Pest identification
What's eating my broad-leaf horncone?
Armored scale (Diaspididae)
Signs: Hard shells clinging to caudex and leaf undersides; frond yellowing, dieback, and sticky honeydew
Control: Scrub off manually with alcohol; drench soil with systemic imidacloprid; repeat horticultural oil applications
Mealybugs (Pseudococcus spp.)
Signs: White waxy colonies in crown and leaf axils; sooty mold on honeydew; weakened emerging fronds
Control: Alcohol swabs for spot removal; insecticidal soap or neem oil spray every 7–10 days until clear
Spider mites (Tetranychus urticae)
Signs: Leaflet stippling and fine webbing, especially on indoor specimens in dry air
Control: Increase humidity and air circulation; rinse foliage; apply neem oil or miticide weekly for 3 weeks
Fungus gnats (Bradysia spp.)
Signs: Larvae damage shallow roots and caudex in moist, peaty potting mixes
Control: Allow soil surface to dry between waterings; use sticky yellow traps; apply Bacillus thuringiensis israelensis (Bti) drench
Keep broad-leaf horncone pest-free
Healthy plants resist pests best. Get the basics right:
Broad-leaf Horncone pests — FAQ
What is eating my broad-leaf horncone?
Broad-leaf Horncone is a Mexican cycad grown indoors or in warm-climate gardens. Scale insects are the most serious cycad pest, colonizing the stem and fronds. Mealybugs settle in the crown, and spider mites attack in dry conditions. Outdoors in humid climates, fungus gnats may trouble potted specimens. Inspect at every watering.
How do I get rid of armored scale (diaspididae) on broad-leaf horncone?
Hard shells clinging to caudex and leaf undersides; frond yellowing, dieback, and sticky honeydew Scrub off manually with alcohol; drench soil with systemic imidacloprid; repeat horticultural oil applications
How do I get rid of mealybugs (pseudococcus spp.) on broad-leaf horncone?
White waxy colonies in crown and leaf axils; sooty mold on honeydew; weakened emerging fronds Alcohol swabs for spot removal; insecticidal soap or neem oil spray every 7–10 days until clear
How do I get rid of spider mites (tetranychus urticae) on broad-leaf horncone?
Leaflet stippling and fine webbing, especially on indoor specimens in dry air Increase humidity and air circulation; rinse foliage; apply neem oil or miticide weekly for 3 weeks
How do I get rid of fungus gnats (bradysia spp.) on broad-leaf horncone?
Larvae damage shallow roots and caudex in moist, peaty potting mixes Allow soil surface to dry between waterings; use sticky yellow traps; apply Bacillus thuringiensis israelensis (Bti) drench