Ichneumonidae (Ichneumon Wasps) are a parasitic family of wasps that (usually) lay their eggs on or into a host body (e.g. butterfly larvae/caterpillar). The caterpillar is the food source of the ichneumonidae larva once it hatches.
Charles Darwin discussed the ichneumonidae regarding his views on God and religion. He wrote, “I cannot persuade myself that a beneficent and omnipotent God would have designedly created the Ichneumonidae with the express intention of their feeding within the living bodies of Caterpillars.”
Darwin’s persuasion or lack thereof is simply another belief system of his own making. It has no bearing on whether there is a God, whether he is beneficent and omnipotent, or whether he created the ichneumonidae and the caterpillars upon which they live.