Complex sentence: Though lantanas are generally hardy and, being somewhat toxic, usually rejected by herbivores, they may still become infested with pests, though pest control insecticidal soaps are harmful to these plants.
Split into simpler sentences: Though lantanas are generally hardy and, being somewhat toxic, usually rejected by herbivores, they may still become infested with pests. In pest control, be aware that insecticidal soaps are harmful to these plants.