Mabel Josephine Mackerras (1896-1971), entomologist and parasitologist, was born on 7 August 1896 at Deception Bay, Queensland, daughter of Cecilia Mary Bancroft (born Jones) and Dr Thomas Lane Bancroft, medical naturalist. She was educated at Brisbane Girls' Grammar, University of Queensland (BSc 1918, MSc 1930) and University of Sydney (MB 1924). With a Walter and Eliza Hall Fellowship in economic biology (1918-19) she began research in Queensland on tick resistance in cattle, fly- borne diseases of cattle and horses and fatal epizootics in fresh-water fish. In 1924 'under a large river-gum on the banks of the Burnett', she married fellow medical graduate, Ian Murray Mackerras. A resident year at Royal Prince Alfred Hospital followed and medical practice in Sydney. In 1925 she and Ian published a paper on blood parasites in fish, the first of 23 joint papers. On the birth of their only child, David, in 1926 Jo retired 'with increasing dissatisfaction' into domesticity.
They moved to Canberra when Ian joined CSIR's Division of Economic Entomology in 1929. Jo was appointed junior research officer in the same Division in October 1930. She worked on blowfly control in sheep, life histories of blowflies, and tick-borne fevers in cattle; an experimental study with Ian of ephemeral fever in cattle left 'no loose ends'. Jo enlisted in November 1941 and in 1943 joined Ian at the Land Headquarters Medical Research Unit in Cairns, where she was promoted to major and began research into malaria control by suppressive drugs, work of urgent strategic importance. With composure and ingenuity she led a team of soldier scientists in the experimental infection of over 1000 soldier volunteers with New Guinea strains of malarial parasites. When supplies of anopheline larvae from Papua failed she contrived a brilliant laboratory breeding program. Her most trying experience was standing by for 24 hours with insecticide to destroy her mosquitoes - a species not established in Australia - when a hurricane threatened the building. She later published much new information about anopheline mosquitoes and malarial parasites.
Discharged in 1946 she worked with Ian at CSIR laboratories, Yeerongpilly, in a position not commensurate with her ability. In mid 1947 Ian became Director and she parasitologist, later senior parasitologist, to the Queensland Institute of Medical Research. In epidemiology she investigated salmonella, scrub typhus, malignant tertian malaria, hookworm, amoebiasis, encephalitis and filariasis; she instigated improvements in hygiene, housing and water supplies at Aboriginal settlements and visited the Philippines, Malaya and New Guinea to discuss filariasis, leptospirosis and malaria. In entomology she worked mainly on blackflies with Ian. In parasitology she wrote a classic series of papers on blood and filarial parasites including four life histories, one being the complex cycle of the rat lungworm Angiostrongylus cantonensis. She and a colleague noticed that the lungworms could be separated into two kinds; the second was later named A. Mackerrasae after her.
In 1961 Jo and Ian retired to Canberra with CSIRO research fellowships. She wrote the chapter on cockroaches in Insects of Australia (1970); her main work was a comprehensive revision of the native Australian cockroaches of the family Blattidae. Failing health forced final retirement in 1968 and she died on 8 October 1971. Working at a time when government discriminated against the employment of married women and without the status she merited, under Ian's administrative umbrella Jo achieved high scientific stature. She was honoured with the Clarke Medal of the Royal Society of New South Wales, Fellowship of the Australian Society for Parasitology and DSc, Queensland. 'Plain, brilliant, adored by her husband' said a relative; 'and by everyone who knew her' added a colleague.
Patricia Morison
I. M. Mackerras and E. N. Marks The Bancrofts: a Century of Scientific Endeavour, Royal Society of Queensland Proceedings 84, 1972.