Pest identification
A working reference for the rose pests we see on Woodrow Circle. Built for an experienced grower — identification first, then damage, life cycle, and treatments organic-to-chemical. Updated as Birgit photographs new examples in the garden.
High & severe
Aphids
Macrosiphum rosae & Macrosiphum euphorbiae (rose aphid; potato aphid)
Soft-bodied, pear-shaped insects in clusters on new growth and buds. The single most common rose pest — usually the first to appear in spring.
Japanese Beetle
Popillia japonica
Half-inch metallic-green-and-copper beetles that arrive in June–July, feed in groups, and skeletonize leaves and petals.
Two-Spotted Spider Mite
Tetranychus urticae
Microscopic mites that explode in hot, dry weather. The first sign is a faint stippling on leaves; by the time you see webbing it is already serious.
Western Flower Thrips
Frankliniella occidentalis
Slender, almost-invisible insects that hide deep in opening blooms and rasp the petals. Pale and white-flowered roses suffer most.
Rose Midge
Dasineura rhodophaga
A tiny fly whose larvae kill rose buds before they open. The classic symptom: every new bud blackens and falls off.
Moderate
Rose Slug (Sawfly Larvae)
Endelomyia aethiops; Cladius difformis; Allantus cinctus
Tiny, slug-like larvae that skeletonize rose leaves in spring. Despite the name they are larvae of small, non-stinging wasps.
Rose Scale
Aulacaspis rosae & Diaspidiotus perniciosus
Small immobile insects that look like crusty white or brown bumps welded onto canes and the undersides of leaves.
Rose Leafhopper
Edwardsiana rosae
Slender, fast-moving white-yellow insects that scatter when you brush a cane. Their feeding speckles leaves and they vector phytoplasma diseases.
Rose Curculio
Merhynchites bicolor
A bright red-and-black snout weevil that drills holes through buds and chews shoot tips. Distinctive in person, easily missed by symptom.
Greenhouse Whitefly
Trialeurodes vaporariorum & Bemisia tabaci
A snowstorm of tiny white moth-like insects that lifts off when you brush a leaf. More common on greenhouse-grown roses than outdoor.
Tobacco Budworm
Chloridea virescens
Caterpillars that bore directly into rose buds and feed inside. You don't see them — you find chewed buds with frass at the base.
Low
Rose Cane Borers
Several wasps & sawflies; e.g. Hartigia trimaculata; small carpenter bees
Pith-eating insects that tunnel down the center of cut canes. The classic sign: a hole in the middle of every pruning cut.
Citrus Mealybug
Planococcus citri
Cottony white tufts in leaf axils and on canes. More problematic on potted/greenhouse roses than outdoor.
Mossy Rose Gall Wasp
Diplolepis rosae & Diplolepis polita
Striking, mossy-pink "Robin's pincushion" growths on canes. More curiosity than threat.
Treatments listed organically before chemically. As an experienced grower, Birgit will know when each rung of the ladder is appropriate. When in doubt, the Texas A&M AgriLife Extension office and the American Rose Society Consulting Rosarians are excellent second opinions.