Spinosyn D is the second most abundant component (comprising up to 15%) of the spinosyn fermentation complex of macrocyclic lactones. Spinosyn D is a more hydrophobic analogue, and is a potent insecticide for crop pathogens and ectoparasite control on animals, albeit less active than spinosyn A. The spinosyns have a unique mechanism of action involving disruption of nicotinic acetylcholine receptors.