Swarm , upsurge and plague
- July 20, 2020
- Posted by: OptimizeIAS Team
- Category: DPN Topics
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Subject: Environment
Context:
Food and Agriculture Organization (FAO) has warned India to remain on high alert against locust attack for the next four weeks.
Concept:
- The FAO has three categories of Desert Locust situations:
- Outbreak: It is common occurence
- Upsurge: current locust attack (2019-2020) has been categorised as an upsurge.
- Plague
- Upsurges and plagues do not occur overnight; instead, they take many months to develop.
- The last major plague was in 1987-89 and the last major upsurge was in 2003-05.
Locust attacks and developments:
- Before the outbreak stage, the FAO first issues ‘Desert Locust threats’ that are determined from an analysis of national survey and control data combined with remote sensing imagery and historical records. Such threats have been issued in 2012, 2013, and 2015. Not all threats develop into an outbreak.
- When there are good rains and green vegetation develops, desert Locusts which are always present somewhere in the deserts between Mauritania and India can rapidly increase in number and within a month or two, start to concentrate.