Guy L. Bush (1929–2023) was an evolutionary biologist, entomologist, and John Hannah Distinguished Professor at Michigan State University.
[5] Bush spent formative years in Brazil, attending high school in Rio de Janeiro and spending a summer working at a lab in the Brazilian interior.
[5] Many of his summers were spent doing field work in Door County, Wisconsin, where he and his students studied the fruit flies (family Tephritidae) that live in the localorchards.
While Mayr was skeptical of the possibility of sympatric speciation, Bush’s research on the apple maggot fruit fly is considered to provide a particularly strong case for that process, one that continues to be built upon by later workers.
On his death in 2023, Kay Holekamp, a behavioral ecologist and later director of the EEB program at MSU, said of Bush: "He was a real prince of a human being, super smart, and inspirational in his development of the Rhagoletis system to study sympatric speciation.