The Delta is a science fiction novel by English writer Colin Wilson, published in 1987.
The novel's main protagonist, Niall, heads for the Delta to investigate the source of a vital spiritual force which causes insects to grow large. [1]
David Langford, reviewing The Delta for White Dwarf #100, stated that "The Delta is better than promised by The Tower, but the crudeness of its SF tropes detracts from the more interesting Wilson philosophy." [1]