Aphytis melinus

Armored Scale Parasitoid

Contents:
5,000 · 10,000 · 20,000 · 30,000 adults for immediate release
Check contents upon arrival and report any issues at time of delivery.

Target Pests

(listed in order of preference)

• California red scale (Aonidiella aurantii)
  Citrus, roses, and ornamentals

• Ivy / Oleander scale (Aspidiotus nerii)
  Palms, cycads, and many ornamentals

• San Jose scale (Quadraspidiotus perniciosus)

• Walnut scale (Quadraspidiotus juglandregiae)

• Dictyospermum scale (Chrysomphalus dictyospermi)

Biology

Aphytis melinus is a tiny (≈1 mm), yellow parasitoid wasp specialized for controlling armored scale insects. Females lay eggs beneath the waxy scale covering, where larvae develop protected from environmental exposure.

• Parasitizes 2nd–3rd instar female scales and 2nd instar & pre-pupal male scales

• Adults also host-feed, killing additional scale stages beyond those parasitized

• Parasitized scales appear dried out and may show dark spotting

• At 80°F, development from egg to adult takes 13–17 days

• Adults live 10–15 days (up to 24), laying 6–7 eggs per day

• Active and effective between 60–85°F with ≥50% relative humidity

• Minimum release temperatures: 40°F night / 60°F day

• Begin flying at ~50°F; several hours above this are needed for egg laying

Use in Biological Control

Aphytis melinus is most effective when released early and regularly, starting at the first sign of scale activity in spring and continuing until populations are suppressed.

Orchards & Outdoor Plantings

• Release 1–2 cups per acre every other week until scale populations decline

• Distribute evenly: release parasites in every 6th tree, every 6th row, rotating rows weekly
  (~175 parasitoids per tree)

• Release on the shaded side of trees and when temperatures are below 90°F

• Parasites may be released by:

  • Leaving an opened cup in infested trees, or

  • Walking the orchard with an opened cup for faster dispersal

• Once control is established: ½–1 cup per acre annually in spring

• If scale pressure is high, apply a summer oil spray 2–3 weeks before release

Interior Plantings & Greenhouses

• Regular releases typically control infestations within 2–3 months

• Maintenance: 1–3 releases per year

• Guideline rates:

  • 5–10 parasitoids per infested plant, or

  • 10 parasitoids per square yard

• Release by gently waving an opened cup around infested plants

• Make 2–3 releases at 2–3 week intervals

• Release at dusk or under shaded conditions

• If scale populations are heavy:

  • Apply insecticidal soap 2–3 weeks before first release

  • Wash off honeydew just prior to release to improve parasitoid movement

Storage

• Use the same day of arrival whenever possible

• If short-term holding is necessary:

  • Store at approximately 60°F

  • Keep dark

• Do not refrigerate

• Do not place insects directly next to cold packs

• Viability declines rapidly with extended storage

Pesticide Compatibility

Compatible with:

• Horticultural oils

• Insecticidal soaps

• Bacillus thuringiensis (Bt)

• Sabadilla

If more toxic pesticides are applied, re-release Aphytis approximately 4 weeks later.