What is La Niña?
The Bureau of Meteorology has declared the first La Niña event from 2010 to 2012 and this can last between 1 to 3 years. La Niña is a natural cycle that is part of El Nino-Southern Oscillation (ENSO). It is caused by increased winds east to west that change ocean currents to draw cool waters from deep within the ocean. This helps increase the surface water temperature in the western Pacific and to the north of Australia. This results in more air, cloud development, and rainfall.
Differences between El Niño and La Niña
There are two key weather events at play here, El Niño and La Niña:
- El Niño – refers to the above-average sea-surface temperatures that periodically develop across the east-central equatorial Pacific. It represents the warm phase of the ENSO cycle.
- La Niña – refers to the periodic cooling of sea-surface temperatures across the east-central equatorial Pacific.
What are the effects of La Niña?
Increased rainfall in Australia is expected as a result. The six wettest years since 1900 were experienced during La Niña, with severe floods in 1955, 1988, 1998, and 2010. Eastern Australia experienced up to 20% more rainfall than the long term average.
Effects experienced as a result of La Niña include:
- Increased rainfall across most of Australia
- Cooler daytime temperatures
- Warmer overnight temperatures
- The shift in temperature extremes
- Increased cyclone numbers
The image above compares La Niña 2010 to 2012 to the average long-term rainfall.
This La Niña weather event could lead to a pest increase as conditions are optimal for breeding for some species.
Reducing the risk from Vector-Borne Diseases, especially from Mosquitoes
Reports suggest that climatic changes like La Niña have influences on vector-borne viruses and diseases, especially from mosquitoes. Mosquitoes require access to stagnant water in order to breed and humid conditions for viability, especially flooding and water pooling on surfaces.
Mosquito prevention at home
Some key callouts include:
- Remove debris from guttering and ensure correct drainage is present around roofing areas.
- Pots and any containers that could hold water should be removed from outside areas or turned upside down if possible.
The smallest amount of water can begin the mosquito breeding cycle.
Integrated Mosquito Management
Integrated Mosquito Management (IMM) treatments include detailed surface treatments along with mosquito recommendations to reduce conducive conditions. These services target both adults and larval stages. Ongoing visits will help manage mosquito presence throughout the year with the flexibility to intensify visits in the warmer months.
Australia is now moving towards a COVID normal with more emphasis on outdoor dining and home gathering for families. For one-off event treatments, there are mosquito services available for the lead up to these gatherings, addressing adult mosquitoes and reducing the risk of guests being bitten.
Movement of rodent populations
When potential flooding occurs, there is an increased movement of rodent populations to otherwise never experienced areas. Rodents will be in search of dry shelter, nesting areas, food sources, and breeding sites.
Take time to evaluate what your rodent solutions are for your home. Check for gaps and access areas, and keep an eye out for any rodent activity. If you have identified a rodent infestation issue, contact the Experts and book in a 123 Knockdown program.
La Nina, and pest management
Don’t be plagued by the presence of unwanted pests post rainfall and flooding.