Alexander John Nicholson (25 March 1895 - 28 October 1969) was an Irish Australian

Irish Australian

Irish Australians have played a long and enduring part in Australia's history. Many came to Australia in the eighteenth century as settlers or as convicts, and contributed to Australia's development in many different areas....

 entomologist who specialised in insect population dynamics

Population dynamics

Population dynamics is the branch of life sciences that studies short-term and long-term changes in the size and age composition of populations, and the biological and environmental processes influencing those changes...

. He was Chief of the CSIR / CSIRO

Commonwealth Scientific and Industrial Research Organisation

The Commonwealth Scientific and Industrial Research Organisation is the national government body for scientific research in Australia...

 Division of Economic Entomology for 24 years and is credited with initiating the professional era in Australian entomology. He was a Foundation Fellow of the Australian Academy of Science

Australian Academy of Science

The Australian Academy of Science was founded in 1954 by a group of distinguished Australians, including Australian Fellows of the Royal Society of London. The first president was Sir Mark Oliphant. The Academy is modelled after the Royal Society and operates under a Royal Charter; as such it is...

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He is notable for the Nicholson-Bailey model

Nicholson-Bailey model

The Nicholson–Bailey model was developed in the 1930s to describe the population dynamics of a coupled host-parasite system. It is named after Alexander John Nicholson and Victor Albert Bailey....

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