Pest identification
What's eating my centennial hops?
Two-spotted spider mite (Tetranychus urticae)
Signs: Yellow stippling then bronze or grey cast to leaves; fine webbing under leaves; serious defoliation reduces cone size and alpha acid content.
Control: Release predatory mites early in the season; use overhead irrigation in dry spells; apply abamectin or bifenazate at threshold; avoid carbamate insecticides that flare mite populations.
Hop aphid (Phorodon humuli)
Signs: Colonies on tender shoot tips and in developing cones; honeydew contamination renders cones unsaleable for brewing.
Control: Encourage natural enemies (lacewings, parasitic wasps); use insecticidal soap or neem oil on early colonies; reflective mulch repels winged migrants.
Japanese beetle (Popillia japonica) — US only
Signs: Skeletonized leaves with intact veins remaining; adults aggregate and feed communally, intensifying damage.
Control: Hand-pick morning adults into soapy water; apply Bt galleriae or neem oil; introduce milky spore to lawn areas to reduce grub populations long-term.
Keep centennial hops pest-free
Healthy plants resist pests best. Get the basics right:
Centennial Hops pests — FAQ
What is eating my centennial hops?
Centennial hops share the same pest complex as all Humulus lupulus cultivars. Spider mites are the single most damaging pest, causing bronze foliage and cone loss in hot, dry summers. Hop aphids foul cones with honeydew. Japanese beetle skeletonizes leaves across much of the eastern US. Consistent mite monitoring from July onward is essential.
How do I get rid of two-spotted spider mite (tetranychus urticae) on centennial hops?
Yellow stippling then bronze or grey cast to leaves; fine webbing under leaves; serious defoliation reduces cone size and alpha acid content. Release predatory mites early in the season; use overhead irrigation in dry spells; apply abamectin or bifenazate at threshold; avoid carbamate insecticides that flare mite populations.
How do I get rid of hop aphid (phorodon humuli) on centennial hops?
Colonies on tender shoot tips and in developing cones; honeydew contamination renders cones unsaleable for brewing. Encourage natural enemies (lacewings, parasitic wasps); use insecticidal soap or neem oil on early colonies; reflective mulch repels winged migrants.
How do I get rid of japanese beetle (popillia japonica) — us only on centennial hops?
Skeletonized leaves with intact veins remaining; adults aggregate and feed communally, intensifying damage. Hand-pick morning adults into soapy water; apply Bt galleriae or neem oil; introduce milky spore to lawn areas to reduce grub populations long-term.