads to changes in their physiology and behavior. Serotonin in their brains is a key chemical that triggers these changes, making them gregarious and nomadic.
The life cycle of a locust typically involves three stages: egg, nymph (also called hopper), and adult. Female locusts lay eggs in moist soil, often in clusters called pods. After hatching, wingless nymphs emerge and go through several growth stages, or instars, shedding their exoskeleton multiple times before developing fully formed wings and reaching adulthood. While solitary locusts behave much like typical grasshoppers, seeking isolation, gregarious locusts are attracted to other locusts and form dense, highly mobile bands of nymphs and flying swarms of adults.
Addressing the Misconception
The idea that locusts are extinct is a misconception, likely stemming from several factors. One reason for this belief is the episodic nature of locust outbreaks; they are not always visible in large swarms, leading to periods of lower public awareness. While a specific North American species, the Rocky Mountain locust (Melanoplus spretus), did go extinct in the early 20th century, this was an isolated event and not representative of all locust species globally. The last recorded sighting of a live Rocky Mountain locust was in 1902.
Historical accounts of massive locust plagues, often depicted in ancient texts and folklore, might also contribute to the perception that these events are relics of the distant past. Such historical narratives can make it seem as though these destructive swarms no longer occur. Additionally, confusion can arise from other insects, such as periodical cicadas, which are sometimes mistakenly referred to as “locusts” due to their large, synchronized emergences, even though they are distinct insect types. Despite these historical and perceptual factors, the insects themselves have never disappeared from most parts of the world.
Locusts in the Modern World
Locusts remain an active and relevant presence across various parts of the globe, particularly in Africa, the Arabian Peninsula, and Asia. Species like the Desert Locust (Schistocerca gregaria) are considered among the most destructive migratory pests due to their mobility and ability to form massive swarms. These swarms can travel significant distances, sometimes up to 150 kilometers in a single day, consuming vast amounts of green vegetation, including crops and pastures. A relatively small swarm, covering just one square kilometer, can contain up to 80 million locusts and consume as much food in a day as 35,000 people.
These insects also play a role in ecosystems, especially in arid and semi-arid regions where they are a food source for various animals and contribute to nutrient cycling through their waste, known as frass. However, their impact when swarms occur is overwhelmingly negative for human populations, leading to significant crop losses and threatening food security for millions. Recent outbreaks, such as those from 2019 to 2022 in East Africa, the Arabian Peninsula, and the Indian subcontinent, underscore their ongoing relevance and the challenges they pose to agriculture and livelihoods. Despite modern surveillance and control efforts, large swarms can still form when environmental conditions, such as periods of drought followed by abundant rainfall, favor rapid breeding and population growth.