Zebra swallowtail

The zebra swallowtail (Eurytides marcellus) belongs to the family Papilionidae within the order Lepidoptera. While primarily recognized for its striking appearance, in an agricultural context, its larvae act as specialized herbivores that can negatively affect plants within the Annonaceae family, specifically pawpaw trees.

The primary host for this insect is the pawpaw (Asimina triloba). The caterpillars exhibit a narrow host range, which means that commercial pawpaw orchards are the primary sites where this insect may be considered a pest requiring management interventions to prevent crop damage.

The life cycle encompasses four distinct stages: egg, larva, pupa, and adult. The females lay eggs individually on the underside of host leaves. The larval stage is characterized by intense feeding behavior, progressing through several instars before the insect reaches the pupation phase in protected areas near the host plant.

The damage caused by Eurytides marcellus involves the consumption of leaf tissue, ranging from small notches to complete skeletonization of the leaves. In nursery settings or young plantations, this defoliation can stunt tree growth, decrease photosynthetic capacity, and compromise the vigor of the saplings.

Effective management strategies should focus on integrated pest management (IPM) practices. Monitoring for early larval stages allows for timely intervention. When necessary, biological controls, such as applications of Bacillus thuringiensis, provide an effective and environmentally friendly solution for managing infestations.

• Early season scouting for egg clusters on young foliage.
• Manual removal of caterpillars in small-scale plantings.
• Application of bio-rational insecticides during peak larval activity.
• Promotion of biodiversity to encourage natural predators like wasps.