After the larvae of
Glyptapanteles sp. emerge, the caterpillar takes up position near the cocoons of the pupae, arches its back, and ceases to move or feed. It will occasionally spin silk over the pupae. However, when disturbed, it begins to thrash violently. No longer inclined to eat, the affected caterpillar eventually dies. It has been demonstrated in experimental research (Grosman, et al.) that this behavior is to strike at and repel possible predators of the pupae, such as the
shield bug Supputius cincticeps, thus improving their survival odds. Only about one in twenty non-parasitized caterpillars responded in this fashion. In 60% of cases, the parasitized caterpillars successfully warded off these potential predators. Mortality rates for pupae not guarded by parasitized caterpillars were significantly higher. That it is of no demonstrated benefit to the caterpillar indicates that this is an adaptation on the part of
Glyptapanteles.
Mechanism In the course of Grosman's research, it was discovered that not all larval
Glyptapanteles emerge from their caterpillar host; one or two remain behind. Grosman has theorized that these larvae manipulate the host, foregoing their own chance at pupating in order to protect the brood. ==Biocontrol==