Locust is the common name for any member of several species of short-horned grasshoppers of the family Acrididae.
They do not belong to a particular genus or subfamily, but are those species of grasshoppers that exhibit behavioral, morphological, and physiological changes from a solitary phase to a migratory phase.
Locusts are normally solitary and actively avoid contact with each other. But when conditions are right, particularly after lots of rain, contact becomes unavoidable. As the insects bump against one another, they begin to change. In an hour or so they become attracted to each other and swarm together.
During the course of one or two successive generations they actually change in shape and color, becoming bold yellow or green rather than the neutral brown of solitary locusts. These two phases look so different that until the 1920s, scientists believed they were actually two separate species.
They are from 1.25 to 7.5 centimeters (0.5 to 3 inches) in length.
Locusts are found on all continents except Antarctica and North America. They are most common in Africa and Asia.
Locusts diet – Large swarms of locusts can completely strip the foliage and stems of plants such as forbs and grasses. Some species consume a variety of plants, while others have a more specific diet. They often eat dry plant matter on the ground and will forage for weak or dead grasshoppers when plant food is scarce.
The desert locust is probably the best known species. It inhabits dry grasslands and deserts from Africa to the Punjab (state in northern India) and can fly upward to about 1,500 meters (5,000 feet) in huge towers of individuals. They gather in swarms larger than any other single congregation of organisms on Earth, ranging from 100,000 to 10 billion insects. One swarm in 1794 once spread over 5,000 square kilometers (almost 2,000 square miles).
The Rocky Mountain locust a species that is now extinct, destroyed millions of dollars worth of crops on the Great Plains between 1874 and 1877; they became extinct in 1902.
In 1954, a swarm of locusts flew from Africa all the way to Great Britain, decimating crops along the way. Another swarm in 1988 made it from Africa to the Caribbean.
These massive swarms travel as many as 160 kilometers (100 miles) a day.
When locusts rub against each other, the contact increases serotonin levels. The normally shy and solitary insects become social and crave more contact with others. Scientists discovered artificially increasing locusts’ serotonin levels in a lab environment caused the transformations in appearance and behavior seen in swarm development. In contrast, blocking serotonin kept the insects calm despite contact with others.
Unlike other insects such as butterflies and houseflies, locusts do not undergo a complete metamorphosis. Locusts go through egg, nymph and adult stages — lacking the pupa stage. Fledgling is an intermediate stage that occurs between the nymph and adult periods. Their life cycle period varies depending on the species of the locust.
Study of literature shows how pervasive plagues of locusts were over the course of history. The insects arrived unexpectedly, often after a change of wind direction or weather, and the consequences were devastating.
The Ancient Egyptians carved locusts on tombs in the period 2470 to 2220 BC.
A devastating plague is mentioned in the Book of Exodus in the Bible, as taking place in Egypt around 1446 BC.
In the Book of Revelation, locusts with scorpion tails and human faces are to torment unbelievers for five months when the fifth trumpet sounds.
The Iliad mentions locusts taking to the wing to escape fire.
Plagues of locusts are also mentioned in the Quran.
In the 9th century BC, the Chinese authorities appointed anti-locust officers.
They are also edible insects; they have been eaten throughout history and are considered a delicacy in many countries.
The Bible records that John the Baptist ate locusts and wild honey while living in the wilderness.
The Torah, although disallowing the use of most insects as food, permits the consumption of certain locusts; specifically, the red, the yellow, the spotted grey, and the white are considered permissible.
In the world and especially in Asia locusts are cooked in many ways including fried, smoked, or dried.