White worms in raspberries

Raspberry Plant Pests

Identifying Raspberry Pest and Insect
Problems for the Home Gardener

Are you having problems with Raspberry Plant Pests that are affecting the raspberry leaves, fruit, canes, or roots?

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Maintaining good management practices when growing raspberry plants will obviously help to reduce the problem of raspberry pests and insects from attacking the leaves, canes, the plant roots and the fruit.

Healthy raspberry plants will also recover more quickly from an insect attack.

Here follow several tips to remember when growing raspberries to help the plants stay healthy and resistant to pests.

What’s Bugging your Raspberries?

Be sure to pick mature raspberries as they ripen.

Even if the raspberries are not needed, or they are imperfect or severely damaged, remove them from the plant.

Decaying or overripe fruit will only serve to attract insect pests to the raspberry patch.

When pests and disease are noticed, immediate action should be taken to avoid endangering the entire harvest of raspberries.

This section deals with Raspberry Pests, be sure to check the section dealing with Raspberry Diseases as there is over-lap between these two categories.

GO to Common Raspberry Diseases

If it’s Birds that are eating your raspberry harvest,

GO to How to Protect the Raspberries from the Birds

Eradicate all wild brambles and any other wild host plants that may be growing nearby to help prevent the spread of pests.

In the spring, inspect the raspberry plants, and prune out portions of raspberry canes that have swelling, scars, or cracks, and burn the removed canes.

It is very important to observe the interval between insecticide application and when you can harvest the fruit, so always read the pesticide label carefully.

Common Raspberry Pests

Japanese Beetle – Japanese Beetles feed on both the raspberry fruit and the plant leaves, and they usually feed in groups, resulting in severely damaged fruit and foliage.

When these beetles infest a raspberry patch, they can make harvesting the raspberries a very unpleasant task!

In my experience with growing raspberries the Japanese Beetle is one of the most devastating pests.

GO to How to Get Rid of Japanese Beetles

Adult Japanese Beetles are about 1/2″ long with metallic green bodies with copper-brown wing covers. Adults emerge from the ground and begin feeding on plants in June. These beetles live about 30 – 45 days. They are most active on warm, sunny days, preferring plants that are in direct sunlight.

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Japanese Beetles are Common Raspberry Plant Pests

The above image shows how the Japanese Beetles are devouring the raspberry fruit and the leaves of the plant.

Raspberry Cane Borer – The Cane Borer causes the tips of the young stems to wilt and eventually dry up.

This insect pest is a thin, dark coloured beetle, about 1/2 inch in length, with antennae as long as its body. The Larvae of the Cane borer are white and cylindrical.

The adult female Cane Borers chew two zipper-like rings around the tips of raspberry primocanes (first season growth stems) and lay an egg between the punctures. The tip of the young stem then wilts above the point of injury and eventually dries up. The larvae tunnel downward within the cane and overwinter within the cane, killing it.

To control, remove the wilted cane tips about 5 inches below the punctured area. Burn the clippings to destroy the insects inside.

Red-Neck Cane Borer – This insect pest causes the stem of the raspberry plants to swell up to 1 1/2 inches in diameter, several inches along the cane. By late autumn, the swellings contain 1/2 inch, creamy white-coloured grubs.

The adult Red-Neck Borer is a bluish-black beetle only 1/4 inch in length, with a distinctive coppery-red colour “neck”. This beetle appears on the canes in late May or June and lays its eggs in the cane bark and the larvae bore beneath the bark, causing the swelling damage.

To control, in the Fall and Winter cut out and burn all the canes which have the distinctive abnormal swelling. If the pest problem continues, apply a pre-bloom insecticide to the canes. Check with your garden center for the appropriate insecticide or natural alternative.

Raspberry Crown Borer – This pest causes the leaves of the raspberry plants to turn red prematurely and causes the cane to wilt in late summer.

The Crown Borer is about 1 inch long, with a white body and brown head. It feeds in the larger roots (crown) or at the base of the raspberry canes.

The adult Borer is a moth that looks like a yellow jacket wasp and appears in late summer or early autumn. The adult lays eggs on the leaves, and the larvae crawl to the crown/roots of the plant/cane.

These insects overwinter under the bark just below the ground level. In the Spring, the larvae attack new cane buds and finally move downward toward the crown. It takes 2 years for the larvae to develop completely.

To control, dig and remove infested plants completely when possible and eradicate all wild brambles nearby. The insecticides for use against this pest is often not available for the home gardener, but check with your local garden center.

The Crown Borer has Bored a Hole into the Crown of the Raspberry Plant

The above image show how the Crown Borer has bored a hole into the crown of the raspberry plant.

The (white) Crown Borer Larvae inside the Crown of the Raspberry Cane

The image above shows the white Crown Borer larvae inside the crown/root at the base of the raspberry cane.

Tarnished Plant Bug – The sucking of this pest results in deformed raspberries. Dried up druplets may be an indication that the Tarnished Plant Bug is the pest.

To control this raspberry plant pest, keep the raspberry patch and the surrounding area as free of weeds as possible.

The Tarnished Plant Bug

The above image is a Tarnished Plant Bug.

Raspberry Fruit Worm – The feeding of this pest causes elongated long holes in the leaves of the raspberry plant, which sometimes destroys bud clusters. The leaves will appear ragged and torn looking.

The Raspberry Fruit Worm adult is a small, 1/8 inch, light brown beetle covered with short hairs. The larvae are slender, creamy white, approximately 1/4 inch long and found inside the hollow part of the fruit.

Adults insects are active in May and June as raspberry buds emerge. They begin feeding on buds and tender leaves, and later on blossoms. Larvae are present in developing fruit and are most often observed at harvest.

Watch for leaf feeding around developing fruit buds. Adult Fruit Worms can be detected by shaking bud clusters into a dish or tray but quiet observation is the best way to detect these insects.

To control, application of a prebloom insecticide is recommended. It is also recommended to cultivate around the plants to help destroy pupae.

Sap / Picnic Beetle – The Sap or Picnic Beetle is a nuisance in raspberry patches as they feed on damaged, overripe, or decomposing fruit.

The Sap Beetle is about 1/4 inch long, black with cream markings. There are many different species of Sap Beetles.

These insects overwinter as adults. They emerge in the Spring and lay eggs near fermenting and decaying plant material. Larvae feed for about three weeks and then pupate, emerging as adults in late June or July. They take about 35 days to develop from egg to adult, with one generation each year.

To control, keep the garden free of overripe fruit (and vegetables). Remove any damaged, diseased and overripe fruits on a regular basis.

Baits (outside the garden area) may be used to trap beetles. Apple cider vinegar or a mixture of yeast, sugar and water combined with a few drops of liquid detergent will drown the beetles. Be sure to discard trap contents frequently and rebait the traps.

Commercially prepared bait that contains the insecticide carbaryl or bifenthrin may be helpful. It is very important to observe the interval between insecticide application and when you can harvest the fruit, so always read the pesticide label.

The Sap Beetle

The above image is a Sap Beetle.

For Additional Information about raspberry pest problems, See Also:

Ontario Ministry of Agriculture and Food

University of Maine – Home and Garden

For more detailed information about growing raspberry plants, here below, (or use the navigation bars) are links to pages which will be helpful in your berry growing endeavours!

GROWING Raspberry Plants

PLANTING Raspberry Plants



Growing Raspberries from SEED

Raspberry Plant CARE
(Fertilizing/Watering/Spraying/Sun Requirements)

HARVESTING Raspberries

PRUNING Raspberry Plants

Raspberry PESTS

ORGANIC Raspberries

TOP of Raspberry Plant Pests Information

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What’s eating my plants?

First, clear the names of any suspects that couldn’t possibly have caused the damage. For a start, you know it’s not a sap sucker – they siphon juices out of the plant – so that eliminates aphids, mealybugs and mites.

Next, look at how much plant material has been removed.

If big chunks have disappeared, then clearly a large animal has been at work.

Possums will be your number one suspect. Listen at night for possum thumps on the roof or for the screeching and gurgling sounds of their nocturnal antics. Yates Possum Repellent Spray helps protect your precious plants by deterring possums from browsing on sprayed plants. Commercial possum deterrents can work well if you’re persistent about application. Otherwise try applying home-made remedies like fish sauce or moth flakes, or festoon plants with balls of dog hair or Dynamic Lifter knotted into stocking toes. While these methods work with some possums, there are no guarantees. Often it’s a matter of learning to live with the possums’ nocturnal snacking.

Rats can also eat plant parts, particularly starch-filled sections such as bulbs, swollen stems or ripe fruit. Rats are definitely garden undesirables that can be controlled with a rat bait (called a rodenticide). Choose one that’s most suited to your needs, and make sure you follow instructions carefully. Ratsak is a multiple feed product, which means a rat must eat the bait over a number of days in order to ingest a lethal amount. Ratsak 1Shot is faster acting and more moisture resistant but, like traditional Ratsak pellets, should be kept in as dry a spot as possible. Here’s a tip when baiting outdoors: place bait inside a T-shaped piece of plastic plumbing pipe where it will be protected from the rain and from inquisitive dogs and cats.

Birds are rippers and tearers. They use their beaks to tug at pieces of plants and they’ll rip through the bark searching for fat, juicy borers. If birds are causing lots of plant damage, try some of the bird repellents, or resort to physical barriers such as netting.

problem: worms in raspberries

I copied and pasted the non-pesticide control options below from UMass Extension’s publication http://extension.umass.edu/fruitadvisor/news/spotted-wing-drosophila-drosophila-suzukii
These will be difficult to control without the use of pesticides. Check the pesticide list in the guide above, too, because some of the options are considered ‘natural’, like pyrethrins and spinosad.

The first step in dealing with this new pest is identification. Spotted Wing Drosophila is a small vinegar fly. Both males and females have red eyes. Males have two spots on their wings, which is a key identifying feature. Females lack the wing spots but have a robust and serrated ovipositor that distinguishes them from other species of fruit fly. Seeing the ovipositor requires some magnification; a hand lense will do.

Overwinter as adults and maybe pupae in leaf litter, duff, and rotting fruit

  • Adult flies live for up to 2 weeks
  • Females can lay 300 eggs
  • Can develop from egg to adult in as little as 8 days

  • Likely to have over 10 generations per growing season


  • Females lay eggs in fruit
  • Larvae eat flesh, which renders it unmarketable or causes customer discontent (infested fruit ‘melts down’ in 2 days)
  • Egg laying introduces fungal pathogens, which rot fruit


  • Unlike other fruit flies, SWD attacks sound ripening fruit
  • Once eggs laid in fruit, no longer able to control with pesticides
  • Short lifecycle and overlapping generations make spray timing difficult
  • Requires sprays near harvest time
  • Requires multiple sprays which can lead to pesticide resistance



  • Use traps to establish presence and abundance of SWD
  • Set traps out prior to fruit ripening to establish onset of infestation
  • Check traps frequently (at least once per week)
  • Replaice bait weekly to maintain effectiveness (don’t dump old bait on ground; remove from field)


  • Use sticky cards inside traps or sieve contents to and check to confirm presence of SWD (males are easiest to see)
  • Use hand lense and ID key to help with ID
  • Record date and number of SWD caught to determine trend


Sanitation – keep area free of overripe fruit to reduce habitat for build up; eliminate wild hosts as much as possible

Exclusion – small areas can be covered with fine netting or row covers prior to fruit ripening to keep SWD out

Biological Control – researchers are looking for suitable predators, parasitoids, pathogens and other beneficial organisms that might help suppress SWD populations.

There are small, white worms in my raspberries. What are they and how can they be controlled?

The small, white worms are likely the larvae of the spotted wing drosophila. Spotted wing drosophila adults are small, yellowish brown flies. Males have distinctive dark spots on their wings, hence the name spotted wing drosophila. Female adults have serrated, saw-like ovipositors and lay eggs in soft, ripening fruit. Spotted wing drosophila larvae are white, 1/8 inch long maggots.

Spotted wing drosophila feed on soft, thin-skinned fruit. Their preferred food choices are raspberries (especially fall cultivars), blackberries, and blueberries. However, they also feed on grapes, strawberries, cherries, and aronia.

Control of spotted wing drosophila is difficult. In the home garden, sanitation is the most practical control measure. Promptly harvest ripe fruit. Remove and dispose of over-ripe, damaged, or rotting fruit. Dispose of berries in a manner that prevents flies from emerging and reinfesting sound fruit.Insecticides are a possible control option. However, most commonly available garden insecticides have preharvest waiting periods of several days, making their application to ripening fruit impractical. If you decide to use an insecticide, select one with a short preharvest waiting period (such as one day) and carefully read and follow label directions.

Controlling Raspberry Fruitworms: Preventing Fruitworm Damage On Raspberries

Raspberry patches give home gardeners easy access to the tasty fruit these canes produce, making berry-picking a fun experience for the whole family. Like other berries though, raspberry fruits are frequently invaded by worms that can ruin a harvest. These raspberry worms are the larvae of a tiny beetle, known as the raspberry beetle (Byturus unicolor).

The raspberry fruitworm beetle reaches up to about 1/5 inch long; its reddish brown body is covered in tiny, short hairs. Adults feed voraciously on leaves of raspberry canes, favoring the newest canes and leaves, but may spread further when populations are high. Mating takes place on or near raspberry flowers, where eggs are deposited.

Fruitworm Damage on Raspberries

Adult raspberry fruitworm beetles appear from mid-April to mid-May, eating the surface tissues from raspberry leaves or skeletonizing them entirely. They may feed on opening flower buds when they appear, if numbers are large — even whole bud clusters are sometimes consumed. However, the damage from the adult beetle is usually insignificant to the plant as a whole.

Raspberry worms, on the other hand, can cause serious economic damage. When these tiny worms hatch, they find themselves inside or up against individual fruit caps. The larvae burrow into the raspberry receptacles, sometimes causing fruits to dry up or drop prematurely. Infestation ultimately results in the downgrading of commercial harvests when raspberry worms are found among the fruit.

Controlling Raspberry Fruitworms

If you pay close attention to your raspberries throughout the spring, you may be able to catch the tiny raspberry fruitworm beetles shortly after emergence, but before they’ve begun to lay eggs. Handpicking is possible, even though these pests are small, if you are determined. Dropping them into a bucket of soapy water will kill them quickly.

Killing raspberry fruitworms naturally is a goal of most gardeners, who prefer not to add pesticides to home-grown fruits. Spinosad is a microbial pesticide allowed in organic gardens and considered totally harmless to humans, but you must restrict the use of this chemical to evenings since it is dangerous to bees while wet. Spray raspberry canes with active beetle populations as soon as they are noticed, or wait until flower buds swell to target raspberry worms specifically. A second application after bloom may be required to kill all the worms.

After harvest, raking or shallowly cultivating the soil around your raspberry canes can break up pupating larvae in the soil. If you keep chickens, this is a great time to let them in the garden to help destroy the tasty beetles.

Preventing White Worms in Raspberries

October 18, 2015 lawanda Newspaper Columns

Imagine waking up to a stack of steaming golden pancakes or a big bowl of cereal topped with raspberries fresh from the patch. Suddenly, you notice a white squiggly thing inside one of the berries. It looks like a little worm! Looking closer, you see squigglers in all the berries. There goes breakfast! The little white worms are the larvae of fruit flies. There are many kinds of fruit flies, but determining which one ruined your breakfast isn’t important, because prevention is the same no matter who the culprit. There are several things you can do to prevent fruit flies from spoiling your raspberries. You probably know that ripe fruit attracts fruit flies, and may have experienced an indoor invasion if you’ve left fruit out on the kitchen counter. Clearing the raspberry patch of ripe fruit every single day, especially those berries that are overripe or have fallen to the ground, will deter fruit flies from arriving and breeding. You may want to pick the berries just before they become perfectly ripe. Do not compost unwanted berries, because the fruit flies will simply move their breeding ground to your compost pile. Keep the raspberries pruned and thinned so they do not become crowded. Fruit flies prefer shady, humid environments so space between the plants will make the patch less welcoming. Except for rain which is unavoidable, do not water raspberries from overhead. Use a soaker hose, drip irrigation, or simply lay your garden hose in the patch and let it run at a very low rate. Set a timer so you don’t accidentally let the hose run all night! As soon as the summer harvest is finished, remove old canes by cutting them at ground level. Trellis sprawling types to allow air to circulate. Burn the prunings instead of composting them as most compost piles do not get hot enough to kill fruit fly larvae. Shallowly cultivate the soil in your raspberry patch to expose larvae in the soil to hot sun or cold winter temperatures which they can’t survive. If you have everbearing raspberries, and fruit fly larvae has been a problem in the past, you may want to forgo the fall harvest for a few years. Fruit flies are more prevalent in late summer than they are in June. Pruning the canes to the ground immediately after the summer harvest will give the flies less of an opportunity to procreate, at your house anyway. You can make your own traps to catch fruit flies by mixing 1 T. baker’s yeast and 4 T. sugar with 12 oz. of water. Let it ferment for 24 hours. Get some old deli containers and punch holes in the tops. Fill each with about an inch of the bait and hang the traps 3-5 feet above the ground. Replace the bait every week or two.

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