Asparagus Miner
Beginner
Scientific Names
Ophiomyia simplex
Identification
- Asparagus miner larvae create winding tunnels (mines) on the stalks just below the epidermis.
- The mines are normally found near the base of the plant.
- The larvae are pure white and range in size from 0.5-5 mm long.
- The adult is a small, shiny black fly, 2.5 to 3.5 mm in size.
Period of Activity
Miner adults emerge in early June. There are two generations per year, with peak populations normally occurring in mid-June and again in mid-August.
Scouting Notes
Carefully inspect 10 groups of 10 plants across the field. While scouting, look for the presence of mines at the base of the plants. Miner populations are most active in younger fields (less than 5-years old).
Thresholds
None established.
Advanced
Scientific Names
Ophiomyia simplex
Identification
Asparagus miner eggs are laid under the surface of the asparagus stalk. The larvae are pure white and range in size from 0.5–5 mm long. They eat the succulent green tissue directly under the epidermis, creating complex, twisting mines near the base of the plant. Young fields (less than 5-years old) are most susceptible to asparagus miner populations. The adult is a small, shiny black fly 2.5 to 3.5 mm in size.
Biology
Asparagus miner overwinter as pupae in crop residue and in the soil. The adults emerge in early-June, mate and lay eggs. Adults live for 4-5 days, producing only one flush of eggs. Depending on the temperatures, the eggs hatch in 12-17 days.
The first generation of larvae can be found in asparagus fields immediately after harvest through mid-July. First generation larvae feed for 2-3 weeks before they pupate.
The next generation of adults emerges in late-July or August. The peak feeding activity for second generation larvae occurs in late-August to September.
Period of Activity
Miner adults emerge in early June. There are two generations per year, with peak populations normally occurring in mid-June and again in mid-August.
Scouting Notes
Carefully inspect 10 groups of 10 plants across the field. While scouting, look for the presence of mines at the base of the plants. Miner populations are most active in younger fields (less than 5-years old).
Thresholds
None established.
Management Notes
- Miners are not usually associated with any significant plant injury or yield loss; however, they transmit Fusarium from infected plants to healthy ones.
- Several natural predators, including parasitic wasps, help to control asparagus miners in established plantings.
- Effective chemical control is difficult. The larvae are protected inside the stem and do not respond to foliar insecticides.
- Many of the chemical controls targeted at adult flies are largely ineffective due to the high mobility and short life-span of the fly.
