Mahogany webworm

Definition

The larval stage or common name for Macalla thyrsisalis, a pyralid moth whose caterpillars spin silk webs on mahogany (Swietenia) and related meliaceous trees, skeletonizing foliage and sometimes causing significant defoliation in tropical hardwood plantations and native forests.

Etymology

From the host plant mahogany (Swietenia spp., Meliaceae) and the larval habit of constructing communal silk webs.

Example

In southern Florida, mahogany webworm outbreaks can defoliate young Swietenia mahagoni plantings, with larvae weaving dense silk shelters that protect them from predators and contact insecticides.

Synonyms

• mahogany webworm moth (adult)
• Macalla thyrsisalis

Related Terms

• Pyralidae
• snout moth
• leaf skeletonizer
• silk web
• Swietenia
• Meliaceae
• defoliator

Usage Notes

The name refers primarily to the larval stage; adults are typically called mahogany webworm moths. Not to be confused with other mahogany-feeding Lepidoptera such as the mahogany shoot borer (Hypsipyla spp., Pyralidae). The common name is used mainly in forestry and plantation entomology in the Caribbean and Central America.