Eliminating Fungus Gnats from a Coral Cactus (Euphorbia lactea crest)

Small flies at the soil base that rise when watering are fungus gnats. Adults are harmless, but larvae feed on fine roots in moist, organic soil. Isolate the plant immediately.

Control: hang yellow sticky traps for adults; let soil dry completely to kill larvae; spray neem oil on soil surface and plant. After resolution (2–3 weeks), repot in sterile soilless mix (peat, vermiculite, perlite) and keep dry. Coral cacti and other succulents need minimal water—overwatering invites gnats, rot, and mealybugs.

Fungus gnats thrive in humid summers with organic soils. Dry conditions and sterile media prevent recurrence.