Slaters are not insects. They are crustaceans and so are more closely related to shrimps than they are to insects. There are several hundred species of native slaters, but the most common slaters found in urban gardens are introduced from Europe. Slaters have several other common names including woodlice, pillbugs, and butcher boys.
Slaters thrive in damp conditions and are usually active at night. Slaters have become more of a pest in some gardens, especially in heavily mulched gardens, over the last decade or so. Slaters are usually scavengers that mostly feed on decaying vegetable matter, but they also feed on living plants.
If you’ve noticed slaters, also known as woodlice or pill bugs, invading your arrowwood viburnum shrub, you’re likely concerned about potential damage. These small segmented crustaceans thrive in moist areas with decaying organic matter. While they typically eat dead plant material, large populations can damage living plants. Fortunately, you can take steps to get rid of slaters and protect the health of your viburnum.
Understanding Slaters and Their Impact
Before removing slaters, it’s important to understand their behavior and impact on arrowwood viburnum. As scavengers, slaters eat decaying vegetation but may also consume living tissue if food is scarce. In large numbers, they can damage leaves, stems, and roots Viburnums are especially vulnerable because of their lush foliage and berries Unchecked slater infestations weaken plants and reduce vitality. Prompt action prevents extensive damage.
How to Remove Slaters from Viburnum
Follow these methods to effectively eliminate slaters
Improve Drainage
Slaters thrive in damp conditions. Ensure well-draining soil and avoid overwatering. Plant viburnum in an area with good air circulation to reduce moisture and discourage slaters.
Remove Debris
Clear fallen leaves, mulch, and other organic material providing shelter. Regularly clean around the shrub to prevent new infestations.
Encourage Natural Predators
Ground beetles centipedes birds, and other wildlife that prey on slaters will help control populations. Provide suitable habitat and food sources to attract them.
Apply Diatomaceous Earth
This natural insecticide kills slaters through abrasion. Sprinkle a thin layer around the shrub’s base and wherever slaters are active. The sharp particles penetrate their exoskeleton, causing dehydration and death.
Use Traps
Simple traps made from newspaper or cardboard rolled up and placed near the plant will capture slaters for disposal away from the garden. Check frequently and remove captured slaters.
Consider Chemicals
Insecticidal sprays specifically targeting woodlice can control severe infestations when natural methods fail. Carefully follow instructions and take precautions to protect beneficial insects.
Prevent Future Infestations
Once eliminated, implement practices to avoid reinfestation:
- Regularly inspect for pests and quickly address issues
- Maintain garden hygiene by keeping areas clean and debris-free
- Ensure plant health and vitality through proper care
Viburnums are more resilient to pests when healthy. Appropriate maintenance is crucial for preventing problems. Monitor shrubs closely and act at the first signs of slaters. Using integrated pest management techniques like these will successfully get rid of slaters and protect arrowwood viburnum from damage.
Other Common Viburnum Pests
In addition to slaters, viburnums may become infested with other pests like:
Aphids
Tiny soft-bodied insects on leaf undersides that distort growth and leave sticky residue. Treat with insecticidal soap or neem oil.
Spider Mites
Microscopic pests that spin webs and cause stippling. Control using horticultural oil or strong water sprays.
Viburnum Leaf Beetle
Metallic green beetles and yellowish larvae that skeletonize leaves. Remove by hand or use spinosad/carbaryl insecticides.
Scale Insects
Immobile pests attached to stems and leaves. Prune out heaviest infestations and apply horticultural oils or insecticidal soaps.
Japanese Beetles
Iridescent green and copper beetles in clusters that skeletonize leaves. Knock off by hand early mornings or use carbaryl/pyrethroid insecticides.
Fungal Diseases
Powdery mildew, leaf spot, and anthracnose also affect viburnum. Improve air circulation, avoid wetting foliage, and use fungicides to treat diseases.
Inspect viburnums routinely for early detection and promptly treat infestations using integrated pest management strategies. Take a proactive approach to keep pests like slaters under control and maintain the health and appearance of your arrowwood viburnum shrub.
Best Treatment for Slaters
The key to managing slaters centres on their need for moisture. Slaters dont have a waterproof wax layer on their exoskeleton, which makes slaters very prone to desiccation (extreme dryness) and is why slaters seek out moist environments.
When we mulch our gardens heavily with straw to control weeds and reduce moisture loss, we are creating the perfect environment for slaters. Of course, we cant remove all that mulch because then we have a weed and moisture-loss problem – its a delicate balance.
Slaters are terrific at breaking down organic matter and returning nutrients to the soil, but its another story when they start feeding on our seedlings. If they are causing damage you will need to do something about them.
It is very difficult to completely eradicate any pest, and the introduced species of slaters are here to stay. The best you can hope for is to suppress them (i.e., manage them) and that is why prevention treatments are so important. There are many things you can do around the garden to minimise the impact of slaters (see How to Prevent Slaters Appearing).
It pays to be persistent. What you need to do is to suppress their numbers, so that any damage slaters cause is minor or not noticeable.
What are Slaters & How to Get Rid of Them
Slaters belong to the order Isopoda, which is part of the arthropod class Crustacea. This class mostly contains marine and freshwater aquatic animals such as shrimps, crabs and crayfish. This explains why slaters are such different looking animals to other garden invertebrates such as insects and spiders.
There are about 300 species of native slaters found in Australia and they usually occur in high rainfall areas, and are found under logs, rocks and leaf litter in bushland. Introduced species are common in urban and rural areas in the higher rainfall areas of the southern half of Australia. In gardens they are usually found under mulch or in compost bins.
In their native habitats, slaters are usually scavengers that feed on decaying organic matter. In that sense they are an important part of the decomposition cycle, meaning they help return nutrients to the soil. This explains why slaters are so common in compost bins, unfortunately pest slaters also feed on living plants.
Common pest slaters include the Garden Slater or woodlouse (Porcellio scaber) and the pillbug or butcher boy (Armadillidium vulgare).
Slaters have seven pairs of legs, two pairs of antennae (one pair is obvious, and the other pair is hidden), and eyes on each side of the head.
Adult Garden Slaters (Porcellio scaber) are grey-brown in colour, flattened, and up to 17 mm long. A pair of appendages known as uropods are usually seen extending from the rear. Garden Slaters feign death when threatened.
The Pillbug (Armadillidium vulgare) is dark grey or black, up to about 18 mm long, and has the appearance of being armour-plated. Pillbugs can roll into a tight ball for protection like an armadillo – Armadillidium literally means armadillo-like. In some countries Pillbugs are called roly- polys for obvious reasons. Pillbugs dont have visible uropods.
Juvenile slaters are initially translucent white with only 6 pairs of legs, but later in the life cycle grow the seventh pair and look like miniature adults.
Females lay eggs into a brood pouch, known as a marsupium, under their bodies. Females normally produce about 40 eggs per brood and lay 1 to 3 broods per year depending on the conditions. Eggs hatch within the marsupium and the young remain there for about 2 weeks. When the young emerge from the marsupium they pass through two moults before growing their seventh pair of legs.
The young continue to moult (and grow) every week or so for the next 4 to 5 months before reaching maturity. When slaters moult they dont shed their entire skin in one go. The rear half of the body sheds first, and the front half sheds a couple of days later. Adult slaters can live for two to five years.
Dormant Pruning of Viburnum Shrubs in the Midwest by Balanced Environments, Inc.
FAQ
How can I get rid of Slaters?
How do you control insects in viburnum?
What is the pest in the Arrowwood Viburnum?
How do I get rid of viburnum leaf beetle larvae?
How do you care for arrowwood Viburnum?
Fertilize annually in the spring with balanced, slow-release fertilizer or compost. Arrowwood viburnum grows well in full sunlight to partial shade, meaning it needs at least roughly 4 hours of direct sunlight on most days. In hot climates, shade from the strong afternoon sun is ideal. Too little sun can impede flowering.
Should arrowwood Viburnum be pruned?
Arrowwood viburnum shrubs don’t need extensive pruning. Right after the plant is done flowering, prune any stems necessary to maintain the shrub’s shape. Avoid taking off more than a third of the shrub’s overall size. Remove any dead, damaged, or diseased portions of the shrub whenever you spot them.
What is arrowwood Viburnum used for?
Arrowwood Viburnum ( Viburnum dentatum) is named for its wood, which grows very straight and was used by Native Americans to make arrows. The wood of Arrowwood Viburnum is strong and flexible, making it ideal for creating arrows for hunting. The wood of the shrub is also durable and is often used for making tool handles and other wooden objects.
Can Arrowood Viburnum be potted?
Arrowood viburnum is too large to work well as a container plant. For a potted plant, choose a dwarf variety such as witherod viburnum ‘ Lil’ Ditty’, a cultivar of Viburnum cassinoides. Pot the plant in moist, well-drained soil with an acidic pH.