The RHS hoya growing guide says to check hoyas regularly for sap-sucking insects: mealybugs, glasshouse whitefly and scale insects. Colorado State says mealybugs are swabbed with alcohol, scale is best treated with spray oils, and whiteflies are caught on sticky cards. The RHS also says overwatering or poor drainage causes dropping leaves, blackening and root rot, which can look like pest damage.
Pests and what the sources say
| Pest | Signs (Colorado State) | Controls described |
|---|---|---|
| Mealybugs | Sap feeding, leaf drop, honeydew, cottony egg masses | Swab with alcohol, or dilute alcohol or soap; root-feeding stages are missed |
| Scale | Honeydew, dieback; spotting for armored scale | Spray oils most effective; picking or rubbing for small infestations; treat for two to four months |
| Whiteflies | Sap feeding, leaf drop, honeydew | Sticky cards, vacuuming on small plants |
Pest damage or watering problem?
The RHS lists dropping leaves, blackening, dieback and root rot as the result of overwatering or poor drainage, and says root rot often kills the plant. If the leaves are sticky or have cottony patches, look for pests; if the base is soft or black, check drainage. See Best Potting Mix for Hoya.
Cautions
Colorado State says to use only pesticides labeled for houseplants, that alcohol can burn leaves so test a small area first, and to quarantine new plants for at least three weeks. The RHS says hoya sap irritates skin, so wear gloves when handling. This page does not recommend chemical products.
What the sources do not cover
The RHS gives no hoya-specific controls. See Hoya Indoors for the hub.
Frequently asked questions
What pests attack hoya?
The RHS names mealybugs, glasshouse whitefly and scale insects.
How do I treat mealybugs on hoya?
Colorado State says swab with alcohol, or use dilute alcohol or insecticidal soap.
Is hoya safe for pets?
The ASPCA lists a Hoya carnosa cultivar called wax plant as non-toxic to dogs and cats.
Sources read for this page
Last reviewed 15 October 2026. Written by Md. Firozur Rahman. This page gives general guidance and cannot diagnose a plant from a description; see the Disclaimer.
Leave a Reply