The Venom of Argus - Novel 1976
This is Book Four of Four in the series called 'The Expendables'. He wrote this series using the pseudonym 'Richard Avery'.
They were THE EXPENDABLES - some genuine volunteers, others not. They were the chosen ones - the people who had been 'selected' to travel far into space and find new planets for human colonisation.
The Expendables go to Argus and encounter a deadly hallucinogenic pollen which turns the quiet 'Santa Maria' crew members into vicious maniacs.