What's eating my humboldt's bladderwort?

Utricularia humboldtii is an epiphytic bladderwort from South American bromeliads, grown in sphagnum or water-filled containers indoors. Fungus gnats colonise the wet substrate or standing water and are the dominant pest. Algae is a persistent co-problem in bright light. Aphids occasionally attack the impressive, large flower scapes this species produces.

Adults swarm around the wet growing medium; larvae damage delicate stolons and root-like structures in the sphagnum or water medium. Yellow sticky traps at pot height catch adults effectively. Refresh water in the bromeliad tank or tray regularly. A sand cap on any exposed sphagnum surface limits oviposition.

In the high-light conditions required for flowering, green algae colonise water surfaces and pot walls, reducing available light and nutrients. Use opaque or dark-coloured containers. Change standing water every 3–5 days. Keep the growing space well-ventilated to slow algal growth.

Clusters appear on the tall, distinctive flower scapes, distorting blooms and potentially spreading to nearby plants. Spot-treat with an isopropyl alcohol swab. Because the scapes are large and few, manual removal is very effective — treat at first sighting.