Dendrobium orchid pests, webbing or sticky leaves: causes and what to do
6 results in the diagnosis tree begin with pests, 5 of them marked likely when the answers fit. They are ordered here for Dendrobium orchid (Dendrobium nobile), using what its sources say about pests and diseases, humidity and watering and 3 problems recorded for it.
Sources last read 14 September 2026.
Dendrobium nobile, also known as the noble dendrobium, is a member of the family Orchidaceae. It is one of the most widespread ornamental members of the orchid family. Wikipedia, CC BY-SA 4.0
Native range: Nepal to S. China and Indo-China (subtropical). Also sold as noble rock orchid.
What Dendrobium orchid’s sources say that bears on this
- Pests and diseases
- Can be troubled by mealybugs, greenhouse red spider mite and aphids. Diseases: usually none.RHS · read 13 September 2026
- Humidity
- ASHRAE recommends indoor relative humidity between 30% and 60%Penn State Extension · read 13 September 2026
- Watering
- Use epiphytic orchid potting mix. From late spring through summer, keep in partial shade with good airflow, daytime temperatures of 18-25°C and nights above 10°C; water generously, add orchid fertiliser at every third watering, and mist twice a day for high humidity.RHS · read 13 September 2026
How this shows up on a Dendrobium orchid
Fine pale speckling on the leaves, then webbing at the tips: spider mites
The leaves of the dendrobium orchid lose their shine and fill with tiny pale dots. In a heavy infestation fine webbing strings across the shoot tips.
RHS lists spider mites among the pests it may attract. They feed from the underside, so the damage shows on top long before the mites are noticed.
Telling it apart: Tap a leaf over white paper. Dots that crawl are mites; dust stays still.
RHS · read 13 September 2026Sticky buds and shoot tips crowded with small insects
The youngest growth of the dendrobium orchid is sticky and distorted, and a closer look finds colonies of small, pear-shaped insects.
RHS lists aphids among the pests it may attract. They feed on the sap of soft new growth, which distorts it, and they multiply quickly without mating.
Telling it apart: What the white bits are. Aphids leave papery cast skins; mealybugs leave wax with an insect inside.
RHS · read 13 September 2026Sticky leaves and white fluff where they meet the stem: mealybugs
The dendrobium orchid carries white, cottony specks in its crevices, and growth slows. Leaves beneath the colonies turn sticky and, in time, dull or yellow.
RHS lists mealybugs among the pests it may attract. They feed on sap and shed the excess as sticky honeydew, and a colony tucked into the joints spreads before it is noticed.
Telling it apart: Where the white is. Mealybugs gather in joints and under leaves; a powdery coating across the top of a leaf is mildew.
RHS · read 13 September 2026Possible causes, likeliest first for a Dendrobium orchid
Most likely spider mites
Ranked higher because Dendrobium orchid's recorded problems point this way.
- Fine pale speckling on the leaves, then webbing at the tips: spider mites RHS
Why: Spider mites feed on individual leaf cells, and each emptied cell shows as a pale speck.
What to try:
- Move the dendrobium orchid away from other plants.
- Wash the leaves, top and underside, with a strong spray of water in a shower or sink.
What would settle it: Hold a sheet of white paper under a leaf and tap the leaf. Tiny specks that move across the paper are mites.
Most likely mealybugs
Ranked higher because Dendrobium orchid's recorded problems point this way.
- Sticky leaves and white fluff where they meet the stem: mealybugs RHS
Why: Mealybugs are soft insects that cover themselves in white wax, which gives the cottony look.
What to try:
- Move the dendrobium orchid away from other plants.
- Wipe off every insect you can see with a cotton swab dipped in rubbing alcohol, testing a single leaf first.
What would settle it: Touch a tuft with a cotton swab. If a small, pale, oval insect is underneath, it is a mealybug.
Most likely aphids
Ranked higher because Dendrobium orchid's recorded problems point this way.
- Sticky buds and shoot tips crowded with small insects RHS
Why: Aphids cluster on soft new growth and flower buds, where the sap is easiest to reach.
What to try:
- Rub them off with fingers, or rinse them off in a sink or shower.
- Repeat every few days while new ones appear.
What would settle it: Look for the pale shed skins among the insects. Aphids molt as they grow, and the skins are left behind in the colony.
Less likely for a Dendrobium orchid, still possible
Questions
- What usually causes pests on a Dendrobium orchid?
- For Dendrobium orchid: spider mites, mealybugs and aphids.
- How can I tell which one it is on my Dendrobium orchid?
- What can you see? Fine webbing, and tiny pale speckles on the leaves; White, cottony tufts in the leaf joints; Small brown or pale bumps on stems and leaves that do not move; Clusters of small, soft insects on the new growth; Tiny dark flies around the soil; Sticky, shiny residue, but no insect I can see.
- What do Dendrobium orchid's sources say about its pests and diseases?
- RHS: Can be troubled by mealybugs, greenhouse red spider mite and aphids. Diseases: usually none.
- What does this look like on a Dendrobium orchid?
- The leaves of the dendrobium orchid lose their shine and fill with tiny pale dots. In a heavy infestation fine webbing strings across the shoot tips. Telling it apart: Tap a leaf over white paper. Dots that crawl are mites; dust stays still.
Other plants that show pests
African violetIrregular notches bitten from leaf edges by an insect pest
Barberton daisyCurled, sticky new leaves with green or black insects: aphids
Bearded irisRagged holes and slime trails: a slug or snail pest
Bigleaf hydrangeaClusters of small soft insects on the shoot tips and buds: aphids
Bird of paradiseDull, finely mottled leaves and faint webs: spider mites
Blue passion flowerPale stippled leaves and tiny moving dots underneath: a mite pest
Something else wrong with the Dendrobium orchid?
What this does not cover
This page orders a decision tree's results using a plant's sourced care. It has not seen your plant, its pot or its window, and two problems at once are common: that is the usual reason a confident answer turns out wrong. The questions in the diagnosis tool narrow it further than a list can.