Bertha armyworm

Definition

A noctuid moth (Mamestra configurata) whose caterpillars are significant agricultural pests in western North America, feeding on a broad range of crops including canola, mustard, alfalfa, and various vegetables. The common name reflects both the species' destructive larval aggregations typical of armyworms and its regional economic importance in Canadian prairie agriculture.

Etymology

From 'Bertha,' of uncertain origin (possibly a proper name), plus 'armyworm,' describing the caterpillars' habit of marching en masse to new food sources when local vegetation is depleted.

Example

In Alberta canola fields, Bertha armyworm outbreaks are monitored using pheromone-baited traps to time insecticide applications before fourth-instar larvae cause economic defoliation.

Synonyms

• Mamestra configurata

Related Terms

• Armyworm
• Noctuidae
• Cutworm
• canola pest
• pheromone trap
• Economic threshold
• larval instar

Usage Notes

The common name is regionally specific to North America; specialists use the scientific name Mamestra configurata. Not a true armyworm in the genus Spodoptera, but shares the descriptive term due to similar larval behavior. Adults are nondescript brown moths rarely noticed; damage is caused entirely by larvae.