NC State Extension Publications

Description and Biology

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The southern purple mint moth, Pyrausta laticlavia, is a native species with a wingspan of 3/4 inch. It is a typical snout moth (the palps stick out in front) with reddish-purple wings marked with brownish-yellow bands. In some specimens the purple areas may be brown. Little has been published on the biology of this insect. Moths must lay eggs from which hatch tiny caterpillars. Older caterpillars are pale to green, are relatively slender and have rows of black spots down the back and sides. The caterpillars spin loose webbing as they feed. The webbing accumulates pellets of frass. Pupae are dark brown, slender, and taper at both ends. They are found in the silk webbing. These moths fly from June to August. We probably have several generations per year in North Carolina.

Southern purple mint moth

Southern purple mint moths are triangular shaped when at reat.

Southern purple mint moth caterpillar

Southern purple mint moth caterpillars are small, slender, and damaging to rosemary.

likely the caterpillar of the southern purple mint moth

This is most likely the caterpillar of the southern purple mint moth.

Pupa

Pupae of southern purple mint moths are slender and brown.

Host Plants

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Caterpillars of the southern purple mint moth have only been reported feeding on rosemary, Rosmarinus officinalis. The mint-loving pyrausta moth, Pyrausta acrionalis, is a similar species that feeds on mints in the genus Mentha. It has deep rose to violet forewings with yellow borders along the leading edge and the fringes of the wing, as well as some mottled yellow markings.

rosemary look awful

Southern purple mint moth caterpillars can make rosemary look awful.

Residential Recommendations

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If rosemary is for culinary use, it would be well to use insecticidal soap or insecticides with Bacillus thuringiensis as the active ingredient.

Other Resources

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For assistance with a specific problem, contact your local Cooperative Extension Center.

This Factsheet has not been peer reviewed.

Author

Professor Emeritus
Entomology & Plant Pathology

Publication date: Nov. 4, 2019
Revised: Nov. 4, 2019

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