Are fluctuations in locust numbers in Australia associated with El Ni?o or La Ni?a events?
In Australia, strong El Ni?o* and La Ni?a* events have some influence on locust numbers but cannot entirely explain the incidence of plagues. Locust plagues sometimes do, but not always, occur when there is a strong La Ni?a event as this is associated with above average rainfall. However, above average rainfall may not necessarily lead to a locust outbreak, as the critical factor in the development of a plague is the timing of rainfall events in relation to breeding (see FAQ 4).
