pest · saltwater tank

Red Bugs on Acropora

Red bugs (Tegastes acroporanus) are tiny copepod-like crustaceans that infest Acropora coral. Yellow-orange specks on the surface; cause polyps to retract and growth to slow.

Reviewed by Fast Aquatics husbandry team · Updated May 2026
Severity: Moderate - slows SPS growth, rarely fatal

Symptoms

What causes it

Hitchhiked in on un-dipped Acropora frags. Spread between Acropora pieces via water column.

Treatment options

Always treat in a separate quarantine tank.

Interceptor (milbemycin oxime). Veterinary heartworm medication used at 25 mg per 10 gallons. Effective in one dose for adults; second dose 7 days later for hatchlings. Toxic to crustaceans (CUC).
Bayer Advanced dip. Repeated coral dip every 5 days for 4-5 cycles to break hatch cycle.

Prevention

Dip every Acropora frag before placement. Quarantine new SPS for 30 days.

Frequently asked questions

What does Red Bugs on Acropora look like?

Tiny yellow-orange specks crawling on Acropora surface. Acropora polyps retracted or pale. Slow or stalled growth.

What causes Red Bugs on Acropora?

Hitchhiked in on un-dipped Acropora frags. Spread between Acropora pieces via water column.

How is Red Bugs on Acropora treated?

Interceptor (milbemycin oxime): Veterinary heartworm medication used at 25 mg per 10 gallons. Effective in one dose for adults; second dose 7 days later for hatchlings. Toxic to crustaceans (CUC).

Can Red Bugs on Acropora be prevented?

Dip every Acropora frag before placement. Quarantine new SPS for 30 days.

How fatal is Red Bugs on Acropora?

Moderate - slows SPS growth, rarely fatal

Related

Browse the full disease database for 45 aquarium conditions with treatment protocols, or check the care library for prevention-focused husbandry guides. Use our symptom matcher to rank likely diseases from observed signs, the water parameter checker to diagnose related water-quality issues, or the QT timeline calculator to plan a treatment schedule.