Common Raspberries pests

The most damaging pest is spotted wing drosophila (SWD), a small vinegar fly whose females lay eggs in ripening fruit, so berries look fine at picking but soften and collapse within a day or two as tiny white maggots feed inside. Raspberry cane borer is a slender long-horned beetle that makes two rings of punctures near a shoot tip, causing the top to wilt and blacken, while the larger raspberry crown borer tunnels into crowns and canes at the base and makes whole canes wilt and die. Watch also for aphids, which curl new leaves and, more importantly, transmit mosaic viruses; Japanese beetles that skeletonize leaves and chew fruit; and two-spotted spider mites that stipple and bronze foliage in hot, dry spells. Raspberry fruitworm beetles and their grubs feed on buds, leaves, and berries, while birds and deer are common vertebrate pests that strip fruit and browse tender canes.

Common diseases

Fungal cane diseases are the most frequent trouble: anthracnose shows as gray-centered purple spots on canes and leaves, spur blight produces brown-to-purple blotches around buds and nodes, and cane blight causes dark cankers that make fruiting canes wilt and snap. Gray mold (Botrytis) rots ripening and picked berries into fuzzy gray masses, especially in wet weather or crowded plantings. Orange rust, a systemic fungus most common on black and purple raspberries, coats leaf undersides in bright orange, powdery pustules in spring and permanently deforms the plant. Root and crown problems include Phytophthora root rot in wet soils and Verticillium wilt, while virus complexes (raspberry mosaic, raspberry bushy dwarf, and tomato ringspot) cause mottled leaves, stunting, and crumbly, poorly formed berries; crown gall bacteria can also form warty tumors on crowns and roots.

Prevention

Start with certified disease-free, virus-tested plants and choose varieties bred for resistance to the diseases common in your region, and keep new plantings away from wild brambles that harbor pests and viruses. Space rows and thin canes so sunlight and air move freely, which dries foliage and fruit and greatly reduces cane diseases and gray mold. Prune out and remove spent floricanes right after harvest and cut away any diseased canes, taking all trimmings out of the garden rather than composting them. Water at the base with drip or soaker hoses to keep leaves dry, mulch to suppress splash and weeds, avoid planting where tomatoes, potatoes, peppers, or eggplant recently grew to limit Verticillium, and plant in well-drained soil or raised beds to prevent root rot.

Organic control

Manage spotted wing drosophila with frequent, clean harvests every day or two, prompt refrigeration of picked fruit, removal of overripe and dropped berries, and fine mesh exclusion netting over plants as fruit begins to color; an OMRI-listed spinosad product used according to its label can help during heavy pressure. Hand-pick Japanese beetles and cane borer tips into soapy water in the morning, prune out and destroy wilted borer-infested tips, and knock back aphids and mites with a strong water spray or insecticidal soap while encouraging lady beetles, lacewings, and predatory mites. Neem-based products can suppress soft-bodied pests, and floating row covers exclude beetles before bloom, but remove covers during flowering so pollinators can reach the blossoms. For cane and leaf fungal diseases, a dormant-season lime sulfur or a copper or sulfur fungicide can reduce anthracnose and spur blight, and always read and follow the product label for correct use and timing.

Scouting & monitoring

In early spring, scout new canes and leaf tips for aphids, orange rust pustules on leaf undersides, and the telltale double ring of punctures and wilting tips left by cane borers, and rogue out any rust-infected plants immediately. As canes leaf out, check nodes and lower stems for the discolored lesions of spur blight and cane blight, and inspect leaves for mite stippling during hot, dry stretches. When fruit starts to color, hang a simple apple cider vinegar cup trap to detect adult spotted wing drosophila and begin checking a few ripe berries for larvae by floating them in salt water. Throughout the season, watch for crumbly or misshapen berries and mottled leaves that signal virus, and note browsing or missing fruit that points to deer or birds.

Tips

Sanitation and renewal are your best defenses: cut out and remove old fruited canes every year, clear fallen fruit promptly, and keep the planting young, open, and free of nearby wild brambles. Pick often and pick clean, because same-day harvest and refrigeration do more to defeat spotted wing drosophila than any spray.

General home-garden IPM guidance, focused on prevention and least-toxic control. Always read and follow the product label for any pesticide, including organic products. Page updated Aug 4, 2026.