Hummingbird hawk-moth

The Hummingbird hawk-moth (Macroglossum stellatarum) is a member of the Sphingidae family within the order Lepidoptera. While the adult moths are highly beneficial as pollinators, known for their ability to hover like hummingbirds, their larval stage (caterpillars) can occasionally act as pests on specific plant species.

The primary host plants for the larvae include members of the Rubiaceae family, most notably bedstraw (Galium spp.) and bedstraw-related species. In garden settings, these caterpillars can cause damage by feeding on the foliage of these plants, and in rare cases, they may infest related herbaceous ornamentals if natural food sources are depleted.

The life cycle undergoes complete metamorphosis, consisting of the egg, larval, pupal, and adult stages. Females lay individual eggs on the underside of host leaves. Upon hatching, the larvae begin feeding intensely. As they mature, they descend to the soil or leaf litter to pupate, where they typically overwinter as pupae until the following season.

Damage is characterized by the consumption of leaf tissue, which can range from minor chewing to significant defoliation of the host plant. While the Hummingbird hawk-moth is rarely classified as a major agricultural threat, large populations can weaken plants, inhibit their growth, and diminish the overall aesthetic value of a garden or nursery bed.

Effective management strategies focus on both cultural and chemical control. Key measures include:

• Implementing regular weeding programs to remove host plants like bedstraw from the vicinity of valuable crops.
• Monitoring plants for early signs of leaf damage during the active growing season.
• Manual removal of larvae in small-scale plantings to keep populations in check.
• Application of biological controls, such as Bacillus thuringiensis, if infestation levels exceed acceptable thresholds.