An even more remarkable story of biological control is the spongy moth (previously called the gypsy moth).
https://biocontrol.entomology.cornell.edu/success.php
"The tale of the gypsy moth is intriguing on several levels, including its mysterious control by a fungus (Hajek 2007). Originally brought to the US to breed with the native silkworms, the gypsy moth, Lymantria dispar L., escaped through a broken window in Medford, MA in 1868-9 and began defoliating deciduous forests and shade trees in many regions of North America. High populations of this pest are uncommon in areas where it has long been established (Europe, northern Africa and temperate Asia), but outbreaks have occurred where gypsy moth has invaded without its natural enemies. Fungal infected gypsy moths were found in Japan and brought back and released in the Boston area in 1910-11, but apparently didn’t take. By 1997, dozens of other natural enemies were also released but none provided effective control.
In the late 1980s and early 1990s, scientists noticed gypsy moth cadavers hanging from trees in the northeastern forests and identified the cause as a fungal infection. This discovery renewed interest in using fungi for control. Molecular studies indicated that the infection was caused by the same species of fungus, Entomophaga maimaiga, as the one collected in Japan in the early 1900’s, but that it was not identical to that fungus or to the same species collected and released in 1985-86. When and where did it come from and how was it spread? The answer seems that it was an accidental introduction from Japan and probably occurred after 1971. Perhaps even more interesting is that fact that it has spread across the contiguous distribution of the gypsy moth in the Northeastern US. This spread is due to aerial dispersal of spores from gypsy moth larvae and perhaps to human activity, as gypsy moths are prone to move long distances on the undersides of vehicles. There is interest in using infected gypsy moth, or the fungus itself, to inoculate the leading edges of newly infested areas and prevent outbreaks of this devastating pest. However, details of the introduction and establishment of US populations of E. maimaiga remain a mystery."