The Migratory locust is
widely distributed throughout the Old World, in Africa, south of the Sahara, in
the Arabian and Indo-Pakistani peninsulas, Europe and Mediterranean borders,
eastern Asia and Australia. However, it is not found in both Americas. There
are at least a dozen migratoria
sub-species and each is bio-ecologically adapted to the specific ecoclimatic
characteristics of their environments. The Migratory locust seeks heat (optimal
temperatures of 20°-25°C), average humidity environments (optimal rainfall of
50-100 mm/month) and colonizes steppes and savannahs with little or no tree
cover. It is quite a strict graminivore that is able of causing considerable
damage to grain crops and even plantations during outbreak periods. In
temperate regions, the Migratory locust undergo embryonic diapause in response
to the harsh winters. In such conditions there are 1 or 2 generations per year.
This obligatory developmental arrest does not occur in subtropical and tropical
subspecies such as Locusta migratoria
migratorioides which is able to breed continuously by migrating hundreds
of kilometres to encounter ecological conditions that will enable them to
survive. This locust can produce 3 to 5 generations per year by utilizing
seasonally complementary ecological areas. Hence, their life cycle is rapid
when the weather is hot and wet.
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| Distribution map of Migratoty locust |
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