- Eggs: Females use a saw-like apparatus at the tip of their abdomen to slit the underside of host leaves where they lay their eggs which hatch about a month later.
- Larvae: Larvae may resemble caterpillars (pine sawfly) or slugs (pear sawfly, rose slug). The majority of sawflies feed on conifer foliage and overwinter in the ground or on conifer trees.
- Pupae: Some sawflies pupate in the spring; others remain in different pupa stages for 2 or 3 years (known as diapause).
- Adults: Adult sawflies appear in early summer and look like a small bee.
- Tree defoliation: Sawfly larvae feed in colonies and eat the upper side of leaves. This causes the leaves to brown and then fall to the ground.
- Preventive tools:
- Follow a regular watering, fertilizing, and pruning schedule to keep your plants as healthy as possible to resist attack
- Physical tools: Not applicable
- Biological tools: Not applicable
- Least toxic chemical tools: Not applicable