Preventive control consists in appropriate monitoring of locust habitats at key periods of their development in order to allow early detection of number increase and behaviour change, and results in adequate early warning and early reaction; it aims at reducing occurrence and intensity of locust outbreaks and preventing their development into major upsurges.
Why is it the best solution? What are the comparative advantages?
Alternatives to preventive approach are curative or palliative responses implemented in an emergency context, i.e. when crisis already arose, which is not satisfactory. Preventive approach offers the following comparative advantages:
· Reduced damage on crops and rangelands and therefore preservation of food security and livelihood of highly vulnerable rural communities;
Appropriately applied preventive approach allows reacting before significant increase of locust populations occur. Curative or palliative responses intervene only when there the outbreak is declared, which means already effective and much more important damage, with negative impact on food security.
· Reduced negative impact on human health and the environment
Preventive approach allows early detection of change in behaviour and increase in locust populations. This means that control operations can be carried out: a) at an early stage of locust development, both in terms of biology (hoppers instead of adults) and population dynamics (local infestations instead of major outbreak; locust populations not yet in gregarious phase); and b) when there is no immediate threat on cropping areas. This enables to spray slow-acting pesticides (such as IGR on hopper or bio-pesticides, sometimes applied in barriers) which are less hazardous for human health and the environment, or of small quantities of chemical products on well-defined targets usually located in relatively remote areas, i.e. far from crops and inhabited zones.
On the contrary, in presence of a major outbreak, the primary objective is the quick mortality of a high percentage of locusts in order to protect crops. This involves widespread full-cover spraying of huge quantities of chemical pesticides (fast-acting products) close to (or in) cropping areas and in the vicinity of inhabited zones. Inhabitants in the infested areas have to be aware of and adopt withholding periods for themselves, their cattle and their crops/harvests. Spraying, handling and storage of high quantities of pesticides also expose directly and for variable durations numerous workers whose health has to be monitored. Last, as chemical pesticides are not specific to locusts, non-target fauna can be affected (incl. beneficials such as bees), which also needs to be monitored.
· Reduced financial costs
Experience demonstrates that massive control operations are very expensive. Carried out during emergency contexts, i.e. during locust outbreaks and with inadequate preparation, they imply costly measures, which are the rapid procurement of huge quantities of pesticides and equipment, massive and immediate recruitment of additional human resources often not well-prepared or without updated knowledge, contracts for survey and control flying hours, etc. The cost of monitoring potential side-effects on human health and the environment of widespread use of high quantities of chemical pesticides has also to be added, as well as costs for mitigation, i.e. disposal of empty pesticide drums, obsolete pesticides and contaminated soils, improvement of pesticide warehouse and storage conditions for remaining pesticides, etc.
Preventive approach is a valuable solution to considerably reduce such costs. It implies long-term and streamlined locust management, that is to say an integrated strategy which take into account all situations and all aspects, including preparedness and contingency plans.
In other words, the preventive approach is the only long-term sustainable solution.
This strategy is the result of a long history of applied research carried out from the beginning of the 20th century, with solid scientific bases and extensive field practice.
Its value has been demonstrated by FAO’s experience in other geographical areas with other transboundary pests, in particular in the framework of the Programme EMPRES (Emergency Prevention System for Transboundary Animal and Plant Pests and Diseases) – Desert Locust Component.
Core principles of the preventive approach
- Monitoring and early detection
- Early warning
- Early reaction
- Information and forecasting
- Preparedness for locust campaign
- Contingency planning
- Up-to-date and environmentally sound survey/control methods and technologies
- Close cooperation between all stakeholders