Peachtree Borer
Synanthedon exitiosa
📖 Description
The peachtree borer is one of the most destructive pests of stone fruit trees worldwide, causing more damage and tree loss than almost any other pest in commercial and home orchards. The larvae feed on the inner bark and cambium layer at the base of the trunk, just below the soil line, where they are protected from sprays and predators. Their feeding girdles the tree, disrupting the flow of water and nutrients, which leads to decline and eventual death. The gummy sap mixed with frass at the tree base is the most characteristic sign of infestation. Young trees are particularly vulnerable and can be killed by a single larva in one season. Older trees can survive several years of infestation but will gradually decline in productivity and vigor.
⚠️ Symptoms to watch for
- Gummy, jelly-like sap mixed with sawdust-like frass at tree base,Bark cracking and peeling near the soil line,Yellowing and wilting leaves despite adequate watering,Reduced fruit production and tree vigor,Larvae visible under bark at the base when bark is removed,Tree decline and eventual death in severe infestations
🩹 Treatment
- Remove loose bark and probe borer holes with wire to kill larvae (organic),Apply beneficial nematodes (Steinernema carpocapsae) to trunk base (organic),Use pheromone traps to monitor adult flight (organic),Apply pyrethrin spray to trunk and lower branches during egg-laying (organic),Apply permethrin spray to trunk during adult flight period (chemical),Use chlorpyrifos soil drench around tree base (chemical — professional use)
🌿 Organic treatments
- Remove loose bark and probe borer holes with wire to kill larvae,Apply beneficial nematodes (Steinernema carpocapsae) to trunk base,Use pheromone traps to monitor adult flight,Apply pyrethrin spray to trunk and lower branches during egg-laying,Use chlorpyrifos soil drench around tree base (chemical — professional use)
🧪 Chemical treatments
- Apply permethrin spray to trunk during adult flight period
🛡️ Prevention
- Keep tree bases clean and free of grass and mulch,Avoid mechanical injury to trunks with lawnmowers and string trimmers,Paint trunks with white latex paint to prevent egg-laying and sunscald,Monitor with pheromone traps starting in late spring,Maintain tree health with proper watering and fertilization,Plant trees with the graft union above the soil line
🪴 Affected plants
- Peach Trees,Cherry Trees,Plum Trees,Apricot Trees,Nectarine Trees,Almond Trees
🦋 Natural predators
- Parasitic Wasps,Birds,Nematodes
🌱 Host plants
- Prunus persica,Prunus spp.
🔄 Lifecycle
- Adults emerge in summer (June through August) and are active during the day.
- Females lay 200-800 eggs on tree trunks, near the soil line, or in bark crevices.
- Eggs hatch in 8-10 days.
- Larvae bore into the bark and feed on the cambium layer for 9-11 months, overwintering in their feeding galleries.
- In spring, mature larvae pupate in cocoons near the soil surface.
- Adults emerge in 3-4 weeks.
- One generation per year, though some larvae take 2 years to develop in colder climates.
📅 Season
- Summer (adults); Year-round (larvae under bark)
🔎 Appearance
- Adults are clearwing moths that resemble wasps.
- Females are dark metallic blue with an orange band on the abdomen, while males are smaller with yellow markings.
- Larvae are white to cream-colored with brown heads, found feeding under bark at the base of tree trunks.
- The most visible sign is gummy sap mixed with frass at the tree base.
💥 Damage level
- Severe
🔁 Reproduction rate
- Slow
🗺️ Geographic regions
- North America
- Europe
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