Desert locust invasions and what are they looking for? – A review
Simranpreet Singh Bola
Insects have reined the world earlier than mankind and are present everywhere right from below the earth to hill top. Insects are very much associated with man’s life. While some are beneficial, others are highly harmful to mankind, one of which is Desert locust, the most harmful insect in the world. They are scourge of mankind since time immemorial. Desert locusts have highly migratory habit, marked polymorphism and voracious behavior of feeding. They are proficient of forming swarms (adult’s congregation) and hopper bands (nymphal congregation), causing great devastation to natural and cultivated vegetation. They are the sleeping giants that can outburst any time to inflict heavy damage to the crops leading to national emergency of food and fodder. The invasion area of desert locust covers about 30 million square kilometers which includes whole or parts of nearly 64 countries. This includes countries like North West and East African countries, Arabian Peninsula, the Southern Republic of USSR, Iran, Afghanistan and the Indian sub-continent etc. When locust occurs in low densities, during recession periods, it inhabits a broad belt of arid and semi-arid land which stretches from the Atlantic Ocean to North West India. Thus, it covers over 16 million square kilometers in around 30 countries. The migratory behavior of the Desert Locust is an adaptation to survive in arid environments. In reality, it is neither hunger nor fleeing their cannibalistic peers that push these insects to migrate. This migratory behavior is the result of a long evolution which allowed this species to adapt perfectly to its desert environment. In these areas, favourable rains for breeding and food plant production occur episodically, and are randomly scattered over large areas. Under these unpredictable conditions, migrating thus, is necessary for Desert Locust survival.