Worms Eating Petunias

Tobacco budworms are serious petunia pests.

Petunias (Petunia x hybrida) are perennials from the nightshade family. The funnel-shaped flowers bloom in a wide range of colors from spring to winter. Petunias grow well in full sun and well-drained soil. The plants are susceptible to worms that feed on and damage plants.

Identification

The University of Colorado Extension cites the tobacco budworm caterpillar as the most frequent petunia pest. The pests are small, green worms that infest petunias during summer. Tobacco budworms reach maturity in a month. The worms go through two generations in a year.

Damage

Tobacco budworms infest the developing flowers and their ovaries. Infested buds either do not bloom at all or are colorless and have chewed petals. The damage increases in intensity, reaching its peak in late summer. The worms also feed on the foliage, creating holes and giving the leaves an overall ragged appearance.

Management

Use synthetic pyrethrins to control the pests. Bacillus thuringiensis, which kills the insects upon ingestion, is a biological control option. Use resistant varieties to minimize loss.

References

• University of California Extension: Petunia
• Colorado State University Extension: Petunia