Complex sentence: The host plants of this species almost always carry toxins known as Pyrrolizidine alkaloids, and to deal with this the caterpillars have developed the capacity to metabolize a wide range of toxins using unique enzymes.
Split into simpler sentences: The host plants of this species almost always carry toxins known as Pyrrolizidine alkaloids. To deal with this the caterpillars have developed the capacity to metabolize a wide range of toxins using unique enzymes.