**Honeysuckle Sawflies** (*Zaraea inflata*) are insects whose larvae are severe defoliating pests of **honeysuckle** (*Lonicera* spp.). The larvae (which resemble caterpillars but are related to wasps) feed voraciously on the leaves, capable of stripping the foliage from entire shrubs or vines in a matter of days. Their damage is purely aesthetic but can severely stress landscape plants, particularly common in the northern and eastern United States.
Taxonomy and Classification
Honeysuckle Sawflies belong to the order Hymenoptera (wasps, bees, ants), family Cimbicidae. They undergo complete metamorphosis. Sawfly larvae are often confused with moth caterpillars but can be distinguished by the number of prolegs (fleshy abdominal legs): sawflies have six or more pairs, while true caterpillars have five or fewer pairs.
Physical Description
Adult Sawflies are stout, black and yellow, non-stinging insects that resemble small, clumsy wasps.
- **Larvae (The Pest Stage):** Highly distinctive, up to 1.5 inches long, with a light green or whitish-green body covered in small, black, pin-like spines. They often curl into a tight ball when disturbed.
- **Feeding:** Larvae skeletonize the leaves, consuming all tissue except the main veins.
- **Behavior:** They are gregarious (feed in groups or clusters) and often position themselves symmetrically around the edge of a leaf, feeding inward.
- **Pupation:** They overwinter as pupae in tough, cocoon-like casings in the leaf litter or soil near the base of the plant.
Distribution and Habitat
Honeysuckle Sawflies are common in the eastern and midwestern U.S. and Canada. Their habitat is ornamental and wild honeysuckle plants. The larvae are active during the mid-to-late spring and early summer, targeting the newly developed foliage.
Behavior and Conflict
The primary conflict is the sudden, rapid defoliation of the host plant.
- **Voracious Feeding:** Because they feed gregariously and quickly, a large population can strip an entire honeysuckle shrub bare within days, often before the damage is noticed.
- **Stress to Plant:** While honeysuckle is generally tough and will put out new leaves later in the season, the defoliation causes significant stress, especially if it occurs repeatedly or during a drought.
- **Aesthetic Loss:** The sudden loss of leaves severely impacts the plant’s ornamental value during its peak season.
Management and Prevention
Control is highly effective if implemented immediately upon detection of the first larvae.
- **Monitoring:** Inspect honeysuckle foliage frequently in spring for signs of initial feeding (holes in leaves).
- **Manual Control:** Due to their clustered feeding habit, the larvae can be easily removed by hand-picking and destroying them, or by cutting off the infested branch and discarding it.
- **Targeted Insecticide:** Effective control can be achieved with low-impact materials:
- **Insecticidal Soap/Horticultural Oil:** Effective against young larvae.
- **Pyrethrins:** Provide fast knockdown.
- **Note:** Unlike moth caterpillars, sawfly larvae are **not** affected by *Bacillus thuringiensis* (Btk) because they are Hymenoptera.
- **Sanitation:** Raking and disposing of leaf litter beneath the plant in late fall or early spring can help destroy some overwintering pupae.
Conservation and Research
Honeysuckle Sawflies are managed as ornamental pests. Research focuses on understanding the chemical cues that limit them to their *Lonicera* host and evaluating natural enemies for use in landscape IPM programs.