April 2, 2011
Yoel Margalith, a biologist who discovered a natural, environmentally friendly pesticide to use against mosquitoes, dies at 78.
Margalith was born in February 1933 in Cantavir, Yugoslavia (now in Serbia). After the Nazis occupied Cantavir in 1942, the Margalith family was deported to Bergen-Belsen, then moved to Theresienstadt. Surviving the Holocaust, Margalith and his mother and sister immigrated to Israel in 1948.
Settling in Jerusalem, he became involved with science and nature, first working at the Jerusalem Biological-Pedagogic Institute and the Biblical Zoo. He received a master’s and a doctorate at Hebrew University, where he researched the physiology of rat fleas and the biology of tsetse flies. After teaching in the United States, Margalith returned to Israel in 1976 to work at the Israel Institute for Biological Research. In 1978 he became a professor and researcher at Ben-Gurion University of the Negev in Be’er Sheva, where he created and directed the Center for Biological Control.
In 1976, Margalith discovered a bacterium that is lethal to most mosquitoes and black flies. Bacillus thuringiensis israelensis (Bti) released crystals that are toxic when ingested by mosquito larvae. This natural pesticide controls mosquito populations without harming the environment or other species and is usually much cheaper than chemical pesticides.
Margalith was awarded the prestigious Tyler Prize for Environmental Achievement in 2003 because his discovery “has had an enormous effect on human health and on environmental quality.” In addition to the life-saving reduction of malaria by controlling mosquitoes, Bti preserved the eyesight of millions of people in 11 African countries by preventing river blindness.
He received numerous other honors and awards over the course of his career. He also used his scientific knowledge in the peace process, establishing multinational research and work groups to control mosquitoes and flies in the areas of the Palestinian Authority, Jordan and Israel.
