Insect and Mite Pests of Raspberries

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 Aphid | Mite | Crown borers | Fruit worm| Raspberry sawfly | Wasps/hornets/yellow jackets

An important part in the production of any fruit crop is to know what type of insects could cause production losses. A crop is at risk throughout the fruiting cycle. Insects can attack plants during flowering, fruit formation or just before harvest of the plump, juicy berries. A successful pest management program includes: insect identification; pest number and damage monitoring; what population numbers warrant control and knowing when the pest can be effectively controlled.


Green Peach Aphids

  • 1-3 mm long, soft-bodied, pear-shaped
  • main identifying feature: cornicles (tail pipes protruding out of the back end)
  • variety of colors: green, yellow, pink, white, bronze, dark-brown or black
  • adults may be winged or wingless
Life cycle
  • overwinters as eggs on the host plant
  • eggs hatch into "stem" mothers which bear live young; these live young, in turn, bear more live young
  • each mature aphid can produce 50-100 offspring
  • 15-30 generations may be produced per season
  • they can reproduce either sexually or asexually (parthenogenesis - being able to reproduce from eggs which have not been fertilized)
  • males are not produced until fall
  • mating occurs in the fall
  • either an egg is produced; or, another stem mother, which lays the overwintering eggs
  • symptoms of feeding damage are leaf discoloration, a flattened appearance and ,in severe cases, wilted plants
  • when aphids feed, they puncture plant capillaries; the plant then pumps the sap into the aphid; exudate (excess sap) comes out the back end of the aphid
  • this exudate is called honey dew
  • honey dew makes the leaves and fruit sticky
  • honey dew can also be a nutrition source for the growth of sooty mold fungi (not harmful to the plant, but it can make the fruit unsalable)
  • aphids seldom cause much direct injury, unless present in large numbers
  • they may transmit viral diseases
  • generally, they are found in clusters on the new growth, stems, buds or on the underside of leaves among the veins
  • look for symptoms weekly
  • consider the weather conditions, presence and abundance of natural enemies, and the value and stage of the crop before spraying
Cultural control
  • start with clean stock
  • there are a wide range of natural predators: lady bugs, lace wings, and predatory wasps

  • .5 mm, oval, greenish-yellow with 2 irregular dark spots on the back
Life cycle
  • overwinters as an egg, a nymph or an adult on old leaves on the ground or in
  • cracks and crevices of old canes
  • when the plant starts to grow, the mites mate and lay eggs on the leaf underside
  • eggs hatch and begin to feed
  • there can be several generations overlapping
  • hot, dry weather favors population explosions


Spider mite damage
  • feeds on the leaf underside
  • feeding damage causes yellow spots (mottling or stippling) changing to silver or bronze, then brown with leaf crinkling and curling
  • leaves may dry up and fall prematurely
  • high populations will cause loss of plant vigor
  • feeding on primocanes stunts cane growth, therefore, reducing crop potential for the following season
  • dusty conditions will create a larger mite population, causing more problems
  • injury can be worse after harvest
  • examine for webbing between or under the leaflets
  • webbing indicates a very heavy infestation
  • damage is most noticeable in dry areas of the field
  • diagnostic tools: breathe on leaflets, this causes the mites to scurry about, or tap the leaf over a white sheet of paper to make the pest visible
  • check the canopy top of the fruiting canes
Cultural control
  • spider mite predators become established as plants mature
  • irrigate regularly to avoid water stress on plants
  • eliminate weeds that can be used as alternate hosts
Chemical control
  • begin the chemical control when mites first appear and repeat as necessary
  • ensure leaf undersides are well covered with insecticide
Crown Borers

  • the adult is a clear-winged moth, 25-30 mm long
  • the abdomen is black with yellow bands and stripes on the thorax
  • new larvae are 3 mm long, whitish with brown heads
  • mature larvae are 25 mm long with white bodies and brown heads
  • larvae have six short legs

    Raspberry crown borer mature larva
Life cycle
  • adults appear in August or September females lay 130-150 eggs on the leaf undersides (2-3 per plant)
  • eggs hatch in September and October, larvae crawl down the cane to the base
  • overwinters in tiny blisters on cane just below soil surface
  • larvae emerge the following spring and feed on primocanes through the summer
  • by October, the larvae are nearly full grown and spend the winter in the feeding burrows
  • they burrow further into the crown to feed the following summer
  • in July, they tunnel and pupate a few centimetres near the outside of the cane
  • it takes 2 years to complete the life cycle
  • slows cane growth with the possibility of cane death
  • reduced yields
  • new canes are girdled near the ground
  • canes become spindly and are easily broken
  • may also form galls
  • dig the crown out, look for holes and sawdust
Cultural control
  • after harvest, prune out loose canes and ones with galls
  • during the summer, remove and destroy wilting canes

Raspberry canes damaged by crown borer

Fruit Worm

  • the adult is a small brown beetle, 4 mm
  • the larva is small (6 mm) and whitish-brown
Life cycle
  • adults lay eggs in early spring on or near the developing blossom clusters and green berries
  • larvae feed in the berry and may be in the fruit at harvest
  • mature larvae drop to the ground and pupate
  • overwinters as an adult
  • presence of yellowish larva on the harvested fruit, making the fruit unsalable
  • adults feed on leaves before they unfold, so leaves have a tattered appearance
Chemical control
  • spray when blossom bud clusters separate and just before blossom opening
Raspberry Sawfly

Sawfly damage

  • the adult sawfly is 5.5 mm long, black with yellowish-red markings
  • the larva is 12 mm long, light green in color, all body segments, except the head, possess a number of whitish bristles
    Life cycle
  • adults emerge in the spring (blossom time)
  • they lay eggs in the leaf tissue
  • larvae feed during the summer
  • the larvae drop to the ground, construct a cocoon and overwinters as larvae
  • they pupate in the spring
    • they feed on leaf underside, flower buds, young fruit and tender bark of growing shoots
    • initial damage appears as small holes in leaves
    • they will completely devour the leaves leaving elongated holes between the larger veins
    • the feeding results in weak plants
    • during July, watch for holes in the leaves
    Chemical control
    • often controlled when spraying for other pests
Wasps/Hornets/Yellow Jackets

  • some adult paper wasps are black with yellowish-white markings; others are black with bright yellow markings
  • a colony consists of workers (sterile females), drones (males) and the queen
  • only females have the stinger
  • wasps are hunters and are useful in controlling caterpillars and flies, but they can become pests in the berry fields
Life cycle
  • warm, dry springs produce larger wasp problems in August than do wet, cool springs
  • in spring, the fertilized queen emerges from hibernation
  • she chooses a good spot (a hole in the ground, such as a mouse burrow, a tree branch, bush, under the eaves or in the walls of a building) and begins to build a nest by chewing wood fibers into a pulpy mass
  • the queen lays eggs which hatch into legless, blind larvae
  • larvae last 2 weeks, then pupate
  • in 3 weeks, adult females emerge and begin to tend the queen
  • in August, male and new queen cells are produced
  • in early fall, the males and new queens emerge, mating takes place on the wing
  • males die and fertilized queens overwinter in protected sites like stumps or hollow logs
  • the nest is abandoned and never used again
  • wasps are attracted to the ripe or injured fruit as a source of sugar and moisture
  • dangerous to pickers as the sting is painful and ,in some cases, may cause an allergic reaction which could lead to death
Cultural control
  • prompt harvesting of ripe berries and clean picking practices
  • hang a piece of meat or fish over a bucket of water with detergent in it; wasps will take a mouthful and fall into the water and drown
  • 2 litre soda pop bottle with about 5 cm of soda pop left in the bottom attracts wasps into bottle
  • basin or some other shallow container, with a few inches of water in it, add syrup (like maple); the insect is drawn to the syrup and drowns in the water
  • set nest on fire with a torch
  • knock nest into a sack and burn it
  • carry out control methods after dusk, after the wasps have settled for the night
  • wear protective clothes (coveralls, gloves hat netting with ends tucked into the collar) when dealing with wasps
  • if necessary to use a flash light, don't hold the flashlight, set it aside to shine on the nest
  • some of the insects will become agitated, leave the nest angry and go for the light, possibly attacking it
Chemical control
  • spray insecticide into the entrance of the nest, do this after dark
  • for ground nests, stuff insecticide soaked cotton or steel wool into the nest
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For more information about the content of this document, contact Shelley Barkley.
This information published to the web on November 26, 2001.
Last Reviewed/Revised on November 21, 2016.