CONTEXT<\/strong><\/span><\/p>\n Desert locusts normally live and breed in semi-arid\/desert regions.<\/strong> For laying eggs, they require bare ground, which is rarely found in areas with dense vegetation. So, they are more likely to breed in Rajasthan than in the Indo-Gangetic plains or Godavari and Cauvery delta.<\/strong><\/span><\/p>\n While green vegetation is good for hopper development \u2013 the stage between the nymph that has hatched and before its turning into a winged adult moth \u2013 such cover isn\u2019t widespread enough in deserts to allow growth of large locust populations.<\/p>\n ANALYSIS<\/strong><\/span><\/p>\n Locusts aren\u2019t dangerous as long as they are individual hoppers\/moths or small isolated groups of insects, in what is called the \u201csolitary phase\u201d.<\/strong><\/span> It is when their population grows to large numbers \u2013 the resultant crowding induces behavioral changes and transformation from the \u201csolitary\u201d to \u201cgregarious\u201d phase \u2013 that they start forming swarms.<\/p>\n A single swarm contains up to 40-80 million adults in one square km and these can travel up to 150 km in one day.<\/strong><\/p>\n The above large-scale breeding and swarm formation, however, takes place only when\u00a0conditions turn very favourable in their natural\u00a0habitat, i.e. desert and semi-arid regions. These areas should get rains that will produce enough green vegetation to enable both egg\u00a0laying and hopper development.<\/p>\n The main locust breeding areas in the\u00a0Horn of Africa, Yemen, Oman, Southern Iran and Pakistan\u2019s Baluchistan and Khyber Pakhtunkhwa provinces recorded widespread rains in March-April. East Africa, in fact, had its wettest rainfall season in over four decades even during October-November.<\/strong><\/span><\/p>\n The hopper bands and immature adult groups resulting from this large-scale breeding \u2013 itself a product of unusually heavy rains \u2013 are the ones\u00a0that started arriving in Rajasthan<\/strong>\u00a0during the first fortnight of April.<\/p>\n The Union Agriculture Ministry\u2019s Locust Warning Organisation<\/strong> then observed \u201clow-density I & II instar gregarious\/transient hoppers\u201d at Jaisalmer and Suratgarh in Rajasthan and Fazilka in Punjab adjoining the Indo-Pakistan border.<\/p>\n Subsequently, there has been arrival of swarms from the main spring-breeding areas. And these swarms have come not only to western Rajasthan, but also moved to the eastern parts of the state and even Madhya Pradesh and Maharashtra. Much of this movement, it seems, was aided by the strong westerly winds from\u00a0Cyclone Amphan in the Bay of Bengal<\/strong>.<\/p>\n Thus, there are two meteorological drivers behind the current locust invasions: \u00a0one, unseasonal heavy rains in the main spring-breeding tracts in March-April, and, two, strong westerly winds.<\/strong><\/span><\/p>\n The United Nations\u2019 Food and Agricultural Organisation<\/strong> has further said that \u201cseveral successive waves of invasions can be expected until July in Rajasthan with eastward surges across northern India as far as Bihar and Orissa\u201d. But after July, there would be westward movements of the swarms, as they will return to Rajasthan on the back of the changing winds associated with the southwest monsoon.<\/p>\n <\/p>\n An important thing to note<\/strong> is the current swarms are all of \u201cimmature locusts\u201d. These are locusts that voraciously feed on vegetation, but have not yet laid eggs.<\/p>\n Once they start breeding, the swarm movement will cease or slow. Also, the breeding will happen mainly in Rajasthan.<\/p>\n So far, the swarms haven\u2019t caused much damage, since the rabi crop has already been harvested and farmers are yet to start kharif sowings.<\/p>\n One reason for the swarms migrating eastwards<\/strong> \u2013 normally they are seen in India only after July post the monsoon\u2019s arrival, while confining themselves mostly to the desert areas of West Rajasthan where they breed and exist as solitary insects or in isolated groups \u2013 has been their search for food.<\/p>\n These insects need to munch enough \u2013 roughly their own weight in fresh food every day \u2013 before being ready for mating.<\/p>\n The danger would be when the swarms that have already or are about to come will start breeding.<\/p>\n A single gregarious female locust can lay 60-80 eggs three times during its average life cycle of 90 days.<\/p>\n If their growth is coterminous with that of the kharif crop, we could well have a situation similar to what maize, sorghum and wheat farmers of Kenya, Ethiopia and Somalia experienced in March-April.<\/p>\n A proactive exercise of control, through aerial spraying of ultra-low volume of concentrated insecticides in all potential breeding sites, is required,<\/strong><\/span> along with continuous monitoring of the crops during the ensuing kharif season.<\/p>\n <\/p>\n For more such notes, Articles, News & Views Join our Telegram Channel.<\/strong><\/span><\/p>\n![\"India](\"https:\/\/www.freshfruitportal.com\/assets\/uploads\/2020\/05\/1280px-Locusta-migratoria-wanderheuschrecke-1024x716.jpg\")
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