Field Identification
A tropical-temperate armyworm that skeletonizes leaves, bores into heads, and riddles lettuce, peppers, and ornamentals; larvae web frass and debris like unpleasant tent caterpillars for salad greens.
Smooth-bodied green to black caterpillars with a prominent black spot on each side of the body above the second pair of true legs; adults are mottled gray-brown moths.
How to Deal With It
Organic Control Methods
Bt aizawai or kurstaki on small larvae; spinosad for tougher instars—penetrate webbed feeding shelters with directed spray.
Nuclear polyhedrosis viruses occur naturally in outbreaks; parasitoids and predators build after initial flare—avoid nuking the whole field.
Disk or remove residue after harvest; manage weeds that are Spodoptera hosts; avoid staggered lettuce that bridges generations.
Hand picking in gardens; flush larvae from crowns with directed water then collect.
Pheromone monitoring in commercial settings; scout for egg masses and early webbing.
Let Nature Handle It
Natural Enemies
- Ichneumonid and braconid parasitoids
- Tachinid flies
- Predatory beetles