Armyworm (likely a Western Yellow-striped Armyworm)

Grassy fields, agricultural lands, and gardens across the western United States

Broad-spectrum herbivore eating grasses, weeds, and various crops like alfalfa, tomatoes, and beans

Larvae are primarily active at night to avoid predators; they can 'march' in large groups when food sources are depleted

Risk: Major agricultural pest that can defoliate crops rapidly. Benefit: Provides a food source for birds and parasitic wasps