April 2006
The Desert Locust
Order Family Genus and Species
Orthoptera Acrididae Schistocerca gregaria
The "Desert Locust" or grasshopper appears in arid
parts of Africa and Asia and is greatly
feared because of its ability to reproduce rapidly and because of its
skill at adapting to the
harse environment found in the various deserts which cover Africa and
parts of Asia. Farmers
especially dread this locust species since large
swarms can strip vegetation from trees, plants,
and crops for many miles.
There are accounts of huge swarms of locusts mentioned in the bible.
Swarms so large that they
literally turned day into night and devoured all vegetation in their
path. Locusts are also linked
to various plagues which have tormented mankind for untold ages.
Luckily, locust swarms of that
size and intensity are few and far between
and even when they do occur, natural enemies and
modern insecticides keep them under control. The graphic below
shows a large swarm of locusts
as they sweep across the savanna grasslands of Africa. The last
locust plague occurred from 1986
to 1989. Locusts are often used
as a food source by civilizations affected by the devastation of
their crops and other vegetation and, even today, locusts
can be purchased as food items....often
covered with chocolate and various other concoctions.
Locusts are one of over a dozen species classified as
short-horned grasshoppers which use their
large hind legs to leap large distances, they are different from our
domestic grasshoppers in the
fact that they can alter their behavior and activities
to endure the savage conditions of the desert.
When food is plentiful these locusts may maintain a solitary existence,
looking out for their own
welfare but in times of stress....when food is scarce and arid conditions
are even more demanding,
they often band together to search not only for food for themselves
but for others of their kind.
Locusts which are solitary hunters are of a brownish
shade with dark spotting; immature adults
take on a pinkish color shown in the insect
pictured at the top of the page. This is a phenomenon
which, for years, had scientists and entomologists thinking that there
were two separate species
present. It is thought this color-morphing occurs due to aging.
Mature locusts are of a yellowish
color. These insects are one of the most destructive creatures
in the world with large swarms
(40-50 million insects) eating enough
vegetation and crops to feed more than 500
people for a
year.
Adult locusts are around 2 1/2 to 3 inches long,
weigh 1/3 to 1/2 ounce and are capable of
sustained flight.....sometimes traveling vast distances. They
can fly for 15-16 hours at a time
at a speed of 9-12 m.p.h., usually downwind
and have been documented to have covered
over 2000 miles in a one month period.
Females lay from 75 to 100 eggs at a time
in soft soil
to a depth of around 1/2 inch with an incubation period of between
14 to 65 days, depending
on the temperature and the moisture available in the soil. After hatching,
hoppers go through 5
stages (instars) of development, shedding
their outer skin each time until finally they emerge as
a smaller replica of an adult, complete with wings.... which will rapidly
develop in strength.
The lifespan of the desert locust is around 5-6 months, but is affected greatly by environmental
conditions.
Press play below, to hear Locust sounds.