Overview
Hemp loopers are caterpillars belonging to moth species in the family Noctuidae, known for their distinctive looping movement and their ability to damage cannabis plants. These larvae are considered defoliators, feeding on leaves and reducing the plant’s photosynthetic capacity. While not exclusive to hemp, certain looper species readily infest cannabis crops, particularly in outdoor or greenhouse environments.
The name “looper” comes from the caterpillar’s unique method of movement, in which it arches its body to bring its hind legs forward before extending again. This looping motion distinguishes them from other caterpillars and is a key identification feature.
Hemp loopers are especially problematic during the vegetative stage of plant growth, when leaf mass is critical for development. Heavy infestations can strip plants of foliage, slowing growth and reducing yields.
Identification
Hemp loopers are green caterpillars that blend well with plant foliage. They typically measure 1–2 inches when fully grown.
They have fewer prolegs than most caterpillars, which contributes to their looping movement. Their coloration may include faint stripes or markings.
Habitat
These pests are found in agricultural fields, gardens, and greenhouses. They prefer environments where host plants are abundant.
They are most active during warm seasons.
Behavior and Life Cycle
Adult moths lay eggs on host plants. After hatching, larvae begin feeding immediately on leaves.
They pass through several developmental stages before pupating in soil or plant debris. Multiple generations may occur per season.
Damage and Impact
Hemp loopers cause defoliation by consuming leaf tissue. Severe infestations can strip plants of foliage, reducing growth and yield.
Damage may also increase plant susceptibility to disease.
Prevention and Control
Monitoring for early signs of feeding is essential. Hand removal, biological controls, and maintaining plant health can reduce impact.
Taxonomy
- Kingdom: Animalia
- Phylum: Arthropoda
- Class: Insecta
- Order: Lepidoptera
- Family: Noctuidae